Literature / So I'm a Spider, So What?

No way! Why am I a spider!?

"Well, though I hate to admit it, I've been reincarnated as a spider."

— Chapter 1

So I'm a Spider, So What? (Kumo desu ga, Nani ka?) is a Web Serial Novel series written by Baba Okina. In an alternate world, as their final act, a great Hero and Demon King unleash a cataclysmic magic. Said magic tears through dimensions and erupts into a Japanese high school classroom, killing everyone inside instantly. But instead of staying dead, those present find themselves reincarnated into the alternate world.

In a subversion of the usual Isekai story, our protagonist is a quiet, lonely girl who is reincarnated not as the next Chosen One... but as a spider. No, not a Cute Monster Girl spider, but the lowest level of spider monster Mook that you would kill in a starter RPG cave. Now she has to use all her wits in order to survive in the world's deadliest labyrinth.

The series has been adapted into a Light Novel and Manga that unlike the other media is told only from Kumoko's perspective, both of which have been licensed by Yen Press, and an Anime Adaptation by Millepensee Inc which began airing on January 8, 2021. Also has a Spin-Off manga series, So I'm a Spider, So What? Daily Life of the Four Spider Sisters, where four Literal Split Personalities the main character generated with a skill partway through the story gain their own independent bodies. Hilarity Ensues.

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This work contains examples of:

Tropes A-M

• Abnormal Limb Rotation Range: The Puppet Taratects are capable of doing this towards their puppet bodies that they control with their threads. This causes the Balto's butler to advice him to never opposed the demon lord as he once observed, during his night patrol, of Riel doing an Exorcist Head towards him as she guards Shiraori. Balto muses on the fact that the report can pass off as one horror movie scene, though he takes the advice by heart.
• Accidental Murder: In the Light Novel, the first time Kumoko killed someone it was an accident. While she was pissed about them torching her home and decided to punish the group responsible, she didn't expect briefly turning her evil eyes on them would be enough to kill them instantly. Afterwards she just goes 'Oh, hm, they're worth a lot of exp, they started it and in for a penny, in for a pound, right?' and kills the rest.
• Acquired Poison Immunity:
  • Kumoko gets a rather high poison resistance (and Corrosion resistance, too) from being forced to hunt for prey in a dungeon where every creature is poisonous to various degrees.
  • Turns out in this RPG Mechanics Verse, you can build resistance to anything this way. Including building resistance to the Earth element by flinging boulders at yourself.
• Actor Allusion: Multiple examples:
  • This is not the first time Aoi Yūki has voiced someone related with spiders, as she voiced Gwen Stacy, aka Spider-Woman, in the Japanese dub of Spider-Man: Into the Spider-Verse. Extra points as Kumoko's exoskeleton is very similar to Spider-Gwen's outfit.
  • Likewise, Kumoko's numerous references to being a Magical Girl from the webnovel, such as "If someome offered to make me a magical girl right now, I'd say 'Yes'", become allusions in the anime as a result of the voice actress' previous magical girl roles in Healin' Good♡Pretty Cure, Symphogear and especially Puella Magi Madoka Magica.
• Act of True Love: In volume 12, Yaana pushes Julius from being crushed by a Queen Taratect's leg and her final monologue has her doing the deed due to her feelings for Julius.
• Adaptational Badass:
  • In the web novel, after the taratect squad fails to eliminate Kumoko, Mother seemingly has no more cards to play because it's implied she can't find her. In the light novel, she was just waiting for Kumoko to leave on her own since Mother can't enter the Upper layer apart from egg laying spots, but can exit the labyrinth entirely. She also puts up a more active resistance against her soul being attacked, though it's equally unsuccessful.
  • In the Web Novel, Kumoko achieves Divinity Area Expansion LV10 and apotheosis after finding an ancient abandoned MA energy harvesting facility under a distant forest even Adventurers don't venture out to, defeating its robot defences, stealing the facility's MA storage/power core and the MA cores of all the robot defences she destroyed, and using knowledge from the Taboo skill to unite her magic and the cores' MA energy within her own body, which levels up her. In the light novels this is replaced with the G-Fleet, which takes the combined might of Kumoko, Ariel, Gyurie, Dustin, and Potimas to defeat, with Kumoko achieving it by eating the continent-destroying GMA Bomb and absorbing all of its MA energy when it explodes within her.
  • In the anime, Earth Dragon Gakia fought Ariel alone and gave her a run for her money as opposed in the light novel where Gakia, alongside with his subordinates, fought Ariel.
• Adaptation Decay: While the basic beats of the story remain the same early on, the story starts going in different directions after Kumoko leaves the labyrinth as this point marks the increased complexity of the plot and the start of her more amoral behavior in the web novel, which is vastly toned down in the light novel. Villains are often made to be more dangerous, Kumoko's power escalation is turned down and characters and relationships begin to differ wildly. This ends up leading to entire arcs that are light novel only and a plot trajectory clearly aiming for an entirely different ending.
• Adaptation Expansion: The light novel adds a significant number of new scenes that were not present in the web novel, such as the inclusion of a massive snake monster being killed by Alaba to set up Kumoko believing she couldn't take him in a straight fight, so she uses Sloth instead. It also reveals some information early on that was intentionally kept secret in the Web Novel such as her plan to eat Mother and an entire novel devoted to eliminating her and her underlings. The manga takes it slightly further than that and spoils the presence of Ariel and the Mind Rape effects of Taboo. There's also an entire novel based around the conflict between Ariel and Kumoko, but the cost of this expansion is severely cutting down on portraying the other events going on at the time and introducing a few plot holes.
• Adaptation Explanation Extrication: In the web novel, Gyurie and Kumoko went out drinking after she left the labyrinth because he wanted her to stop running around causing problems by killing people. After she got drunk and opened up, he decided it was capable of getting along with her and even liked her a little. Afterwards, he went to speak to Ariel and said that her recently changed personality and tone of voice was similar to Kumoko. However, in the light novel, this meeting with Kumoko happens after he has this conversation with Ariel, doesn't involve Kumoko opening up and still ends with Kumoko being warned not to cause more problems. Except she really hasn't done anything severe enough to need be warned. Meaning Gyurie knows her personality without ever having spoken to her for real and wants her to stop doing... nothing much?
• Adapted Out:
  • Shun and the other reincarnated characters are completely absent from the manga adaptation which, aside from a brief cameo in Chapter 23.2,^note Kumoko wondering if her classmates were reborn like she was is accompanied by a Flash Forward panel showing Shun and Feirune. focuses exclusively on Kumoko's misadventures.
  • The anime removes Kumoko fighting an Elroe Gunesohka, and merges parts of that battle with her fight against Rend the fire-dragon.
  • Rend's "fight" with the Queen Taratect is left out of the anime adaptation, with Kumoko coming across the aftermath and being confused as to why a severely wounded and severely pissed-off fire dragon is attacking her, and wondering what the heck happened to it.
• Adaptive Ability: A part of the skill system. Hit an enemy with enough non-lethal fire strikes and it will start developing fire resistance. Same goes for other elements, poisons, magic, psi attacks, or even straight up physical damage.
• Adventure Guild: Exists in-universe though largely out of focus. Ariel maintains a membership so she can take advantage of the perks while traveling.
• Aerith and Bob: There are names like Sophia and Ariel and then there are those like Gyuriedistodiez (usually called Gyurie) and Merazofis.
• Affectionate Parody: Sophia's time at the academy is a brief joke twist on the villainess isekai genre that was becoming popular at the time. It's a perspective flip of what is already a perspective flip based genre with Sophia as the evil reincarnater and poor Felmina as the misunderstood villainess. As such, she rather obviously stumbles through the otome game plot throwing everything into chaos with charm magic that she pretends she isn't using and treating high nobility like playthings for her to use until she tires of them. Meanwhile, the villainess correctly identifies her as a threat to natural security but fails utterly because she's way out of her depth, resulting in the stock denouncement scene.
• The Ageless: The staggeringly expensive Immortality skill. Though you'll never age or be killed by anything inside the System after buying it, you can still be killed by being removed from the system. As Kumoko realizes after gaining it via evolution, only to lose her current body to Ariel's System expelling Abyss magic. Also, if you lack a regeneration ability, you can potentially be crushed into a paste and still be alive.
• All for Nothing: In the Web Novel, this is ultimately what the Dustin Faction's efforts amount to. They sacrifice countless lives to the meat grinder in a desperate effort to stop Shiraori from collapsing the System, as that would result in even more lives being lost as a byproduct. Not only do they fail to stop her right at the finish line, Shiraori turned out to have prepared a contingency method that lets her safely collapse the System while protecting the souls of everyone in the System from the very blowback that the Dustin Faction was fighting to stop, essentially solving the entire problem by herself by accomplishing the goals of both factions.
• Always Someone Better
  • As Shiraori tells Sophia, she's weak, little more than prey unless she becomes strong. But even if she becomes strong, there'll be someone else out there even tougher that can still wipe the floor with her. The only way to be safe is to be such a big fish that no one can hurt you. Shiraori herself is at least ten times Sophia's strength and yet is still only something like the fifth biggest fish around behind Gyurie, Sariel, D and Meido, all of whom are mid to high ranked gods. Though Gyurie is a smaller fish that she realizes.
  • Though he tried to be humble about it, Shun believed that he could make an impact and change the course of the war because he was the Hero. However, his failure in the elf village and seeing that Shiraori's group didn't even consider him an obstacle made him realize that he was actually something of a small fry. He resolves that he needs to get stronger and have a better grasp of what he can do and how he can do it if he wants to carry on Julius' will.
• Amusing Injuries: Since Sophia can survive at least one fatal attack per day regardless of source and isn't a particularly sympathetic character, Shiraori tends to find it amusing to kick her so hard that she nearly snaps in two when annoyed. If it doesn't kill her, great! If it does, she'll come back to life anyway.
• Anatomy of the Soul: As the story progresses it's revealed that many skills directly affect the soul, such as Parallel Will splitting off a portion of the soul to create two minds. This leads into The Reveal that skills are all modifications of the soul and skill points are the soul's excess energy. When a person or monster dies the skills and skill points are converted into energy; a portion is given to the killer as XP while the rest is absorbed by the System.
• And the Adventure Continues: In the Web Novel's epilogue, Shiraori survives the war, captured by D and made into her kin, now so horrendously enfeebled she's literally as small and weak as a small spider once again. She is to be remanded to the care of another of D's kin until she regains her strength so she can continue to amuse D in the future. Shiraori's response is to swear that she will get even stronger and escape from D one day. Her adventures are just getting started.
• And Then What?: Felmina asks Sophia what her plans are once the System is destroyed; Sophia realizes she had none. Shiraori's own answer isn't much help for the other reincarnators.
  Shiraori: ...run away.
• Angst? What Angst?: Invoked. For basically her whole early life, Kumoko has a rather blase and cheery attitude about life in the Elro Labyrinth, seemingly taking everything in stride. She even remarks at one point that she should be traumatized after something that just happened but realizes she isn't reacting emotionally. However, as Shiraori, she gets drunk often and has a habit of telling people at length how horrible the place was and how often she thought she was going to die, indicating she actually was traumatized by her upbringing but simply lacked the emotional awareness to process it properly.
• Anthropomorphic Food: "D" makes some Valentine's day chocolates, which moves around and wails yet still tastes like chocolate. Even Shiraori won't eat it.
• Anti-Magic
  • The underground facility has an anti-magic field that blocks any spells and most skills, which themselves are applications of high level magic. It's possible to partially negate this field by copying the anti-anti-magic field the security robots use.
  • Gyuriedistodiez and other true dragons of his race can produce anti-magic barriers capable of suppressing even other gods. Potimas reverse-engineered their barriers to create his own anti-magic.
• Armor-Piercing Question: When Sophia is seemingly completely unrepentant for her mind controlling of the students and teachers at school to feed her hunger for blood no one seems to be able to get through to her. Merazofis steps in and she thinks she has a new ally... until he slaps her and asks her one simple question.
  Merazofis: "Ojou-sama, would your parents be proud of you as you are now?"
• Ascend to a Higher Plane of Existence
  • Beings that gain a particular strong Divine Area undergo apotheosis as the Divine Area is the core of the soul and the source of most of its power. Kumoko undergoes apotheosis as a result when she absorbs the MA energy from a secret lab, which finally grants her enough strength to go from level 9 to 10. Ruler titles help to expand the Divine Area, but at the same time the Ruler skills and authorities decrease the size of the Divine Area.
  • Hinted at. Unlike monsters, humans do not undergo evolution at any level people have actually reached before. However, they speculate that humans may actually evolve at level 100. Whether this is true or not and whether it would be to something more than human is up in the air, however, and the existence of Ariel may serve as evidence that humans simply do not have a level cap.
• "Ass" in Ambassador: The man sent to convince Kumoko to leave Sariera was rude and domineering, which of course made Kumoko avoid him at all times. She later speculates he was chosen specifically because he was likely to cause an incident that could be used as grounds for a war.
• As You Know: Averted. The only detailed explanations from someone who knows things is when they're talking to someone who doesn't. As such, when Kumoko is figuring out skills she'll explain at length what she's learning because it's new to her too, but when she hits Taboo 10 and learns the truth of the world her behavior and personality take a sudden 180 for no clear reason. When talking to those like Dustin or Gyurie who are also in the know they don't bother to explain the actual subject. It's not until Kumoko has to explain things to Sophia and Wrath that the audience finally figures out what the hell was going on back then.
• Attack! Attack... Retreat! Retreat!: Kumoko was doing pretty well hunting Elro Ferects until she found their nest. It's even in the chapter title.
  Chapter 23: I'm sorry that I got carried away. Please forgive me!
• Attack of the 50-Foot Whatever: The Myth Class monster Fenrir and Kumoko's "Mother", the Queen Taratect, are huge compared to humans. The Fenrir is even described as the size of a mountain, though it makes no actual appearance in the story.
• Attack Drone:
  • In volume 7, after Kumoko & Ariel's party stumble upon the underground ruins and accidentally activating the G-fleet weaponries, one of the weapons was a drone designed to bombard target locations by dropping meteors. Gyurie is tasked in dealing with those weapons as he is the most suitable person amongst the powerhouses of Kumoko, Ariel, Dustin & Potimas.
  • Potimas, with his vast knowledge of the ancient civilization, has a massive arsenal of Glorias. These Glorias are Soul Powered Engines that even has the Anti-Magic properties from the Dragons, though they become useless once Shiraori decides to get serious.
• Audible Sharpness: Kumoko thinks her front limbs, which look like scythes, are so sharp that they ought to be making appropriate sound effects. Alas, she is still as silent as ever.
• Automaton Horses: In book 11, Julius's party has spent ten days chasing after a migrating phoenix. They've had to sleep and eat while in the saddle, and no mention is made of having to let the horses rest. Considering the setting it's possible their horses actually have the Exhaustion Nullification skill in-universe, but this is not explicitly stated.
• Awesome, but Impractical: Abyss magic is extremely powerful and seemingly cannot be blocked. However, it's also so complicated that it cannot practically be used in a fight and is barely usable at all. The area of effect on some of the spells is also very dangerous. Kumoko gives up on it after one use while Ariel suspects that it was never intended to be used as a means of war but rather of execution: Death via abyss magic boots the soul of the cycle of rebirth and turns it into mere energy. This is the second reason Kumoko never bothers with it again: Anything killed by Abyss Magic grants no exp.
• Awful Truth: Level 10 Taboo reveals the actual nature and history of the Skill system: humans destroyed the entire planet centuries ago by creating Life Stream eating Magitek. The System is essentially a purgatory placed upon humanity where they must fight and die over countless lifetimes to restore the energy they stole. The alternative is letting the world die, killing everyone and rendering every sacrifice up till that point by the comatose goddess Sariel and all the people who died basically pointless. Most people go crazy to some degree after learning this. However, it's less the fault of humans than the Taboo skill actually implies, which is suggested to be intentional on the part of D. While humans did play a role, there were pretty solid reasons for not stopping and the true dragons were the ones who actually dealt the death blow to the world by taking the last of its energy and fleeing, while Sariel could have cleaned things up but instead chose to do nothing but give a warning that had no credibility to it. Taboo doesn't tell the full story but instead emphasizes the recklessness of the humans and their selfishness towards Sariel. When Shun hits Taboo 10 as a result of Shiraori's manipulations, someone that is implied to be Sariel fills the gaps in the record, which allows him to maintain his stability.
  • Shiraori and Gyurie decide not to tell Dustin that the higher God that helped create the system is an aloof being that regards their world as nothing but a toy for her amusement and that everything that has ever happened to anyone was solely for her fun, since that would not be good for his mental health. They're proven right during the final battle when D tells everyone that she hopes they'll entertain her.
• Aw, Look! They Really Do Love Each Other: For all the things Shiraori says about Ariel, she really does care for her to the point she is the main reason for saving the Goddess. This eventually comes to a head after the human-demon war, where Shiraori tries to console Ariel over the goddess' betrayal, and admits that she considers Ariel her grandmother and herself "granny's little girl."
  Shiraori: (Narrating) At the beginning, I was doing all this because D forced me to. However, while I traveled together with the Demon King, she let me eat delicious food, and we chatted together. I’m not sure what I should call this emotion that welled up while doing so. I, out of respect for the Demon King’s purpose, want to grant her wish. Her wish to save the Goddess.
• Bad Guys Do the Dirty Work: In the Web Novel, Hugo is finally killed by Wrath, after Shun refuses to do it. Overlaps with Mercy Kill in that Wrath was disobeying Shiro's orders by doing so, since he didn't want Hugo to have to suffer through being used as a mind-controlled puppet any longer.
• The Bad Guy Wins: Greater-Scope Villain D is beyond the ability of anyone in the cast to even dream of opposing so while the world is just barely saved in the end, a lot of the main and supporting cast have died. Dangerous loose ends Sophia and Dustin are still around and could unleash a vampire apocalypse or religious nuttery respectively. D herself, meanwhile, has captured Shiraori after she failed to fake her own death and intends to keep her as a toy for all eternity, though the latter is still determined to escape.
• Badass Army
  • The Ninth Army of the demons consists of dragons disguised as demons. Needless to say, this makes them far more powerful than the other armies.
  • The Tenth Army isn't as powerful as the Ninth, but working together two of the soldiers could probably take down Shun. Shiraori still thinks of them as cannon fodder.
• Band of Brothers: Due to Shiraori's unique training methods called power leveling, the Tenth Army have close knit bonds with each other with an Undying Loyalty towards Shiraori & by extension Phelmina. With this, Wald has a hard time bonding with them due to the common knowledge of him ruining Phelmina's life before.
• Batter Up!: Shiraori "borrowed" D's all-destroying single-use-only bat to destroy the elf town barrier and start the war.
• Battle Couple: Amongst the Human reincarnations, Tagawa Kunihiko & Kushitani Asaka are known to be one and one ,if not, the most powerful & competent in the consensus of the Demon side reincarnations.
• The Beastmaster: Taming monsters for use in combat is fairly common and it can even extend to humanoid monsters such as goblins. Kumoko was targeted for taming due to her presence disrupting the movement of monsters in the labyrinth. To tame a monster you need to either have it agree to be tamed (unlikely) or beat it into submission. Given that the taming party burned her precious webs and Kumoko herself is stronger than a dragon by that point, neither approach goes terribly well.
• Beast with a Human Face: According to Shun, Reincarnators who started as beasts will gain their humanoid form with their previous life's face during evolution as he observes Fei's evolution. It's also the main reason why he easily identifies Kyouya, now Wrath, and Shiraori, due to having the same face as Wakaba Hiiro, during their meeting at the Battle of the Elf Village.
• Beam-O-War: In the manga, when Kumoko fights Mother, she counters Mother's Breath Weapon with her own and is surprised that she manages to stalemate it.
• Bee Afraid: The poisonous horse-sized Finjegoath and its evolved forms in the Elro Labirynth. While individually they aren't much of a threat, they normally move around in groups with a High Finjegoath as their leader, meaning you need to fight about five at once. They're also extremely aggressive and weirdly good at sneak attacks.
• The Berserker: Activating the Anger, Rage or Wrath skills grants an immense boost in strength but causes a loss of self control. This can be mostly avoided by having Heresy Nullity but seemingly not entirely: Kumoko refuses to use the skill Anger anymore after a single test run.
• Best Served Cold: Hugo doesn't have the faintest clue who Shiraori is thanks to her screwing with his head, but even aside from her rage at him threatening Oka-san she carries a serious grudge against him for wanting to kill her when she was just a normal spider. As a result, she doesn't simply kill him when she gets the chance. No, she turns him into a puppet, strings him along for years and has a very gruesome fate in mind for him, though he dies before she can enact it.
• Better than Sex. Having your blood sucked feels extremely good and is strongly implied to lead to actual sex soon after. Wrath finds this distasteful, especially when Sophia casually propositions him.
• Big Bad Ensemble: As noted by the author, Okina Baba, there are three main "Perpetrators" who are responsible for shaping the events of the story, from the top: Potimas, D and Shiraori.
  • Potimas is the Primary Perpetrator, whose selfish, single-minded pursuit of Immortality is what ultimately started the chain of events that led to the world's current state, including the world being on the brink of destruction and necessity of the System itself, the creation of several of the world's races, the situations (and traumas) of several characters (such as Sensei and Ariel) and even, partially, the deaths of the students at the start of the series! It says a lot that even after finally being killed, his machinations still have an effect on the story. In short, this person took the gun first and shot the backstory full of holes without mercy or guilt.
  • D/Wakaba Hiiro, the Secondary Perpetrator, came into the picture after Potimas's machinations had already left a lasting impact on the backstory. D was responsible for creating the System and binding everything on the world to it, which alone makes her a very important historic figure. However, D also threw in various mechanical quirks and extras into the System that could be said to be unnecessary or even outright dangerous for its purpose simply because it was more interesting that way, which had very detrimental effects over the course of history. She also is responsible for allowing the Primary Perpetrator to run around unchecked in the present because she stopped the one person who could and would have done something about it before they could do anything. Finally, it was D who set up the reincarnators in the new world and bound them to the System, including creating Kumoko's fake identity and self-awareness, making her directly responsible for Shiraori's existence, which makes D indirectly responsible for their actions in the story, including Shiraori's own machinations because she forbid Shiraori from simply leaving the conflict, forcing her instead to actively participate in it. In short, after Potimas was done, this person picked up the gun next, nonchalantly taped it to the hand of the backstory and calmly sat down to watch what happened next. With a tub of popcorn.
  • Shiraori/Kumoko, also known as Shiro, is the Tertiary Perpetrator, the person who, after taking into account the actions of the Primary and Secondary Perpetrators, decided to become the big mover in the present of the story in order to address and attempt to fix the giant mess they left behind. Partly because of her own character flaws and because of her circumstances, the methods she uses and the path she walks have essentially landed her squarely on the role of the Big Bad from a conventional storytelling point, even though she's actually the protagonist. Her web stretches out to cover the known world; her eyes are everywhere, her schemes are in some way woven into the lives or plots of a lot of the other characters, she's the one who holds the real power behind the Demon King, and she's the one who stands the best chance of preventing the destruction of the world and the complete soul collapse of its inhabitants. Cold and aloof, pragmatic nearly to an extreme, but self-conscious and still capable of kindness, worn down by numerous traumas and experiences, the "Evil God" who conspires to save the world through genocide; this person picked up the gun last, and decided to Shoot the Dog in order to put it out of its misery while scorning the previous two individuals for starting and then prolonging it's suffering. That is the kind of person our protagonist is.
• Big Brother Instinct
  • Shun vows to become strong so he can be strong enough to protect his half-sister Sue. Their older brother Julius is very fond of both of them and even increases his training so he can remain somebody they look up to rather than being surpassed.
  • Kyouya loved his goblin family and wanted to protect his younger goblin sister. Buirims first making Kyouya kill and then eat her left him in a blind rage.
• Black Humor: The humor in the story can be rather dark and ranges from jokes about cannibalism to infanticide and how Ariel probably isn't mother (or more accurately grandmother) of the year.
• Blatant Lies: When D is asking people which side they'll pick in the upcoming conflict she ensures that there will be a conflict by lying about what people are trying to do. Namely, she says that Shiraori intends to sacrifice the people in order to save Sariel. The truth is that yeah, a lot of people will die, but the other viable plan is arguably even more dangerous and trying to interfere could make both plans impossible, killing the planet and everyone on it apart from Shiraori and Gyurie. But she doesn't mention that, instead saying that opposing Shiraori will save humanity.
• Blessed with Suck
  • It's possible to pick up skills in-universe that are useless because you don't have the necessary stats or support skills to use them properly. For example, Kumoko took the Detection skill early, but the information overload was so intense she couldn't use it until her information processing skills caught up and she gained Heresy Nullity.
  • The Hero and Demon King titles are very powerful, but they ensure an eternal war between humans and demons. Worse, anyone beaten by the Hero gains the title Subjugated By The Hero, which causes the System to spend a non negligible amount of energy to grant the titles. Plus, if the Hero or Demon King attempt to attack a god, the spell would instantly tap into the MA energy as a fuel source to power up their attack. The one attempt not only drained the MA energy gathered by the planet up to that point, but the spell didn't even work right let alone do the job it was supposed to. It simply misfired and killed the Hero, the Demon King and two dozen innocent children because they didn't know enough magic to fire at someone outside the System.
  • After hanging around in the middle layer hunting for awhile, Kumoko accidentally earns the Fear Bringer title by increasing an enemy's fear resistance. This gives her a passive fear aura that cannot be turned off, which causes monsters to run away from her the moment they notice her and decreases her stealth ability. As a result, hunting becomes significantly more difficult since she can't chase enemies into the magma.
• Bottomless Magazines: The sea urchin-type robot pumps out more bullets than there is room in its body. Shiraori reasons it's using a pocket dimension for this purpose.
• Body Double: Or soul double in this case. Shiraori was created by grafting a portion of D's soul onto the soul of a spider. When it died, the soul would reach the afterlife and confuse D's subordinates regarding her current location.
• Boring, but Practical: When Kumoko is going up against Alaba, it's more or less a stalemate with him having the overall advantage, but unable to win because his most powerful attack is too slow and easy to interrupt while everything else is easy to dodge. Eventually, he comes up with a much better strategy: Shrink the battlefield. Using earth magic to remove her evasive ability and then forcing her into certain positions results in being struck by much weaker but faster brute melee attacks, which have so much mass behind them that even while they deal relatively little damage they're still impossible for a little spider to recover from. Every time she's hit, it sends her flying and interrupts her concentration. Unfortunately for him, it's too little too late: As Kumoko nears death he runs out of energy and collapses.
• Brainwashed: The Lust Skill allows the user to brainwash any victim into obeying them, though it comes undone when the user dies. Hugo used this to control two countries and the Church. It's possible to resist with either high Heresy Resistance (probably) or by being a Ruler as in the case of the Pope, who played along with Hugo due to Shiraori controlling him.
• Brilliant, but Lazy: Ronandt secretly praises Aurel as a brilliant student that can actually surpass Julius with her grasp of Space Magic and laments on her lack of effort & motivation in training.
• Broke Your Arm Punching Out Cthulhu: Ariel managed to destroy Potimas's most powerful anti-god weapon at the cost of cutting her remaining lifespan to one year and leaving her incapable of combat.
• Bullying a Dragon
  • Potimas keeps antagonizing the Gods, even though his first attempt failed spectacularly to the point it caused his world's original apocalypse, unaware he's only lived as long as he did because "D" found it more interesting to tie Gyurie's hands and leave it to humans to kill him. He can't even comprehend what's happening when one of the weakest of the gods, the newly ascended Shiraori, destroys all his armies in a few seconds by herself.
  • In the web novel, when Kumoko shows up on a battlefield intending to help the Goddess religion against the Divine Word religion, she only attacks the latter until a random soldier from 'her' side attacks her in a panic. When she defends herself, the people she was defending view her as hostile and attack, so she ends up massacring both sides.
• Bunny-Ears Lawyer: Amongst the Puppet Taratect sisters, each of which are a step below a Queen Taratect, Fiel is quite a Troll and even screws around Shiraori.
• But for Me, It Was Tuesday: Sophia genuinely can't remember Felmina at all despite numerous assassination and bullying attempts. She actually feels kind of remorseful and hypocritical in that respect because she knows exactly how it feels to not even register in the eyes of someone you resent with all your being. The reason she can't remember is not just because Felmina was never anything approaching an actual threat to her, but also because what they were 'fighting' over was never important to Sophia to begin with: Waldo might be completely inconsequential to her and no more than a thrall that helps justify her own lifestyle at best, but when Felmina starts knowingly competing with Sophia for Shiraori's attention she starts getting taken much more seriously.
• Buxom Beauty Standard
  • Played for laughs. Top and bottom rankings for female bust size are listed at one point, but the #1 spot is occupied by Mother. Well, a spider larger than a whale technically would have a larger chest circumference than any puny humanoid, if you think about it.
  • D basically cursed the reincarnators to not have a larger bust than her, though some have one anyway. Sophia in particular is implied to be perhaps the most attractive or at least up there and has the largest breasts of all. At the opposite end of the spectrum Ariel, Suelecia and Oka-chan are all annoyed because they're completely flat.
• The Cake Is a Lie: Immortality is a skill that can be purchased but the points required is staggeringly high - 100 million. "D" explains that she doesn't expect anyone to ever purchase it - the skill exists simply to give the most powerful something to aim for so that their souls will yield more energy when they die.
• Call a Rabbit a "Smeerp": Shiraori refers to the creatures she makes as her clones, but in reality they're more like little puppet creatures that can be (but usually aren't) granted semi autonomous behavior.
• Call That a Formation?: In the battle between Ohts and Sariella, the two armies just charge at each other en masse with barely any tactics. In the manga version Kumoko even lampshades this.
• Cannot Spit It Out: Shiraori is so shy and anti-social that she is generally incapable of saying more than a few words to other people before just running away, requiring Sophia or Wrath to "translate" for her. In fact, she basically has to activate a fake personality namely a copy of "D" or divert massive amounts of clones to speech assistance just to manage to speak for more than a minute, and goes right back to two to three words per conversation afterwards.
• Cap: The System is a framework designed to help increase strength, but there are limits to how much it will do. Only breaking out of the System will let you exceed those limits, which is a fancier way of saying you need to become a god to uncap your stats and skills.
  • Monsters have level caps that cannot be crossed unless they evolve. However, any monster that has no further evolutions is implied to have uncapped level growth.
  • Skills only go up to level ten. They may evolve into a higher rank at that point, but eventually there comes a point where the skill cannot improve further. Similarly, stats also cap at a point that makes even Ariel inferior to even the weakest of gods.
• Cassandra Truth: Sariel tried to warn the world about the dangers of MA energy, but since she was just a glorified nurse and her warnings were not backed by any kind of meaningful evidence the world simply ignored her. The dragons had a bit more credibility, but everyone hated the dragons for good reason so they were ignored as well.
• Catchphrase: "Nai wa (no way)" for Kumoko and D as well.
• Casting Gag:
  • The original light novel contains a Shout-Out towards Puella Magi Madoka Magica where Kumoko said that she'd accept any strange creatures that offers to make her a magical girl. When the anime is announced, Kumoko's voice actress is revealed to be Madoka's herself.
  • A meta one. Sumire Uesaka gave her voice to Kumoko before in promotional materials. In the series proper, she gives her voice to the Demon Lord, as one another Red Herring for the Kumoko is Ariel theory.
• Celestial Bureaucracy: Unlike the races like dragons and angels who just carve out turf for themselves and fight amongst each other, D and Meido are indicated to have genuinely important responsibilities when it comes to managing the cosmos. Both are implied to be involved in the cycle of reincarnation and the afterlife and D's job actually involves copious amounts of paperwork. Meido apparently sucks at it though because she's so combat focused.
  • The light novel reveals that D is in charge of the underworld, and Meido is in charge of hell.
• Chainmail Bikini: In the ED, a shot of what Kumoko would have wanted to be like if she was reincarnated in another world has her wearing one.
• Charm Person
  • Sophia charmed a large number of male students at the academy so she could feed on them more easily. She did it so casually that thinking back on it makes her a little uncomfortable, realizing that someone with human sensibilities couldn't have done that.
  • In the light novel it's shown that charm spells can be very dangerous: Hugo overdid them occasionally and basically destroyed the targets' minds. They still followed his orders, but without them they wouldn't do anything.
• Childhood Friend Romance: Tagawa Kunihiko & Kushitani Asaka are childhood friends in both their previous world & the new one. Both also think that they'll marry with each other in the previous world and Tagawa took the chance to confess his feelings for her in the new world, in which Asaka accepts.
• The Chosen One: At any given time there will be a "Hero" and "Demon King", automatically selected by the System. The Hero leads humans against the Demon King's demons though at the start of the story both sides are avoiding conflict. A Demon King and Hero, Sariel's assistant Foddway and one of Ariel's experimental siblings respectively, naturally arose soon after the System was established; "D" found it amusing and made it part of the System. Shun seems to be an extra special version because Sariel went out of her way to pick him because she knew Shiraori wasn't willing to kill him. As an added bonus, he has a broken 'everything tends to go the way I want' luck-type skill attached courtesy of D.
• Chuck Cunningham Syndrome: According to the author's notes, originally Shun was going to travel with a young nobleman named Palton and a cranky teacher named Oriza, but this left a gender unbalanced party so both of them simply vanish from the story and are replaced with Katia and Anna respectively.
• Clone Army: Shiraori has an army of small spider clones scattered across the world and pocket dimensions, carrying out missions, spying, researching magic... and making sure that Sophia doesn't get into much trouble. It doesn't work. For the closest thing she has to a super move, she has them peek out of their pocket dimensions all at once to all cast energy draining Evil Eye of Grudge at once, rapidly deteriorating the strength of her enemy.
• Cloning Gambit:
  • Potimas puts a piece of his soul into a target and then uses it to take them over, using the new body as a disposable piece to be moved around. When they're overpowered or captured, he has them commit suicide immediately.
  • "D" tries one as a joke by grafting a sliver of her soul onto Kumoko's original soul to transfer the relevant memories of her "death" at the hands of the previous Hero and Demon King. "D" hoped her decoy's presence would confuse the other gods for a few days once it died and its soul ended up in the afterlife, giving her some more time to mess around on Earth. Though she quickly abandons that plan after Kumoko manages to survive and prove to be infinitely more entertaining.
• Compressed Adaptation
  • Volume five of the light novel adapts the war with the elves from Shun's perspective, Kumoko's time in Sariela and the beginning of her partnership with Ariel, but on top of rearranging events such as when Kumoko and Ariel partner up it also cuts down on a lot of the character building scenes and change some events to take a lot less time. For example, Sophia's POV is completely absent, the war event and Ariel's attack are mixed together, the egg revival is taken care of within a few pages as opposed to several chapters. This last point almost entirely skips over the origin of the Remnants of the Nightmare.
  • Volume six does however bring the Remnants back to the forefront, with their raw power explained by them not just being "talented" as in the web novel, but also due to Kumoko's rogue parallel wills training them in order to destroy humanity.
  • The anime blows past many scenes that took a great deal of time to deal with in other mediums. For example!
    • Kumoko's most vulnerable moment in the entire story is when she's on the verge of death and in agony for about a week after being stung by a giant wasp. She then tries to climb back to safety after recovering from this injury, only to be traumatized by Alaba. This entire sequence of events is completely absent from the anime apart from Alaba's introduction where it kills some snakes.
    • Many scenes on the human-side/ non-Komoko-side are either compressed or removed entirely. Every human side chapter in light novel version 1 is omitted, and the start of the human side is presented as the academy entrance ceremony, which is rewritten to be about introducing all the non-elf-village reincarnators at once instead of just Hugo and Yuri. A lot of world building is cut out as well, which leaves Shun and his party looking flat, generic and stupid in their scenes, which is not the case in the light novel.
• Condescending Compassion: Angels are probably defense mechanisms produced by planets themselves to defend against the gods that threaten them and the universe as a whole. Their mission is to protect 'primitive lifeforms,' which indicates how much genuine compassion they normally have.
• Convection, Schmonvection: Averted. The middle layer of the Labyrinth is filled with lava and can be traversed but the heat is enough to cause constant damage. Kumoko has to spend a lot of time acquiring and improving a resistance skill to survive in there. Human adventurers usually avoid the level for this reason.
• Crapsack World: Most of the world is populated by hostile monsters who can only be confronted in groups and the seas cannot be used for any reason due to the overwhelming number of water dragons. The Humans and Demons are either in a state of open or cold war at all times while the two major religions try to destroy each other despite worshiping the same deity. Worse yet is that the entire skill system is powered by recycling the energy of souls, which will eventually cause the souls to break apart. Constant war and monster hunting is necessary to sustain the world's recovery; peace could doom the entire world. And why is all of that necessary? Because more than half of the planet is dead, shattered rock. The System was repairing that until the previous Hero and Demon King wrecked the energy reserves.
• Creepy Centipedes: The Elro Ferect are human-sized ones. With a paralytic poison. And they Zerg Rush.
• Crippling Overspecialization: Meido is the strongest named character in the story, well above even D in power. However, combat is apparently all she's good at, so her subordinates try to keep her busy so she doesn't get in the way.
• Cruel and Unusual Death:
  • In the manga once Kumoko gains space magic she notes how long it takes to make work and how opponents will likely move to avoid it. She determines the best use of it would be to attack enemies internally and tests this out by using it on a bandits brain. An image of a Rubik's cube being twisted around is shown to suggest what she's doing to the actual organ followed by a pixelated image and a horrified Kumoko.
  • In Volume 12, Yaana is killed being crushed into paste by a Queen Taratect's leg after saving Julius, pushing him out of harm's way, when Shiraori summoned it in the Human Demon War.
• Cryptic Conversation:
  • The Remnants give the B-team a vague warning about what's coming, instead of actually answering Shun's questions. Even Shiraori has no clue what they were talking about, but they're not really capable of answering her questions.
  • Any conversation between Demon Lord Ariel, "Kuro" and "Shiro-Chan", which gives vague details about the overarching plot without actually explaining what it is.
  • Conversations between Kumoko and the Administrators after she hits Taboo Lv 10, as Taboo has given her complete understanding of what the Administrators and the System are for, and thus she has no need to explain them to herself.
• Curb-Stomp Battle:
  • In the manga, the Fire Dragon Rend faces off against the Queen Taratect with a massive army of wyrms. The Queen Taratect casually obliterates them with a blast of her Dragon Breath, leaving Rend severely injured in the process... and it's later shown she was holding back as her Dragon Breath is powerful enough to blast a massive hole clean through from the bottom layer of the Labyrinth to the surface.
  • After leaving the Elro Labyrinth, Kumoko utterly decimates humans whenever she meets them. She's actually embarrassed when she accidentally destroys an entire fort and everyone inside with a few simple magical attacks. Her strength eventually reaches to the point where Dustin mentions in volume 7 that only a select few can actually beat her, one of them being Ariel, and that is even prior to her apotheosis.
  • Ariel, as the strongest being in the system, utterly decimates anyone who stands in her path that only the Administrators and the one having the Hero title is capable of stopping her.
  • Gyurie delivers a completely one-sided beatdown to Wrath, both to make him regain his sanity and to vent his anger.
  • Happened in the distant past when the dragons decided to exterminate the ancient civilization. All of the civilization's weapons could only barely slow the dragons as entire cities were obliterated.
• Cute Little Fangs:
  • These are part of Kumoko's character design from her perspective. From the humans' perspective, we see that they are actually chelicerae.
  • Ariel and Sophia both show these at times due to their natures as Origin Taratect and vampire respectively.
• Cyborg: One of Potimas' more powerful avatars is a brain encased in a magically-enhanced mechanical body.
• Dangerous Drowsiness: Kumoko gets half of her body bitten off while battling a swarm of monstrous apes. As her HP starts dropping, she feels drowsy and is tempted to fall asleep, but fights it off because she knows that if she does, she'll die.
• Dangerous Forbidden Technique:
  • The Ruler Titles/Skills are all extremely powerful, but also directly affect the soul of the user at a fundamental level.
    • Pride is considered the most dangerous as it causes explosive growth but causes such radical changes over time that the soul quickly collapses under the strain.
    • Humility is also portrayed as being particularly bad because it uses the user's soul as fuel for a massive temporary powerup.
  • Parallel Wills basically puts another you inside your body when it's active, which means you can devote your full attention to multiple things at the same time. However, there's a catch: All of them are you, but also distinct, which causes major disassociation problems as time goes on. When exactly Kumoko figured this out is unclear, but she did notice the problem and stop using them this way as much as possible. However, they do still prove useful when moved outside her body to linked souls, such as the Queen Taratect. In this way they can gain pseudo independence while also firmly establishing the original Kumoko personality as dominant. However, she becomes a god not long after and it becomes irrelevant. It's also indicated that creating too many independent Parallel Wills can cause the soul to collapse due to being split too many times. As her skill level rises, she eventually stops making new copies and instead makes tiny non sentient drones that simply help her processing ability.
  • Heresy Magic directly attacks the target's soul, causing damage and possibly destroying it outright. Even Kumoko during her berserk fit disdains its use. Abyss Magic has a similar overall effect because creatures killed by it have their souls fed back into the System as fuel, preventing reincarnation and effectively being cessation of existence.
  • Corrosion magic is the magic of death itself. It's essentially a save or die attack kept balanced by also generally affecting the wielder as well, especially with the touch radius Corrosion Attack. These attacks are why no spider monster has ever reached Zana Horowa: The two evolutions preceding it both have powerful corrosion attacks that kill them before they can reach that stage. Shiraori, however, is not bound to this limitation and vaporizes Hero Julius with a single glance.
  • Detection and Appraisal both feed information into the soul directly. Appraisal's demerits can be limited by high affinity with the skill, but Detection is all but unusable as a result: So much information is fed into the soul that they actually overload and damage it, requiring multiple skills running in the background to help compensate. Appraisal also has another drawback in that the target can actually feel that they're being appraised, which is taken as being rude at best in polite society and a sign of hostility everywhere else, which is why monsters keep attacking Kumoko.
• David Versus Goliath
  • Any time Kumoko has to fight a dragon. Not only are the dragons much stronger than her, they're also enormous in comparison as she avoided the larger adult forms. However, after Alaba, by the next time she goes up against a dragon she's already an arachne and stronger than a Queen Taratect, meaning she can literally punch three adult dragons to death just to see how her physical abilities have improved.
  • While Shiraori and Gyurie are vaguely allied, she's been making a lot of plans in case he turns hostile towards her for whatever reason. While she's the bottom of the bottom tier and he's lower mid ranked and far more experienced, she thinks she might have about a 20% chance of victory already, but only if he can't counter her trump guard. It turns out the relationship between them actually went in the other direction: Gyurie had no chance of victory and knew it.
• D-Cup Distress: One of Aurel's problems with regards to relationships is because she has a complex on her large chest that even Julius, as pure-hearted as he is, always takes a glance on it whenever they meet, earning Yaana's ire towards her.
• Deader than Dead: There are three ways of killing someone so thoroughly they can never come back, bypassing all forms of immortality. Two are intentional while the third is the essential conflict of the latter half of the story.
  • The Heresy element attacks the soul with either really unpleasant status effects. The offensive spells are the most useful in battles between gods because they disrupt the soul's container and cause the entire thing to collapse, which makes it incapable of reincarnation and bypasses any kind of immortality and healing factor: It doesn't matter if your body is still alive if your soul is gone.
  • Abyss Magic banishes the victim's soul from the System and into the MA realm, where it is absorbed into the world's energy store. This allows it to bypass system protections such as Immortality.
  • Souls can collapse if split into too many parts with skills like Parallel Wills or damaged by Presenting skills; even a being with Immortality will die. The souls native to the world are also eroding due to constant reincarnation with no chance to recover. Many people have already dropped out of the System because their souls can no longer take it and a critical threshold is coming in the relatively close future where too many collapses will cause the whole System to fail and destroy the planet.
• Deadly Gaze: Kumoko has fun learning various eye related powers as a kind of collection, especially since you can activate as many of them as you have eyes. Since she has eight eyes, she can fire up to eight different kinds of magic eyes at once. Some of them rob stamina, health and magic, some cause paralysis, some inflict damage directly and so on. Many years later, Shiraori uses a different kind of eye attack to instantly turn Julius to dust.
• Death of a Thousand Cuts: What Kumoko faces when cornered between a group of Arch Taratects and a Puppet Taratect. While they lack the strength to kill her in one blow, they can chip away at her body and stats over time.
• Deal with the Devil: Discussed. In the backstory, Gyurie knew from the start that seeking out D to save Sariel while still granting her wish of saving their planet was equivalent to offering himself, Sariel and their entire world up to be D's playthings, but still decided to go through with it as he had no alternatives. D also outright admits this when she gets Sariel to agree to become the nexus of the System.
  D: Now then, with my self-introduction out of the way, let us proceed to the negotiation. Dispensing with the small-talk, I shall plainly state my business: Please come play with me.
• Decapitated Army: Happens frequently during the war when the death of a general, either demon or human, causes their army to collapse in disarray. Justified given they are usually the strongest member of their army, meaning their killer can overwhelm the rest of the army easily.
• Deconstructor Fleet: While the story starts off as just a twist on the reincarnation genre, as the narrative progresses it begins to show signs of this towards aspects of the genre and other tropes as well.
  • Everything tries to kill Kumoko in the Labyrinth which seems par for the course. Much later she learns they could feel her using Appraisal and perceived it as an attack or a prelude to one. There's no telling how many fights she was in were actually instigated by her gamer's instinct.
  • While Shun is your classic isekai hero, he is absolutely not the protagonist. Kumoko is, and her actions shape the plot such that the author considers her the third most important person in shaping the world into what it is behind only Potimas and D. The story is also subtly critical of his moral positions and the ease with which he gets through things since the world is literally built to make him a born winner. But... that doesn't necessarily mean that he's wrong.
  • Kumoko herself seems like a classic Gamer Chick hikikomori, the latter of which comes across as mostly an Informed Attribute thanks to the lack of other characters to interact with. Unfortunately, once there are other people to talk to it turns out she's more like an actual hikikomori, social phobias and all. It takes ages for her to actually be able to say more than one or two words at a time and she suffers intense anxiety around most people. She can talk normally to one person, Ariel, but that's kind of cheating given that it's noted that Ariel is basically half her at this point, so it's almost like she's talking to herself.
  • The RPG mechanics incline everyone towards fighting and the spread of monsters has crippled many aspects of civilization. This is on top of skills being unnatural modifications to the soul and XP being derived from an enemy's soul.
  • Oka-chan is apparently a happy Sensei-chan but her chapter reveals she's deeply conflicted about her personality, hobbies, and the resulting lack of credibility. Faced with the inability to protect all of her students she desperately wants support but can't ask due to her position.
  • Telling a villain to Go and Sin No More only works if they acknowledge their shortcomings and want to reform. Otherwise a Cruel Mercy will just make them want revenge.
  • Sophia lives out an otome game, building a reverse harem at a noble academy, but only succeeds at it because she was literally mind controlling the other students. When she's forced to acknowledge what she's doing most of the people interested in her disappear with only two of them explicitly still trying to stay with her. The more important of the two, Waldo, is considered to be pathetic for staying with her anyway. She's also a dark variant of the "Villainess" type of reincarnation; whereas most of her type try to live a good life and reform in order to avoid being seen as a villain, her efforts to live a good life unwittingly turn her into one in the eyes of the public.
  • Wrath goes through the monster rebirth genre similar to Kumoko, but is incredibly scarred by the entire affair due to being treated as less than human while also seeing how good and noble the goblins could be.
  • Being an Idiot Hero who doesn't follow the rules and does whatever they want will only kill those around them. Being an All-Loving Hero, trying to save everyone, will let dangerous people escape and/or bring more harm, making the job of those trying to make the world more stable even more difficult.
  • Isekailand having an RPG type skill system that powers up the characters is something of a stock trope in modern isekai, but all the characters consider it strange and unnatural rather than blindly accept it as is the standard. Shiraori's plan is to dismantle the System that grants such skills to people as it's extremely dangerous: Power doesn't come from nowhere, meaning your soul is slightly damaged every time you gain new powers. Skills should not exist.
• Deliberate Injury Gambit: After evolving into an Arachne, Kumoko has a human and spider head which would need to be destroyed at the same time to incapacitate her. Fighting Potimas, she deliberately allows him to destroy her human head. He momentarily lowers his guard, giving Kumoko time to land a blow.
• De-power: The Presentation skill converts all of its users skills and titles into energy which are then "presented" to the Goddess. This is usually a voluntary sacrifice by the faithful but Oka-chan manages to use it to de-power Hugo. When it is seen from Shiraori's perspective, she says that Oka's soul almost collapsed. It's implied that Presentation was originally developed as a suicide technique for those who could not stand to live in what is basically purgatory, though the world at large has forgotten what the world was like before the System was put in place.
• Did You Just Flip Off Cthulhu?
  • Kumoko at one point sets up what amounts to a healing shrine both to get free cake and to have an excuse to stay near Sophia and keep an eye on her. While she's there she would regularly get rude visitors making demands of the terrifying spider monster that was behaving itself but was still clearly an extremely dangerous monster. The only reason she didn't kill these kinds of arrogant idiots is because she was enjoying her good reputation (and being given good food by the villagers) until one finally crossed the line and actually tried attacking her.
  • Specifically averted when going in the other direction. When speaking to perceives superiors she's always as polite and accommodating as possible even though the individuals involved probably wouldn't do anything no matter how rude she gets. After all, there's always a chance that she's wrong and D/Gyurie might squish her for real.
• Didn't Think This Through
  • After gaining limited gravity powers, Kumoko tries to train up her muscles by using them on herself. Not only does this not work, it actually slows down her physical improvement because she's just making herself work harder to get the same results.
  • As Kumoko notes after shoring up her defenses, it actually doesn't matter much once a significantly larger opponent hits her because she'll still be sent flying. Indeed, she's nearly killed once Alaba skips the big fancy moves and simply shrinks the battleground down then charges in to repeatedly melee her.
• Died Standing Up: Combined with The Last Dance; Agner, despite accepting his fate of dying towards a queen taratect, still managed to give trouble towards the Hero's party and actually costs Julius the demise of both Jeskan & Hawkin.
• Difficult, but Awesome
  • The Appraisal skill is worthless at low levels and only returns information like 'rock' or 'bat' when you try to look at things. It also causes headaches as the ability gets more powerful. As such, it can only really be used either by people with great affinity for the skill or through use of a magic item that lets the user ignore the burden.
  • Detection includes numerous powerful skills within it including the ability to detect magic, nearby enemies and so on. However, the information is so overwhelming it literally functions as an attack on your own soul. As a result it's not just next to unusable, but also makes it impossible to detect things like magic normally. To use Detection, you need to have high level mental skills to handle the information overload, Heresy Resistance/Nullity or both. Once you do, though, the amount of information gained through a quick glance is staggering.
  • The main weapons of gods are heresy and space magic, which are apparently the most difficult types of magic out there. Heresy magic in particular is so difficult that it's still beyond Shiraori despite her noted genius aptitude for magic and using thousands of clones to research it among the other tasks she assigns them.
• Discard and Draw:
  • When Kumoko leaves the System to become a god, she loses her poison abilities, most of her resistances, most of her other magic abilities, Appraisal and several other useful skills that don't exist outside the System. On the other hand, the abilities she keeps, namely her physical abilities, Evil Eyes, thread, dark magic and space magic, are all massively improved. For example, she maybe jokingly maybe seriously indicates that to break her thread through sheer force would require planet buster level attacks. She also gains the ability to create thousands of semi autonomous clones to explore, spy, fight, serve as backup bodies and fulfill preprogrammed instructions like teleporting her to safely immediately if she becomes incapacitated somehow.
  • When an Anogratch evolves into its Bagragratch form, it becomes exponentially stronger and more durable. However it also loses its original form's Vengeance and Wrath skills, resulting in it actually being considered less of a threat compared to a horde of angry Anogratch.
• "Do It Yourself" Theme Tune: The Ending Themes for the anime, "Do Your Best! Kumoko-san's Theme" and "Reality Assault Hierarchy", are sung by Kumoko's Voice Actress in character as she laments her current situation.
• Does This Remind You of Anything?
  • When Wrath first sees Shiraori drunk the description of her assault on Sophia sounds more like she's being molested than about to be eaten.
  • The way Shiraori asks for favors is a little... open to interpretation:
    Shiraori: I picked up a man. I want to put him up at the mansion.
    Blow: Wh-what the fuck!?
• Don't Try This at Home: Early in the story Kumoko boasts about her former financial independence. She says she gambled on the stock market, and never talked to anyone or spoke her family, which she claims is the height of achievement and joy. Immediately after this the chapter ends and the author has a warning not to actually try this.
• Doomed Hometown: Sophia and Wrath both have their hometowns destroyed within years of their birth, leaving them the sole survivors of their families. Especially tragic for Wrath who had come to deeply love his family and the village itself. Sophia, on the other hand, didn't have time to come to view her new parents as really being her parents and is thus not that affected by their deaths.
• Doomsday Device: The G-fleet bomb, in which D had to relocate Kumoko to save the planet from explosion when Kumoko consumes it.
• Double Jump: The Space Maneuver skill allows this by temporarily creating footing wherever needed. Technically, the invisible footing can be made to stay in the air for as long as the wielder continues fueling it, but the cost of doing so rises exponentially, which Kumoko uses to gimmick an Arch Taratect to death by teleporting it above a magma lake, forcing it to create a platform to stand on or burn to death. It runs out of stamina and dies.
• Dramatically Missing the Point: When Wrath hears Dustin explain his utilitarian philosophy, he's shaken by the pope's conviction. He reinterprets his words about not meaninglessly piling up bodies as instead something more like a Sunk Cost Fallacy in that he'll try to aim towards a goal that lets him give meaning to the deaths he's already caused. So he accepts Shiraori's plan to save the world even though it might actually be the worse plan because he needs to have some way to forgive himself at least a little.
• Dreadful Musician: Not a musician per se but Riel, being the airhead she is, is so tone deaf that when she was tasked to ring a bell when Wrath wakes up, she rings the bell unsteadily that Wrath mentally complains that it's stress inducing and Sophia angrily tells Riel that it drives her mad.
• Drowning My Sorrows: Unable to deal with the stress of what Shiraori is planning for the demon race but still respecting her and knowing she has absolutely no way to stop her, Felmina has to get dead drunk just to get by.
• Dumb Muscle: Amongst the Puppet Taratects, Sael is often assigned as a bodyguard of the known characters in the story because she's so timid & Literal-Minded that, unless she's given very specific orders, she won't do anything nor think things through which oftens worries both Ariel and Shiraori.
• Dungeon Bypass: Mother is so large that she can't fit through any of the Labyrinth's exits. As such when she needs to chase Kumoko, she uses her breath attack to blast a hole from the deepest layer all the way to the surface, making an exit for herself.
• Dying Race: The Demons are facing a depressed birthrate which, in addition to their perpetual war with humans and the threat of monsters, puts them in serious danger of dying out. The accumulated damage to their souls from the System means less are able to successfully reincarnate.
• Dysfunction Junction: Much of the cast has some kind of mental illness, personality disorder or other significant mental problem. Many of them are even recognizable as real things people commonly face in the real world as well. Shun is one of the very few prominent exceptions, which is probably why he's The Hero.
  • Shiraori suffers from intense anxiety and depression at the very least. She also likely has PTSD and possibly autism. She's nearly paralyzed with anxiety when meeting people, especially when they're people she doesn't know, impatient or there are a lot of them.
  • Wrath is suicidal due to guilt. He also has some serious anger issues that he suppresses to the point of being functional, but stress can make him lash out. He's committed himself to a very questionable course of action as a result.
  • Sophia has very poor self esteem, alienation and feelings of abandonment. She generally feels unloved, unwanted and like she doesn't have a place. That's not even touching on the vampire stuff.
  • Ariel has such an intense hatred for the world that most people who meet her are damn near shitting bricks out of fear.
  • Dustin is noted to be practically a robot in his obsessive pursuit of the greater good. He and Merazofis consider each other nuts because Mera has the same issue of treating Sophia as an emotional crutch.
  • Oka-chan has massive feelings of guilt, inferiority and anxiety which completely blows up when it shows what little faith she had in Potimas was very misplaced. Even before the plot got started with her and everyone else dying she acted like a silly anime character so her students wouldn't hate her. She clings to being a teacher as a way to cope with the situation even nearly twenty years later.
  • "D" is flat out a sociopath who toys with mortal and divine lines out of sheer entertainment. Potimas is a different flavor of sociopath on top of being an unchecked paranoid megalomaniac.
  • Sue is a yandere with an obsessive love for her brother, which he finds squicky when he acknowledges it, and feels alienated from the rest of their family due to their absence while growing up.
  • Katia was originally a closeted gay boy with a secret crush on his best friend, Shun. After reincarnating as a girl she suffers from gender identity issues well into her teen years. When she fully embraces her female identity, she overcorrects on her attraction to Shun and becomes aggressive in her pursuit of him.
  • Hugo is a delusional megalomaniac or at least appears to be. He's actually deluded himself into believing the world is just a dream and is acting out due to feelings of isolation and jealousy of Shun's friends.
  • Whether Sariel can be considered mentally abnormal really depends on what standards you use to judge her, but by human standards she has extremely poorly developed emotions and a weak ego. Her decision making tends to be very flawed and unhelpful as a result.
  • Finally, Gyurie's behavior resembles aboulomania: He finds it next to impossible to make any meaningful decisions and has issues with stress and depression as a result.
• Early Game Hell: Kumiko starts her reincarnation as one of the weakest creatures at the bottom of the labyrinth with only her Speed Stat having any use. She nearly gets killed and eaten by her own mother. However after awhile of training and fighting other monsters she is able to take on armies of monsters single handedly.
• Eats Babies
  • Shiraori thinks that babies, with their soft, plump features, look delicious. She normally keeps her interest in eating a toddler Sophia in check but her drunken self really wants to test the flavor. Over the course of several years her drunken self escalates from licking to nibbling to biting to actually eating pieces.
  • Mother greeted her newborn hatchlings by skewering and eating them like popcorn. After learning how to spawn Kumoko considered following in Mother's footsteps before deciding the hatchlings could just bring her some of their prey.
• Effective Knockoff: Shiraori is actually powerful enough to make clones that transforms into a Queen Taratect — albeit a lesser copy than the ones Ariel have, but still powerful enough to cause massive damage to both the Demon and Human Army, and cost Julius an almost-total annihilation of his party in order to subjugate it in volume 12.
• Elemental Powers: There are magic types for earth, wind, fire, water, ice, lightning, light, dark, poison and heresy, the last of which is basically illusions, Mind Rape and soul attacks. Everyone also has affinity level for each attribute, such as Kumoko being really good with dark and earth while Shun is good with light and water. It's later indicated that most of these magics don't exist outside the system, or at least not in their current forms. Only dark is completely unaltered because it's the special domain of D.
• Elite Mook: Shiraori's tenth army soldiers are nothing special when seen through her eyes, but each of them has average stats of at least a thousand. She estimates that two of them working together would be enough to give Shun some serious trouble. In the light novel this is actually shown with a sandbagging Sophia, Felmina and a normal mook casually wrecking Shun's party until Feirune comes to save them.
  • Shiraori, during her meeting with the other reincarnators after the Battle of the Elf Village, mentions that even her regular rank & file soldiers is enough to deal with Shun alone.
• Enemy Mine: Lampshaded in Volume 7. When Ariel's party stumble upon the ruins of the ancient civilization and accidentally activated it, it took the combined forces of Ariel, Kumoko, Dustin, Potimas and Gyurie to take down said weaponries and the series of events has Kumoko's apotheosis into Shiraori.
• Energy Absorption: Shiraori has two natural talents of her own. The first is dimension magic, which is basically teleporting and making new dimensions and stuff. The second is that she can absorb energy very easily seemingly no matter the source which allows her to simply devour a fragment of MA energy straight from the planet and complete her apotheosis. Taking advantage of this, she gets a lot of use out of the ability to drain energy just by looking at things with her Evil Eye ability. This is particularly useful against Potimas' robots, which have special magical barriers. Yeah, she could brute force them but that would be slow, costly and use up an annoying amount of energy. So why not just eat their energy and beat them like that while at the same time buffing herself?
• Enforced Plug: Played for Laughs; In episode 19, when Sophia meets Potimas for the first time, she overhears Potimas saying to be wary against Kumoko and, by extension, Ariel. Sophia confuses Ariel as a name of a laundry detergent.
• Entertainingly Wrong
  • While Kumoko is dealing with bandits and the elves trying to kidnap Sophia in Keren County, both Potimas and Dustin assume that Ariel is influencing the "Nightmare of the Labyrinth" it to interfere in their operations. They're not entirely wrong, since Ariel gibbing Kumoko is the reason she ended up drifting into Keren County to begin with, but Kumoko is operating entirely independently and for her own reasons.
  • Shiraori is a powerhouse but is avoiding open conflict to conserve energy and fool Potimas; her main display of ability is free use of the rare Transfer magic. Potimas and most Demons assume she is a covert ops specialist with no combat ability, having spent all of her Skill points to acquire Transfer.
  • Balto is wary of Kuro and Shiro because he can tell they aren't normal, but assumes that they must be Rulers. Most people don't even know what Rulers are and this isn't a bad guess given that Shiro held five Ruler titles with Pride, Patience, Sloth, Charity and the new sort of Ruler title of Lord of Wisdom but they are in fact something much worse from his perspective: Both of them are outright gods.
• Escape Battle Technique: Transfer allows the user to teleport from one location to another; the more skilled the user, the faster and more efficient it is for escaping. However, the Demon King skill blocks transfers within a certain radius of the wielder and particularly skilled users of space magic can interfere with others attempts to teleport near them under at least some circumstances.
• Ethnicity Monarch:
  • Queen Taratects are the queen (and Monster Progenitor) of all Taratect monsters.
  • The Demon Lord is the ruler of all demonkind, regardless of whether they agree with the person appointed to be or not.
• Evil Cannot Comprehend Good: Shiraori adores Oka-san and works to keep the reincarnators alive seemingly mostly because Oka-san is struggling to keep them safe, but doesn't seem to understand that just because Hugo probably needs to die doesn't mean that his teacher actually wants him dead, even with all he did to her. She's actually heartbroken about it. So it's probably for the best that Wrath gave him a quick, painless beheading before Shiraori could capture him and turn him over to her expecting that she would want to torture him in revenge.
• Evolutionary Levels: Monsters can evolve into stronger types of monsters if they fulfill certain requirements (usually reaching a certain level in the current form). The level counter goes back to 1 afterwards. Lower-rank species evolve at 10 but the number goes up for higher-rank species. It's speculated humans could evolve at level 100 but nobody has lived long enough to get there.
• Evolving Credits: The anime's Title Sequence changes slightly each time Kumoko evolves into a new form, with the rotating view of Kumoko at the beginning showing her current form.
• Exactly What It Says on the Tin: Shadow magic deals specifically with shadows. Not darkness like you might think, but shadows. This means the offensive applications are all but nonexistent and even its worth as a support magic system is negligible.
• Expendable Clone: Shiraori's clones are treated as little more than tools, since each one is just an extension of her own will. As such she's more annoyed than anything by Julius being good at killing them.
• Expository Theme Tune: Pushed to the Logical Extreme with the ending theme in the anime, "Do Your Best! Kumoko-san's Theme". It starts with Kumoko (with her parallel minds as backup singers) singing about her story as an ordinary high school student in literature class, who after a sudden explosion found herself turned into a weakling spider monster, trapped in a labyrinth with all manner of danger, and crappy food, and people burning her house. She then goes over the fact she wanted to Reincarnate in Another World as a Magical Girl... and then starts asking why the hell isn't there a reincarnation skill, and goes through a dozen of her major skills over the story, including the likes of Heretic Magic and Parallel Minds. The song finally devolves into Kumoko ranting at D about how she refuses to die, how she's going to do whatever it takes to survive, that this is a piece of crap game, how her starting area is way too brutal, how when you Reincarnate in Another World you're supposed to have a fun (human) life, and how she doesn't remember agreeing to any of this so why is she a spider!? All of this in 90 seconds.
• Eye Scream: Hugo controls three people precious to Shun into shoving needles through their eyes and into their brains while Shun watches.
• Failure Is the Only Option: The expedition sent to try taming Kumoko was doomed from the start. Even if she hadn't been in an especially ugly mood after reaching Taboo 10 and even if they had left her nest alone, she was already a Ruler. Apart from the titles and other benefits, Rulers appear to be immune to many mind altering effects such as taming, as shown with Wrath.
• Failure-to-Save Murder: Played with. Shiraori is resented by the demon higher ups for allowing Blow to be killed by Hero Julius when she could have easily saved his life. However, she thought she was doing what he wanted and his own brother grudgingly believes that it's not really her fault. She could have saved him, but the one who actually dealt the killing blow was Julius.
• Fake Memories: Kumoko's memories of life as a human are entirely fabricated and frequently lacking information like the faces of her supposed parents. They're mostly given to her by D so they tend to be realish, but probably for shits and giggles D also gave her memories that would damage her self esteem, such as remembering herself as skinny, unhealthy, ugly and unpopular when everyone thought Wakaba Hiiro aka D was really hot.
• Faking the Dead: During her second encounter with Alaba, Kumoko's nest is destroyed with one attack and she ends up getting covered by rubble. She plays dead until he leaves, though she realizes later that he surely knew she was still alive and simply didn't find her worth killing. After being dubbed the Nightmare she also fakes her death twice, though not on purpose either time. The second time doesn't really fool the people who have seen her before. No way someone that powerful goes down that easy.
• False Utopia: The country of interstice is a place where nobody fights, there are no hostile monsters, and humans and demons live in harmony. Wrath destroys the country, sending the few survivors fleeing into the rest of the world, but even before that it was really a preserve for souls on the verge of collapse. This didn't actually help the people there at all from their fundamental issues, it mostly just served as a way for Gyurie to feel like he was doing something.
• Fantastic Racism:
  • Humans and Demons are physically identical and capable of co-existing. Despite this the two races are constantly at war or under uneasy ceasefire while rebuilding. In the backstory, their hatred originated from Demons being humans who used MA energy to evolve. After the ancient civilization's collapse, Humans began to ostracize and ultimately attack the Demons.
    • The Divine Word religion higher ups know what demons actually are, but are noted to be all about ensuring the survival of humanity even though demons basically are just humans. Even in the event that the System goes down, the plan seems to be to wipe out the demons afterward.
    • The Goddess religion also hates the demons, which disappoints those who are familiar with their origins. Sariel does not distinguish between humans and demons, loving both equally, but the religion that worships her thinks it would be a better idea to work with monsters to wipe out demons than the opposite.
  • There are other intelligent races besides the demons and humans, but the only ones to get any focus are the goblins. They're aggressive towards humanity, but only as a matter of biological necessity to be able to form anything even remotely like a social structure and culture: They only live for about ten years unless they evolve, but to evolve they need to kill and gain experience. Humans wipe them out without a second thought and have next to no awareness that goblins aren't really monsters. It's also indicated that other 'demi-human' races or individuals show up in the populated human areas sometimes but they're implied to have very little success actually fitting in.
• Fate Worse than Death: Just dying isn't really so terrible since the soul will simply reincarnate elsewhere. However, powerful Heresy attacks, dividing up the soul's power and being forced to reincarnate too often over a short period cause damage to the soul and can make it collapse entirely. Shiraori's plan for the world is attempting to limit the reincarnation damage by destroying the System and allowing the souls trapped within to reincarnate normally. However, this requires the immediate price of both killing a lot of people, which isn't a big deal, to causing some short term soul collapse damage among those who have a lot of skills when the System goes down. That one is a major issue because while it's less destructive than the alternative, it's still difficult to accept.
• Fighting from the Inside:
  • When brainwashed by Hugo, Katia developed Parallel Will with her female side falling under Hugo's sway and her male side staying separate. The last act of the male personality was to interfere with the spell on his female side, breaking the brainwashing.
  • Demon Lord Ariel does the same when one of Kumoko's parallel wills tries to absorb her soul. This results in her merging with the fragment, rather than being taken over. She is a lot happier now.
• Five-Man Band
  • The Leader: Shun is the de facto leader of the group as the most charismatic individual and is typically the one to decide on the basic course of action after weighing the opions.
  • The Big Guy: Hyrinth is the most physically solid of the group and an actual adult. He plays the part of the party tank as a result, though he's at risk of falling behind as he already more or less reached his peak.
  • The Smart Guy: Oka usually knows more about what's going on than anyone, but because she doesn't speak of it much she tends to earn some distrust. She's often the one to suggest the next most reasonable goal or how to achieve it while Shun weighs her advice.
  • The Lancer: Typically Katia. While Shun is a straight up magic swordsman, Katia is more of a pure caster type. While Shun is very straightforwardly heroic, Katia is much more pragmatic and willing to make sacrifices, even at her own expense. Notably, she quickly accepts that her parents cannot be saved. She also has the closest relationship with Shun, though he seems to be deliberately ignoring that she's not his male best friend anymore and doesn't view their relationship the same way.
  • The Load: Anna. Which she started stronger than Shun, she already peaked long ago and can't keep up with the group. As a result she can't pull her own weight and she knows it. Shun checks in with her regularly to keep up a reasonable pace and make sure the group stays focused, though to her own lacking self-esteem she tends to be hampered from directly contribuing to the mood.
• Flash Forward: All the side chapters are actually happening considerably later than the events on Kumoko's side of things. As "D" reveals, due to becoming a simple monster, Kumoko was actually able to be reincarnated 6 months before the rest of the class and grew significantly faster.
• Foil:
  • Shiro and D. While Shiro is a heavily flawed character who struggles to do the right thing even when she tries and is in a sense the 'villain' of the story, D is much worse. They share the same basic flaws, but while Shiro is at least trying to think of the people around her and her natural impulses do incline her towards helpful and kind behavior. D, meanwhile is worse than her in every aspect She's lazier, less empathic and straight up sadistic, more arrogant and much more selfish with refusing to share what she has.
  • Shun and Wrath have a virtue and sin that in classical theology oppose each other: Kindness and, well, Wrath. While both are trying to do the right thing, Shun is far more willing to show mercy and look for optimum solutions. Wrath, meanwhile, has noticed that violence solves a lot of problems, at least in the short term. As you can expect, this puts a strain on their friendship and the two end up fighting to the death. Shun ends up winning because he supports the people around him while Wrath is alone thanks to wrath being an isolating emotion: Undirected anger is a threat to everyone around you.
• Food as Bribe: The original reason that Shiraori travels with Demon Lord Ariel back to demon territory. For why she stuck with her afterwards, see Aw, Look! They Really Do Love Each Other above.
• Forced to Watch: Hugo arranges for Shun's maids and older brother to commit suicide in front of him the instant Shun can see them.
  • Shun knows that Hugo will do nothing to his sister because he will wait until Shun is there to see him kill her.
  • Shiraori forces Sariel to watch when she sends the Queen Taratect to destroy the First Army and the human fort it is attacking, telling her she only did this because saving the Hero system from deletion consumed energy Shiraori was stockpiling. Wiping out both armies was only necessary to replenish what Sariel wasted.
• Foreshadowing: When the main protagonist uses appraisal on herself, it says "no name" and she had nearly no Skill Points compared to other students. This is significant because the main protagonist isn't actually part of the class, but rather just a spider inside the classroom. She also notes a strange feeling of familiarity after meeting Gyurie which derives from the fragment of "D"'s soul embedded in Kumoko.
  • Shun and his friends muse that Bald-san's skills are beyond human ability. Wakaba Hiiro who plays Bald-san is Evil God "D" and not above using divine powers in a game, though she normally doesn't.
  • The spell intended to reach the Administrators instead exploded in the classroom and "D"'s use of Japanese and a smartphone indicates she is currently in Japan as Wakaba Hiiro.
  • Shun notes that despite Hugo being more than deserving of death, he strangely doesn't want to kill him. This confuses him as he's unaware the Kindness skill is distorting his soul.
  • Oka-chan's class list has a blank spot where a student's name should be. Wakaba Hiiro is still alive on Earth so her name is absent. She assumes this means they died before she thought to check.
  • Julius and the king discuss a few times how Shun and Sue are probably estranged from the latter because he can't do much for them as a father with his responsibilities, but will eventually understand in time. Shun is more mature than they realize so it seems like needless worrying on their part. However, that only applies to Shun. Sue has grown to be completely apathetic at best to her country and family, both of which have treated her and Shun quite poorly.
  • The light novel adds in more foreshadowing for Kumoko having been a mere spider that was given false memories by placing more emphasis on her memory gaps and having Shun have a dream where he sees her web in the classroom.
  • In Volume 6, Gyurie comments on how Kumoko/Shiro isn't so different from D during their drinking session alonside Ariel.
  • As many readers note, Kumoko is slightly odd early on in that she seems to think more like a spider with human intelligence than a human trapped inside a spider body. This is exactly what happened.
  • In the anime, a quick mention of Julius' scarf reveals they got the materials for it and a earth dragon egg from a spider's den fifteen years ago. This shows the viewers early on that the story we are seeing with Kumoko and the other Reincarnated Students are not happening at the same time, but a several year gap in between.
  • In the anime, Hyrince, one of Julius' comrades and one of the few survivors, claims Julius was killed by a woman in white using Rot Evil Eye. The next scene has Kumoko looking at that very same skill. Foreshadowing she is that woman 15 years later.
  • When confronted by the Vestiges, one of the things they repeat to one another is "Cannot appraise". This response hints at Hyrince being a clone of Gyurie, the first being to display that message to Kumoko. Goes double in the anime where Hyrince is looking at the camera when this is said while the others face away.
  • In the anime, the very first scene is partially shown from an unusual segmented view high on the ceiling. Which makes sense, because we are seeing it through Kumoko's original eyes, ie. a spider.
• Forever War: The Demons and Humans are trapped in an unending war, with the closest thing to peace being an uneasy cold war.
  • This situation began shortly after the collapse of the ancient civilization when humans began to persecute demons due to them being humans who evolved using MA energy. The demons consolidated into a nation for self-defense, creating the current situation.
• Four-Philosophy Ensemble: Seen with Shiraori's team. Shiraori is the Realist,^note sees what's happening in the world and is resolved to do what's needed Ariel is the Apathetic,^note content to go along with Shiraori's plan Wrath is the Optimist,^note very moral and wants to help and Sophia is the Cynic.^note generally dislikes everything and quick to find flaws Gyurie stands apart as the Conflicted.^note knows that his own methods failed and believes he lost the right to lead due to complacency
• Four-Temperament Ensemble:
  • Once again with Shiraori's team. Shiraori is Phlegmatic,^note introverted with a forward-looking view Ariel is Sanguine,^note cheerful and acts as a foil for Shiarori's awkwardness Wrath is Choleric,^note his temper is getting better but he's still steadfast in his beliefs and Sophia is Melancholic.^note often glum and focused on her own issues Gyurie is the neutral Leukine.^note very balanced personality
  • The Puppet Taratects of Ariel are this. Ael is Phlegmatic^note The Reliable One amongst the puppets, Fiel is Sanguine ^note the Troll of the puppets, which annoys Shiraori to no end, Riel is Choleric^note The Ditz of the puppets and Sael is Melancholic^note  the Shrinking Violet of the puppets.
• Fragile Speedster: Lightning dragons are the type that are typically the most troublesome for humans and Wrath. They have one of the most annoying attributes and aren't even that rare as far as dragons go. The reason they're so difficult is that they have very high power and are the fastest dragons. As a result of their natural speed, however, they never develop their defenses much because they don't get hit often. Further, they also have poor longevity as they tend to spam high powered magic.
• Freak Out: In the web novel, after learning what the Taboo skill is, Kumoko absolutely loses it for awhile and goes from completely happy go lucky to being disgusted with humanity and slaughtering more than a few. It's indicated that this is mostly due to the outside influence of Ariel's hatred seeping through the Kin Domination link and she eventually calms down again. However, she permanently loses the aversion she had to killing humans and her personality becomes somewhat less goofy.
• From Nobody to Nightmare:
  • Our cute main character was born the lowest of monsters who wanted nothing more than to eat delicious things but within two years had become a man-eating god. Applies doubly when considering her origin as a house spider in Japan.
  • Similarly, her ally Wrath/Kyouya started as a goblin before evolving into an oni everyone fears and one of the strongest beings within the System.
• Gambit Pileup:
  • The war between the ancient civilization and dragons ended with a struggle between Gyurie, Dustin, and Potimas over the fate of Sariel. Gyurie came the closest to winning with the backing of "D".
  • The war Hugo starts is a mess driven by multiple parties with their own agendas. D, Shiraori, Dustin, Gyurie, Sariel, Potimas, and Ariel are the main drivers, with Shun, Hugo, and Oka-chan largely being pawns.
• Game-Breaker: In-Universe
  • The Sin and Virtue titles carry massive advantages with them, though most of them are also secretly very dangerous as well unless you have maxed Heresy Nullity. Since this stat is hard to acquire, most people can't do much with them without being terribly warped.
  • The Hero skill given to the proper hero has secret advantages built into it. For example, if one hero dies, the next hero gets more out of the title when facing the Demon King. This increases until the Demon King finally loses. This apparently doesn't go in reverse because it's intended as a balancing feature against the Demon King, who is assumed to be stronger by default. Also, in the case that the hero is vastly and hopelessly outclassed by the Demon King, such as a hypothetical fight between Shun and Ariel, then the hero gets proportional buffs to make it a fairer fight. Shiraori considers this cheating. Presumably this one also goes in reverse since the Demon King and Hero must always be capable of defeating each other, but this isn't explicitly stated and is indicated to not really be an issue.
  • The Hero skill has an even more secret advantage built into it, which is it allows the bearer to tap into the MA energy when they attempt to attack a god. This is what depleted the MA energy when the Hero attempted to attack Evil God D. Shiraori notes this is almost certainly an intended function to amuse D.
  • Finally, Shun's personal skill of heavenly protection makes any outcome he wishes for easier. Shiraori considers this one to be particularly unfair, especially since the limits are so vague. Combined with the buffs Shun would get if he met Ariel, Shiraori absolutely refuses to let them meet.
• Game-Breaking Bug: The skill system is imbalanced due to a secret title, "Subjugated by Hero", received by being defeated by the Hero. Its existence is an unintended drain on the limited energy supply and is helping accelerate the collapse. The title doesn't last long since it's being gained by Julius killing Shiraori's clones, the title going to her since they're a part of her and then being rejected since she can't have titles anymore. This seems to be a big part of why Shiraori decides to kill Julius: Every time he kills one of her clones, the System grants it a tiny but real amount of energy that is then lost forever to the System. The other reason is that she wants to get rid of the hero title altogether since it's also a huge drain of resources that the System can't afford to waste.
• Generation Xerox:
  • Ariel, her biological granddaughter Shiraori, and Shiraori's basically adopted daughter Sophia, not by appearance, but by experiences and personality. The three had their childhoods unintentionally screwed up by an Administrator; like to screw with other people (only for it to backfire on them); while talented and powerful they would much prefer to laze/play around but still work hard because they have to; have quite the appetite (for blood in Sophia's case); are morally ambiguous; want to make their mother figure proud (Sophia to Shiraori to Ariel to Sariel); and are kind of an idiot (it's implied Ariel was like this before Sariel's sacrifice). And they can be really petty.
  • As an Arachne, Kumoko looks like a mix of her progenitors: her grandmother Ariel and her other self Wakaba Hiiro AKA her "mother" D. Upon ascending to godhood, because of the bit of her "mother"'s soul she got, Shiraori looks like an exact albino copy of D (except for her eyes, which have 4 red demonic pupils a piece, instead of two horrifying black holes). The two even use this to go partying (against Kumoko's will) as black and white witch twins one Halloween.
• Gentle Giant: 3rd army commander Kogou who is constantly mentioned to be a giant and a pacifist.
• Get A Hold Of Yourself Man: In volume 12, Hyrince has to snap out Julius into reality when the latter is denying to himself that Yaana is dead after being crushed by a Queen Taratect's leg.
• Giant Spider: Taratects range from the size of a pig to larger than whales. Horo Neia seem to cap out at pig sized.
• Gigantic Adults, Tiny Babies: Newborn Taratects are the size of a pig while Queens are larger than a dragon.
• Gilded Cage: The settlement of the reincarnated people housed by the Elves isn't exactly gilded as they must manage their own crops and livestock, but it's still a very pleasant place to live compared to the harsher world outside the protective barrier. Despite this the students are painfully aware of how they're at the mercy of the Elves. Potimas wanted to keep their souls free of the System's effects before he began mass-scale experimentation on them.
• Global Currency: The Aleius coinage is the closest to a global currency as it's minted by the Divine Word Religion, making it accepted in every faithful country. Otherwise each nation has its own coinage which tends to be less valuable the further you are from it.
• Go and Sin No More
  • Oka-chan tries this on Hugo, defeating him and then stripping away his power. His response is to dedicate the next few years to getting strong enough to get revenge by destroying everything she's ever cared about.
  • After Hugo is killed, Shun adamantly claims he should have been left alive to atone for his crimes.
• God Is Good: Though Oka-chan is tricked into believing that the gods of this world are evil soul eaters who watch over the destruction of the world with amusement, in truth all three of the active Administrators are well intentioned people in their own ways. This isn't really typical of gods, though, who by all appearances seem to just be people with more power.
  • Sariel is the protector of the world and using her own life as fuel to keep the world barely livable while the people slowly repair it by fighting. Her personality is rather unsuited for anything complicated or requiring pragmatism, but she absolutely means well.
  • Gyurie is an administrator in the truest sense of the word: He's watching over the System and the people so that everything goes smoothly so that the world can return to normal. His passivity causes problems however.
  • Shiraori is the most morally ambiguous of the three, but she's the one that is actively fixing the 'bugs' in the System and trying to repair the fallout before the situation blows up entirely. Near literally, in fact. She has problems with empathy and planning ahead, however, and is too quick to jump the gun.
• God Was My Copilot:
  • Evil God "D" turns out to be both the famous online player "Bald-san" from the first chapter of the side story, and the real Wakaba Hiiro the other reincarnators went to school with.
  • Ariel's generals "Kuro" and "Shiro" are revealed to be the gods Gyuriedistodiez and Shiraori, though almost no one they interact with even know this.
  • Late in the story it's revealed that Shun's companion Hyrinth is in fact a clone of the Gyuriedistodiez.
• Godzilla Threshold: The imminent collapse of the System due to souls wearing out leads to Shiraori's plan to cause a massive war as the energy freed in the deaths of people can be used to prevent a disaster.
• Go Mad from the Revelation: When you reach Taboo Level 10, you get to find out the true nature of the Crapsack World, which usually drives most people completely bonkers. Even Kumoko temporarily goes on an Ax-Crazy murder spree after reaching Taboo 10. Some information is excluded and D also modified the skill to constantly bombard the user with feelings of guilt to ensure a breakdown.
• Good Thing You Can Heal
  • Kumoko would have died several times if it weren't for [n%I=W] restoring her damaged body. This includes replacing lost limbs and eyes, restoring petrified flesh, and healing a gaping abdominal wound.
  • As part of her first battle Sophia gets her head cut off, only for her body to catch and reattach it in one move. While her head was still severed she was losing HP at a phenomenal rate but hadn't quite hit 0 by the time it was reattached.
  • Wrath at one point has a hole blasted through his head. Only killing a knight and leveling up to restore his body saved him from death.
• Grand Theft Me: Kumoko attempts this on the Queen Taratects and Demon King Ariel, but only succeeded with two Queens. The Demon Queen's soul was able to resist Kumoko's fragment enough that they instead merged, which resulted in Ariel taking on some of Kumoko's traits. Admittedly she is a lot happier now.
• Gratuitous English: "Oh, Jesus!" Kumoko wails in the anime when she finds her siblings practicing cannibalism. Technically not English (since it's an Aramaic name, after all), but it's delivered in an American accent. In Crunchyroll's English subtitled version, instances of this are replaced by Gratuitous Spanish.
• Guide Dang It!: Kumoko's feeling about the skill system for quite a while as she has no idea how systems like magic work and has to figure out available skills by randomly guessing names.
• Had to Be Sharp
  • Ariel is the oldest and most powerful Divine Beast not because she was the strongest or smartest but because she managed to survive where her comrades died from, if nothing else, old age.
  • Kumoko herself starts as the weakest monster in the Elro Labyrinth without even full understanding of her abilities, but when forced to fight every day just to survive and keep herself fed she gets much stronger within a very short period of time. Within no more than a few months she becomes one of the most dangerous beings in the labyrinth with only the earth dragon and Mother being absolutely beyond her ability to take down. The likes of Shun, by contrast, had to start as infants and even with seemingly genius level abilities had little chance to get any meaningful training done, taking years to accomplish what Kumoko had to handle within weeks.
• Half-Breed Discrimination: Half-elves are allowed to grow to adulthood in the Elf Village at which point they are banished. Anna' experience was apparently traumatic.
• Half-Human Hybrid:
  • Half-elves such as Anna are usually raised in the Elf Village before living out the rest of their lives among humans.
  • The country of interstice was home to a mixed population of Demons and Humans who had intermarried to the degree that pure-blooded members of either race were hard to find. It was very peaceful, but destroyed by Wrath due to him having gone berserk.
  • Both of the above interbreeding is justified by the reveal that Elves and Demons are just sub-species of Humans created through forced "evolution" with MA energy.
• Hammerspace: Spatial Magic allows for the creation of a pocket dimension to store items. Kumoko mainly uses it as a larder for excess food while Wrath stores his extra weapons in one.
• Heart Is an Awesome Power: The seemingly useless Heresy magic, used for little more than distractions through the story, turns out to be easily the most dangerous and likely difficult magic in existence. Sure, you can burn someone to death or whatever, but if they can regenerate it won't mean much. Heresy magic, however, affects and can even disrupt or break the very soul itself. There is no coming back from that, making it the most powerful weapon in fights between gods. The next most useful magic in a fight is Space magic, which wouldn't be strange except that the way it's applied is totally different from the normal uses of storage and teleportation and more similar to the basic magics like coordinate fixing!
• Henchmen Race: The Taratects were created by Ariel for the sole purpose of acting as her personal army; the Queens are little more than machines set to produce offspring which are in turn programmed to fight and become powerful. This proves to be a major vulnerability that Kumoko ends up exploiting. All the spiders are linked with the mother dominating their offsprings wills, which forms a connection that allows the passage of will/soul. Since the Queen Taratects have almost no will of their own, Kumoko's parallel will fragments find it rather easy to invade their minds and devour them from within, which serves as a staging ground to attack their mother, Ariel. Ariel is more resistant to this kind of tactic but still has no way to defend against it.
• Heroic BSoD: Learning that Potimas lied about why he wanted the students was the last straw for Oka-chan.
• Heroic Sacrifice:
  • Sariel willingly agreed to be killed and converted into MA energy to save the world. She actually had to be restrained by her friends and followers because she was so willing to do so.
  • In volume 12, Everyone in Julius's party had their fair share with their sacrifices, especially Yaana's, fueling Julius to stop and defeat the Queen Taratect Shiraori summoned.
• Hero of Another Story: All of the reincarnators were given abilities that could have let them become protagonists of their own stories. For most of them this potential was cut short by things like early death or being abducted by elves, but Asaka and Kunihiko did in fact have successful adventuring careers off-screen.
• Hidden Elf Village: The Elves live in a secluded forest village protected by a near-impenetrable magical barrier. This is needed as the Administrators and Divine Word Religion would both happily wipe them out if possible.
• Hilariously Abusive Childhood: Shiraori wants Sophia to be able to defend herself against anything that might try to hurt her, so she puts her through Training from Hell right from infancy. She starts 'slow' with having the baby trek through the wilderness under her own power and when resting has clones shoot magic at her if she doesn't improve quickly enough with her magic studies. Sophia actually does come to understand despite Shiraori's lack of explanation: Her own childhood was extremely dangerous and she could have died at any moment, which is implied to have traumatized her despite being played for laughs throughout the first part of the story.
• Hoist by His Own Petard
  • The halloween special started with Shiraori visiting "D" for candy (and to piss them off) dressed as a Cute Witch and ended with "D" deciding to roll with it and celebrate by dragging Shiraori against her will to a cosplay parade, where they will get photographed everywhere. The twin witches were really popular.
  • In a more serious moment after saving Oka-sensei from having her soul crumble and healing her collapsed body, Shiraori starts to (in a really childish manner) mock Potimas for erasing a part of his soul in the process, only for him to tell Oka-sensei that it was him who saved her, ensuring her loyalty, much to Shiraori's chagrin.
• Hopeless Suitor: Waldo becomes Sophia's first thrall after Merazofis, but she doesn't value him at all. He's so desperate to please her in any way that even his jilted former fiance Felmina finds him pathetic.
• Hopeless War: The war between the ancient civilization and the true dragons was never something the humans could win. Even with their best weapons empowered by MA energy, the best they could manage was slightly slow the destruction. While Sariel could easily best the true dragons, she could only be in one place at a time and the war covered nearly the entire world.
• Hope Spot: After Kumoko kills most of the subjugation team she lets the others go but tags them so she can locate the Labyrinth's exit. The survivors reach the surface only for her to teleport in and kill them.
• Horrifying the Horror: Wrath and Sophia consider Shiraori to be effectively invincible, so they're shocked to realize that there's someone out there that she doesn't even want to think about challenging.
• Humans Are Bastards: The story presents humans as being willfully ignorant, almost universally selfish and while they do admire the true heroes like Shun and Sariel, they have no desire to emulate them. They're happy to just take advantage of their kindness and then turn on them when their own well-being is at stake. As a result, Shiraori tends to find them slightly distasteful by default when viewed as a whole.
• Idiosyncratic Episode Naming: The anime's episode titles all have a comma, and a question mark?
• Idol Singer: The anime ED features Kumoko as an idol, with other monsters (with glowsticks) as the audience.
• Ignored Expert: The Dragons warned the ancient civilization about the dangers of using MA energy and were uncharacteristically forthcoming about exactly what would happen. However, MA energy was just so valuable and the dragons so (rightfully) hated that they were ignored.
• Ignored Epiphany: Occasionally Kumoko's musings turn toward her own shortcomings and how she's not all that different from the monsters she is slaughtering. She then immediately dismisses such thoughts from mind and continues to behave in the same manner.
• I Let You Win: In the light novel, Sophia is openly with Hugo's group at the time Shun is trying to flee. Even though she is clearly not fighting at all seriously, she still barely manages to find a way for them to escape from her plausibly without actually seriously injuring any of them.
• Immortal Immaturity: Most of the reincarnators do not really act the age that they should mentally be, which would be their early to mid 30s. The author's defense (via D) is that many of them have had no opportunity to learn or mature because they've been locked away from the world in a hidden elf village that didn't want them to grow at all as people.
• Immortal Procreation Clause:
  • Demons have lifespans several times that of humans, so they "naturally" have a far lower birth rate and correspondingly smaller population. The constant warfare with humans has devastated their population and the decline in births due to damage from the System has pushed them to near societal collapse. Humans are suffering a similar decline in birthrate but haven't noticed due to their larger population and greater fertility.
  • Elves have even longer lifespans and mature far slower, having just enough of a population to maintain a single village. Such a small population can only sustain itself due to Potimas periodically kidnapping humans and converting them into new elves as breeding stock.
• Indy Ploy: Despite her reputation, Shiraori's plans are actually bare bones. She knows how to work the System, but when it comes to interacting with others she is absolutely winging it 100% of the time. The side details of her plans (such as killing Julius or training Sophia) are also only half thought out: She's bad at predicting consequences.
• In Vino Veritas
  • When Kumoko won't stop killing humans Gyurie gives up on that and just goes drinking with her to get to know her better and explain himself a little. We don't actually see the conversation for a long time but eventually we do see a chunk where he admits that he really can't argue with her calling him a loser, something she'd presumably said earlier in the conversation. Normally she keeps her mouth shut and her guard up around him, but when she drinks she babbles nonstop.
  • Shiraori is usually completely silent and withdrawn but when drunk she'll start childishly babbling about how to train, bemoan her rough childhood, and eat parts of Sophia's body.
• Irony:
  • Kumoko believes she was the least popular girl in class due to her anti-social nature, while pretty much all the reincarnated boys actually thought Wakaba was the hottest girl in class, considering her a mysterious "cool beauty." This may also be Kumoko's house spider memories mixing in, as no one other than Oka liked it.
  • One of the experiments Potimas discarded as a "failure" turned out to have an immortal body after all. If Potimas had had enough human decency to research how to neutralize his own daughter Ariel's poison blood, he could have had his immortality before even resorting to the extreme methods that destroyed the world. Potimas himself ruminates on how unfortunate this is right before she comes to kill him centuries later.
  • Dustin's efforts to save humanity by opposing Shiraori's plan are actually going to result in more human deaths / soul collapses than if she succeeds, as her plan will only cause the death of those with lots of skills, not the majority of humans, while letting the status quo go on will result in everyone suffering soul collapse from being processed too many times by the System. Worse, Dustin's attempts to recruit Shun to combat Shiraori could kill everyone instantly, as Shun fighting Shiraori would burn energy being used to sustain and rebuild the planet. Everyone except Shiraori that is, as she can just teleport away.
• It Can Think:
  • Monsters learn all their skills naturally as they lack the intelligence to buy them with skill points. Alaba proves dragons are intelligent by spending his skill points mid-fight to purchase a set of skills specifically meant to counter Kumoko.
  • To Kumoko's surprise, Queen Taratects are highly intelligent and can even understand speech as she learns after eating Mother's soul. They just have very weak wills because they're just a puppet race for someone much more powerful.
• "It" Is Dehumanizing: Gyurie refers to Shiraori as "that" rather than her name or even gender. However, while it is in part a kind of distancing term, it's also a sign of how he's nearly in awe of her.
• It's Quiet… Too Quiet: One of the warning signs labyrinth guides look out for inside the Great Elroe Labyrinth is that when they stumble upon an area without too much monster activity, there is a very high chance that an absurdly powerful monster is currently residing in that area, and flee that area as far as possible.
• I Will Punish Your Friend for Your Failure: Shiraori makes Sue flip by promising to leave her brother Shun alone. However, it's actually a kind of empty promise not because Shiraori hurts him anyway but because she had never planned to hurt him to begin with. So after Sue cuts ties, Shiraori admits to herself it was kind of an unfair deal and personally adds Sue to the list of people that will be sheltered when the System goes down.
• Jerkass Has a Point: Blow is disrespectful to Ariel and berates Shiraori for lazing around eating their food, despite them working to save the world. The reason for this is that Ariel is destroying the peace his brother fought so hard to maintain while Shiraori is gorging herself when the demons have just barely gotten food production above starvation level. Acknowledging this, she grudgingly forces herself to give a partial explanation and begins handing over some of the material from her clone's worldwide intelligence ring.
• Jerkass Gods
  • Oka-chan explains that the Elves are fighting against the System because the Administrators are using it to amuse themselves and feed off people's energy. Of course Potimas knows it's being used to restore the nearly dead planet, he just uses this lie to get people on his side.
  • Even D seems to have rather major distaste for some of the other divine factions. She consider dragons arrogant thugs while angels are basically stupid robots from her perspective. The latter are seemingly just treated with contempt, but she has major dislike for the former and always takes potshots at them.
• Jumping the Gender Barrier: Katia slowly developed feelings for Shun but suppressed them as she still identified as a man in her mind. After breaking free from Hugo's mind control she begins identifying as a woman and starts some low-key flirting with Shun. Shiraori comments that "D" reincarnated him as a woman in first place because she was aware in his previous life he was trying to force himself to have a crush on Wakaba to convince himself that he wasn't in love with Shun.
• Just Think of the Potential!: Potimas discovered a seemingly endless supply of energy that could be used to power entire nations and even evolve the human form. Nations greedily began exploiting this energy despite warnings, triggering an apocalyptic war with the dragons.
• Kaiju: Queen Taratects are enormous and incredibly powerful. A single one wiped out a heavily defended fort and the army attacking it.
• Kick the Dog: While it's later shown that Shiraori was controlling Hugo during his attempt at revenge, the story still makes an aside to show him doing really shitty things outside of Shiraori's instructions, causing her to have to cover up for him. That way she can be kinda morally shady without making him either terribly sympathetic or having her be responsible for the actual deaths he causes.
• Killer Rabbit: Shiraori's 3 palm-sized hatchling spiders that were summoned to guard Sophia.
  Shiraori: Although they are not strong individually, if there are three of them, they can at least repel the Dragon class.
• Kill the God:
  • Attempted on "D" by the previous Demon King and Hero at the urging of Potimas, or so it seemed. The attack was actually intended for Gyurie but was redirected by Sariel. As "D" existed outside the system and is effectively one of the Powers That Be, the attack failed.
  • Potimas has been constantly refining his robots and cyborgs in preparation for killing Gyurie.
  • Angels are a race of gods whose entire purpose in existence is killing every other god they encounter.
  • A god went on a rampage at one point millennia ago, slaughtering a large portion of the Angel race and quite a few other gods to increase their strength and skills in battle. The Maid really wishes "D" would stop bringing up her embarrassing past.
• Kingmaker Scenario: A variant. During the war at Sariella in volume 5, Ariel is teleported by Administrator Kuro in the battlefield in order to subjugate and kill Kumoko, incurring massive casualties in both armies of Ohts and Sariella in the process. Until Julius arrives at the battlefield, in which Ariel is wary of due to the hidden effect of the Hero Title and Kumoko uses it to her advantage. Ariel is then forced to use Abyss Magic towards Kumoko into that fight in order for the former to avoid fighting Julius.
• Know When to Fold 'Em:
  • During the Battle of the Elf Village, Fei knows that they don't have a slightest chance of beating Sophia and tried asking for surrender for everyone else's sake. Sophia almost accepts the surrender until the adventurer duo of Kunihiko and Asaka, barely beating Merazophis's clone, challenges her. This prompts Sophia and later Wrath & Shiraori to subjugate them.
  • When the adventurer duo finally comes face to face with Merazofis for the conclusive fight Kunihiko is promptly knocked unconscious by his partner Asaka, who is much more willing to acknowledge that the two of them barely managed to beat Mera's clone, let alone the real thing, and that he also would not be holding back against them like before. He lets them leave.
• The Lady's Favor: Goblins give pressed flowers to hunters leaving the village with the hope the hunter will return with the flower alive. This tradition is based on the flower Ariel gave to Gob-Gob, the first goblin, which he never had a chance to return.
• Land Mine Goes "Click!": Wrath buries easily broken explosive swords in a field. When somebody steps on the surface, the sword beneath shatters and explodes. This proves less than effective against magic once the trick is known: A single wind spell detonates the entire minefield.
• Laser-Guided Karma:
  • Hugo suffers near immediate reprisal whenever he raises his hand against Shun. Even if by the end he was being pushed to insanity by Shiraori.
  • Played for Laughs with Sophia unconsciously badmouthed her master and was immediately punished by Drunk!Shiraori.
• The Last Dance: Ariel is going to die soon due to the System distorting her soul. She decided to spend her last days doing what she had always wanted: Fighting to save Sariel.
• Last Fertile Region: Shiraori reveals that the two continents and surrounding oceans are actually the only livable portion of a mostly-dead planet. The purpose of the system was to accumulate enough energy to restore it.
• Lava Is Boiling Kool-Aid: The middle layer of the Great Elroe Labyrinth has rivers of lava liquid enough that the local monsters swim around in it. It notably averts Convection, Schmonvection though - without a Fire Resistance skill you take damage just from being near it.
• Last-Minute Baby Naming: Played With; As the Puppet Taratect sisters grew attached to Kumoko/Shiraori due to the latter transforming them into a Humanoid Abomination, Ariel immediately gave names to them as Ael, Sael, Riel and Fiel. Ariel then monologues on a skill called Naming which gives you power and ownership towards someone you named, which actually doesn't work on Kumoko when Ariel named her as Shiro since the former is already too powerful beyond belief. Ariel hurried to give names to her Puppet Taratects in response to Kumoko musing about naming them herself, afraid that the Puppets would shift their loyalties. They don't, but they become very fond of Kumoko anyway.
• Left Hanging: The Web Novel's ending ultimately leaves a great many unsolved plot threads, such as what Dustin plotted in targeting the Reincarnators with a dragon attack, what became of the Reincarnators who survived to the end of the war, especially Sophia, or even just who actually lived through the war without succumbing to some fatal condition soon afterwards, such as Ariel.
• Legendary Weapon: Weapons either crafted or blessed by D are considered a league of their own, though it can only be wielded by certain people. One such weapon, guarded by Gyurie's dragons, are the Hero and Demon Lord's sword, which is a one time use weapon that can kill even Gods using the planets MA energy. D's baseball bat, which can destroy everything in its path, even the invincible Elf Village barrier, thus kickstarting the slaughtering of the elves, and Shiraori's scythe, in which D blesses to be indestructible within the System.
• Legend Fades to Myth: The very existence of the ancient civilization has been all but forgotten. Most of the remaining knowledge of it and its destruction is contained in the teachings of the Goddess Religion as Sariel was the one who saved what was left of the world.
• Lethal Lava Land: The middle layer of the Elro Labyrinth is mostly lava with paths of solid ground or sometimes just islets. The heat alone is hazardous, not to mention falling into the lava or the fire drakes that live in said lava.
• Let's You and Him Fight: Invoked multiple times.
  • In the web novel, Shiraori deliberately manipulated Wrath and Sophia so they would encounter each other and fight even though they both ended up joining Shiraori's camp after talking for a few minutes.
  • Shiraori doesn't bother explaining her plans to the majority of the cast because she knows "D" will think without conflict things are too boring and trick everyone into fighting anyway. Which, of course, "D" does.
    System: A World Quest is issued: Will you obstruct or will you support the plan of the Evil God who is scheming to sacrifice humanity in order to avert the destruction of the world?
• Level-Up Fill-Up: The special skill [n%I=W] allows this for reincarnated individuals, completely restoring their bodies in the process. For Kumoko this was a vital skill until she learned healing Skills as it allowed her to recover from injuries that would otherwise have been disabling or fatal. At higher levels it doesn't completely fill the HP due to the soul energy it consumes being finite.
• Lies to Children: When Shiraori is making an analogy for why Gyurie's teleportation being interfered with injured him she uses the example of leaping through a doorway. However, before you go through it, someone closes the door and locks it, causing you to crash into it headfirst and hurt yourself. She admits that this is actually nothing like that but it makes intuitive sense, so just think that it works like that if you want.
• Life Stream: Every planet has a well of spiritual energy, comparable to that of gods but lacking a conscious will to direct it. If expended the world will die, along with any creature that lives on its surface. Potimas dubbed this "MA energy" and the ancient civilization, unaware of its true nature, abused it until the dragons stole what remained. The System is attempting to restore the MA energy but is on the verge of collapse.
• Lighter and Softer: The light novel, which is rated 13+, cuts down on some of the web novel's darker elements. Kumoko is more willing to help people, only resorts to cannibalism to avoid starvation and the first time she kills someone it's an accident, though she makes it clear that she has no real moral compunctions against doing so. Hugo only proclaims a desire to destroy everything Oka-chan holds dear, not flat out rape her. Katia is also never shown recognizing the need to abandon her parents, so they make it out fine. Volume five has some of the most significant differences, including cutting out Kumoko attacking both sides during the war, severely toning down Sophia's cruelty and making Ariel less amoral, but then still trying to proceed as though everything Kumoko and Sophia are doing is as terrible as the web novel.
• Literal Metaphor:
  Body in Charge: Information in Charge, we're burning up!
  Information in Charge: Oh yeah! Right now I can feel my soul burning brighter and brighter!
  Body in Charge: No! I mean we're literally on fire!
  Information in Charge: Eh? *looks at burning butt* AAAAAAAH!
• Living Relic: Potimas, Ariel, and Dustin are the only mortals left who remember the world before the System was created. Potimas has survived via Magitek; Ariel through her unique body; and Dustin through repeated reincarnation with the Temperance skill.
• Locked Out of the Loop: Oka-chan keeps everyone in Shun's party in the dark about the other reincarnated students as well as any details about the wider world. The only things she'll confirm is how many are under protection and, when pushed, that several died before she could help. But she only tells Katia this as both agree Shun would be upset to learn about it.
• Loose Canon: The "Teach Us, D-sensei!" side chapters have the gods D and Meido explaining various elements of the actual backstory of the novel with the exact same dynamics they show in the main story. However, the one they're explaining things to is the reader, so these Breaking the Fourth Wall chapters can't exactly be said to be occurring within the story itself, even if all the info and character traits in them are consistent with the main work.
• Loose Lips: Kusama leaves top secret documents lying around his personal quarters and blithely reveals inside knowledge to Wrath during conversation. Even Wrath, who's on the opposing side of the war, worries Kusama's too inept.
  Pope Dustin: Our ninja is so rubbish that it’s dangerous.
• Losing Your Head
  • Wrath cuts off Sophia's head during their first encounter. Her body catches it mid-air and reattaches it.
  • The third "Teach Us, D-sensei!" omake starts off with the Maid beheading "D". "D" is casual about the affair and gives the entire segment in this state, so the Maid follows up by reducing her body to mincemeat.
• Lost Technology: Though mostly destroyed by the Administrators, some of the ancient civilization's creations survived to the modern day, though only Potimas actually controls it.
• Love Chart: The author refer to it as "Shiro’s personal “heart” power ratings". This is specifically noted to be the character's opinion, though, and therefore falls apart somewhat on closer examination, because she isn't very good at reading people.
  Author Note (Chapter 276): Demon King > sensei > the Goddess = the pope > oni-kun >>>> The unsurpassable wall >>> vampire girl > loser (Kuro)
• Love Triangle: Between Sophia, Waldo and Felmina. Sophia doesn't even notice. Felmina eventually notices that Sophia gets much more invested and angry when Felmina competes for Shiraori's attention, though this is not romantic in nature.
  Shiraori: So this is a Love Triangle huh. It’s nothing to do with me though so I’ll evacuate. Let’s go.
• Magical Eye: The Evil Eye skills give a variety of status and damage effects to whatever the eye focuses on, one per each eye. Kumoko dreams of having a different one for each of her eight eyes. Demon Eyes are a weaker version. They remain one of her strongest trump cards as a god, especially the Evil Eyes of Gluttony.
• Magikarp Power
  • All skills start off pretty mild and barely have any noticeable effects. Level them up enough and things start to escalate exponentially. Case in point, the "Appraisal" skill starts giving nothing more than a general name such as "Wall" or "Deer" but at higher levels reveals every stat and in-depth details.
  • Taratects, Kumoko's species, are one of the weakest monsters there is. However, by picking to not grow to adulthood for as long as possible they start to eventually unlock very possible classes like Zoa Ere with the complete chain ending up at an Arachne, a humanoid spider monster. They can also end up being Arch Teratects or even Queen Teratects as well. The latter is even stronger than dragons.
• Magitek: The ancient civilization was comparable to modern day Earth until it discovered MA energy and incorporated it into their technology. Potimas took this even further, developing all manners of futuristic machinery using that power and protected by anti-magic barriers.
• Mana Shield: With the skill Perseverance^note Patience in some translations active, any damage that would drop your HP below 1 is taken off MP instead.
• Manchurian Agent: Potimas embeds fragments of his soul into people so he can control them, both indirectly and directly. He had compromised most of the government of one country and even placed a fragment in his daughter, Oka-chan.
• Man-Eating Plant: Some monsters grow like plants, only becoming mobile and hostile past a certain age. Goblin villages on Magic Mountain cultivated these monsters, making sure to harvest them just short of maturity.
• Maniac Monkeys: The Anogratch are a species of aggressive monkey-type monsters native to both the surface and the Labyrinth. They form troops thousands strong; if a single member of the troop is killed, the rest of them will seek vengeance no matter the cost. Their evolved form, Bagragratch, resemble giant baboons with huge claws and tusks, but despite being exponentially stronger individually are considered less dangerous since they lose the Wrath and Vengeance skills.
• The Man in Front of the Man: Demon King Ariel is eventually revealed to take her cues on the war's progress from Shiraori, one of her generals.
• Manipulative Editing: The information provided by the max level Taboo skill is all completely true, but strips out all the context to make mankind look as bad as possible when the actual order of responsibility is something like Potimas > D > Dragons > Sariel > Humans. Potimas knowingly invented world destroying technology and D gave a flawed solution so she could enjoy the ensuing chaos while also directly preventing anyone from improving the situation. The dragons dealt the killing blow and Sariel could have stopped it all at any time but refused to do anything but ask the humans very nicely to stop. Humans, meanwhile, were just tricked and then given warnings by people they had no reason to consider credible. Their greatest mistake, as a whole, was believing a disgrace bu brilliant scientist and not wanting to admit there could be anything wrong with MA energy.
• Mark of the Beast: Skills such as Heresy Magic and Titles such as Blood Relative Eater, are obvious signs of evil actions. Of particular note, the Divine Word Religion has a policy of locating and killing any person who acquires the Heresy Magic or Taboo skills as they are considered sinful and dangerous. Heresy Magic is actually banned because at max level it grants a level of Taboo and when Taboo is maxed, the person with the skill learns the truth of the world and goes crazy.
• Meatgrinder Surgery: Treatment Magic is generally only limited to healing injuries, not curing diseases. So when Kumoko decides to treat a woman and child suffering from organ failure, she has to sedate them and then tear out their failing innards and regrow healthy ones while they're unconscious in order to save their lives. She remarks that it's a rather barbaric method that would make any proper doctor faint.
• Medieval Stasis: The world has been stuck in its current feudal state for centuries at a minimum. It's enforced by the System, which prevents chemical reactions such as gunpowder burning; this ensures people fight the old-fashioned way.
• Metaphorically True:
  • The Taboo skill gives information on the world before the System was put in place and places the blame for all the bad things that happened on humanity. However, it generally leaves out the involvement of the Dragons, who stole centuries worth of MA energy. Potimas, who developed in the first place and hid the dangerous side effects till most of the world was addicted to it. and Sariel and Gyurie, who had the power to destroy all the MA Energy facilities but did nothing instead out of fear of "harming" humanity.
  • The system issues a quest claiming Kumoko is the "Evil God who is scheming to sacrifice humanity in order to avert the destruction of the world" Only the parts of humanity with high levels in the System will actually have to die, and trying to stop her is very likely to speed up the destruction of the world and all of humanity dying.
• Mind Rape
  • Heresy magic directly attacks the mind and soul, capable of implanting straight-up insanity into a target. Using Detection or Appraisal without proper secondary skills is a self-inflicted version.
  • Kumoko unintentionally inflicts this on Ariel during her attempted takeover. She survives the ordeal but as a result of merging with Kumoko's soul fragment her mind is permanently changed. Kumoko and Gyurie find the new personality pathetic, though the changes are actually more superficial than they originally seemed.
  • Level 10 Taboo not only reveals the origin of the System, it also bombards the mind with feelings of guilt. Combined, even mild-mannered people will go insane. It's significantly less effective on people who weren't born inside the System: Kumoko goes briefly berserk and the manga indicates it keeps her from sleeping properly, Shun collapses but stays rational due to getting a more complete picture of the situation while Wrath was already rampaging thanks to, well, Wrath.
• Mistaken Identity: When Kumoko finally leaves the labyrinth, before too long she ends up saving a young noblewoman who believes her to be a messenger of the goddess and a Divine Beast, one of whom is known to be a spider. Namely, she's mistaken for her grandmother Ariel, though her name isn't given for some time after this. Ariel is not technically a spider and certainly doesn't look like one, but reliable information about her is apparently scarce since she keeps to herself.
• Mobile-Suit Human: Puppet Taratects are human-sized mannequins controlled by the threads of a single palm-sized Taratect in their chest. Ariel's original models resemble mannequins but Shiraori helped her refine them to the point they can almost pass as an actual human. Among their species only Queen Taratects are stronger.
• Monster Is a Mommy: When Hugo attempted to kill Shun, he brought along a powerful earth drake to back him up. It was strangely docile, which puzzles Shiraori. In the web novel this is never explained and it's never mentioned again, but in the light novel it turns out to have been the parent of Feirune: It came along with Hugo's summoner because it needed to find its lost egg, then went on a rampage once it got where it needed to go. Unfortunately, Feirune and Shun kill it before realizing what it is, but Feirune is only temporarily depressed since she had no way of knowing and never grew up with it anyway.
• Monstrous Cannibalism: Kumoko finds that her siblings are eating one another after she hatches and that Mother is eating the new-born taratects as well. She later kills and eats one of her siblings, in self-defense and to not be wasteful. In the manga it was already dead, having been killed by an adventurer. This earns the "Kin Eater" title, awarding her the Heresy Magic and Taboo skills, both of which are considered sinful by the Church.
• Mook Horror Show: The fight between Kumoko and the human subjugation force plays out like this from the human point of view, with a horrifying monster appearing from nowhere to utterly decimate the armed soldiers with ease.
• Morality Kitchen Sink: The full range of morality is there but characters who really adhere to one extreme or the other and act on their beliefs are surprisingly rare: Potimas and Natsume are evil, Sariel and Shun are good. However, the viewpoint character is extremely gray when it comes to morality and finds both extremes distasteful: Potimas and Natsume are obviously assholes and major threats to every decent person on the planet, but Sariel and Shun's fixation on Doing The Right Thing is portrayed as naive, shortsighted and even outright dangerous: Sariel is one of the people most responsible for how shitty the world is while Shun's kind nature is something not even his closest allies agree with and, if events continue in typical isekai LN fashion, will put the world in immense danger, possibly destroy it and even if flawlessly successful will cause far more damage in the long run.
• Morality Pet: There's no reason that Shiraori has to keep the reincarnators safe, it's just something she chooses to do. She also took in Sophia and Wrath with no thought as the potential benefits and ensured their mental and physical safety as best she could even though she didn't know either one and owed neither anything. She has a particular soft spot for Oka-chan, though in that case it's mostly gratitude. Finally, Ariel is kind of a subversion. Her love for her grandmother is kind of sweet but her attempts to make her happy and give her life meaning are morally ambiguous at best.
• Mordor: Averted with the Demons' nation, much to Sophia's disappointment. It's actually hard to tell you've crossed a border between Human and Demon land since they're physically identical to humans, grow the same foods, organize their society the same way and have the same type of architecture.
• More Predators Than Prey: Kumoko notices that every creature in the lower level is a predator and wonders how the population can sustain itself. She eventually determines the likely reason is a number of small snail-like creatures. They taste horrible and inflict the damage of death itself on eaters so she reasons they're desperation food for the weaker monsters.
• More than Mind Control: Shiraori puts clones of herself into Hugo's brain so she can control him at will, but only directs his hatred towards specific targets rather than truly control him. He often surprises her by being more aggressive about it than she expected.
• Morton's Fork: There are two possible ways the planet can finish being repaired. Both of them are terrible.
  • First, the world continues warring until enough power has been drained from souls to fix everything. Before the world can reach this point, Sariel's soul will have collapsed from being too drained and then Gyurie will take her place and meet the same fate, only faster. Making it worse is that the Divine Word Religion is needed to keep things stable after Sariel dies, but Dustin is disbanding it to support Shun. Shiraori estimates that at least one quarter of the population's souls will die just from soul abrasion before that point is even reached, causing them to collapse like their gods'. This option is also risky in that things could get a lot worse, up to and including the death of the planet and everyone on it should anything go wrong. Shiraori rejects this plan as being the more risky of the two, but is privately mostly motivated by the desire to fulfill her dying grandmother's last wish.
  • Second, the System is forcibly shut down ahead of schedule and the energy used to power it instead going to fix the planet. This reduces the risk of soul collapse caused from soul abrasion, saves Gyurie and allows Sariel to simply die rather than have a Fate Worse than Death. Shiraori estimates that roughly half the population will probably die this way when taking into account the collapse of the civilization that depends on the System and the people whose souls will collapse immediately from having their skills stripped. This sounds worse on paper, but she's also making efforts to have as many people with lots of skills die beforehand as possible, which will keep their souls safe. So between the two, it's a bit of a wash as to which one is worse.
• Motor Mouth: Aoi Yūki/Kumoko's ending theme from the anime, involving describing the plot, listing her skills and having a mental breakdown. The full version takes it up to eleven.
• Mundane Utility
  • Kumoko's spider silk is a powerful defensive and offensive weapon which she can also use to go fishing. She just wishes the drakes and dragons she catches would have a little more dignity.
  • Shiraori has millions of clones scattered around the world, training and carrying out missions for her. She can also use them to metabolize alcohol out of her system and help her talk with people.
• Murderous Mannequin: Puppet Taratects are a rare mutant variety of the normal Taratect line that is even smaller than the basic hatchlings. They get their name from the way they inhabit puppet bodies that they control with strings and are actually between Arch Taratects and Queens in power. Shiraori didn't like their original bodies and spiffed up their puppet bodies so that they actually look like people now and are even capable of speech.
• My Skull Runneth Over:
  • Higher-level sensory powers like Detection or Appraisal can actually harm the user if they're not ready for the mental load. Detection is so overwhelming it actually counts as an attack on the user's soul. This is why most of the world uses Appraisal gems instead. It's implied that Appraisal, at least, didn't used to be so burdensome before souls started deteriorating so badly.
  • Taboo 10 allows people to remember their previous lives in the System. The amount of information instantly downloading into the brain is nearly crippling even with mental skills to ease the load.

Tropes N-Z

• Necessarily Evil: Goblins are considered just another kind of monster because they're very aggressive towards anyone that isn't part of their village. However, this can't really be helped: They only live to about the age of eleven or so unless they manage to evolve twice. Since you can only level by killing monsters or people, they have to constantly fight and kill just to reach the age where other humanoids are hitting puberty. Their short lives also keep them from developing more complex society because you can't have any kind of professional in a society with the massive turnover rate they have.
• The Needs of the Many: The reason the Divine Word Religion started a war with the Goddess Religion was because the Pope believed weakening them would save more lives in the long run once the Goddess died and her existence became common knowledge.
• Neglectful Precursors: The ancient civilization that produced the robots nearly destroyed the world by exploiting the MA energy, triggering a war with the dragons that left most of the world uninhabitable. Some of their creations remain, hidden and buried, which continue to cause damage.
• Nice Job Breaking It, Hero:
  • The previous Hero and Demon King's failed spell was intended to kill "D" and free the world from the System... despite D being one of the unkillable Powers That Be and the System being in place to heal the world that mortals destroyed. Instead, it just killed a classroom of innocents and depleted the MA energy critical to the restoration.
  • "D" instructed Gyurie not to kill anyone in the System, ostensibly to avoid disrupting it but in reality just to make things more interesting. Thanks to this and "D" losing interest, Potimas was able to run amok and indirectly was responsible for what MA energy had been gathered being lost when the Hero and Demon King tried to kill "D".
  • Neither Potimas, the Hero or the Demon King even knew of "D"'s existence or her role in the System. Potimas actually instructed them to try to kill Gyuriedistodiez because he was the highest Administrator and enforcer as far as Potimas knew. So, how did they wind up attacking "D"? Because Sariel took control of the spell and aimed it at "D" herself! It is ultimately Sariel's fault that all that MA energy was wasted and the spell caused the deaths of the children.
  • Sariel also throws a wrench on Ariel and Shiro's plan (reduce the strain on the System by killing Julius and eliminating the title of "Hero" while it's vacant) by forcing the System to select one, and she picks Shun knowing Shiro will avoid killing him like she did Julius. This not only opens up the "Hero" title to continue wasting MA energy, forcing the System like that also took more energy, so Shiro is forced to cause even greater devastation to make up for it, to Sariel's horror. Even Shiro loses her cool and harshly criticizes Sariel for her unwillingness to compromise her morals for the sake of greater good while stomping all over the efforts and feelings of those who do, especially Ariel's, who does it all out of filial love for Sariel.
• Nigh-Invulnerable: In one of the "Teach Us, D-Sensei!" chapters, Meido mentions about the strongest dragon called "The Unbreakable God", who boasts defense that invalidates all attacks and downright calling it a cheat ability. D sarcastically rebuts this and implies that Meido is much more of a cheat than the said dragon.
• Ninja Pirate Zombie Robot: Ael, a maid Puppet Taratekt co-created by Shiraori and Ariel to bodyguard and spy on the higher command of the Goddess Religion. Her species are actually palm sized spiders that control a marionette outer shell, and are actually just slightly below Queen Taratekts in terms of stats.
• No Accounting for Taste: Balto has no clue what his little brother sees in Shiraori. The answer is... well, she's scary, but Blow doesn't realize he fears her and mistakes his tension for attraction.
• Non-Action Guy: Half of the Demon Army thinks that Shiraori's Tenth Army is only good for spying and assassination due to their white outfits and Shiraori's tendency to run away from Blow. They are actually the second strongest army, right behind the Ninth Army which is full of humanoid dragons. Potimas makes the same assumption about Shiraori due to this.
• No Party Like a Donner Party: In the light novel, Kumoko only eats her spider sibling when she's not sure she can survive until morning unless she eats something.
• Normal Fish in a Tiny Pond:
  • Normally people are born with 0 skill points while the reincarnators start with massive amounts, such as Shun with his 100,000 skill points. This isn't actually a perk from "D" but rather a result of just how worn down souls trapped in the Skill System have become. The reincarnators have "fresh" souls with plenty of free energy to generate skills. The reason why Kumoko has so few skill points by comparison despite also being a reincarnator? Because while she's a "fresh" soul too, her soul is that of a simple spider implanted with memories by "D" which gave her sapience.
  • The giant snake that Kumoko faces when she is at level 9 of her initial stage, the snake was a more powerful monster than she had ever faced and she only won due to a combination of strategy and luck. When Kumoko accidentally falls into the second-lowest layer of Great Elro Labyrinth, it turns out that the snake is not that strong and a mantis that was even more powerful than the snake is easily killed by a giant spider.
• No-Sell:
  • By leveling resistances you can eventually gain immunity to the element you're being attacked by. Heresy Nullity is particularly valuable not because heresy attacks are common - they're banned by the dominant religion - but because unless your soul is immune to outside influences then the Ruler skills will burn through your soul and radically warp your personality.
  • Pain Nullity is in fact No Sold itself by a magic spell that creates the illusion of pain inside the mind of the target. Alaba is so unused to pain after so long with Pain Nullity that it causes him to flinch at a critical point.
• Nothing Personal: It's not much consolation to Shun, but Shiori killing his brother Julius was simply because she needed to take down the Hero system. She actually had some level of respect for him and gave him a quick, clean death as a result.
• Not Hyperbole: Kumoko's second maxed skill is Pain Resistance, which changes into Ignore Pain. She says she can't take pride in this because leveling the skill was literally suffering. Literally as in you gain proficiency by being in severe pain for extended periods of time.
• Not the Intended Use: D is rather pleased to see Kumoko using Parallel Will soul fragments to travel along mental connections and devour others souls. The ability was not designed to do this and figuring out a trick like this is an indication that she has aptitude for godhood.
• Not Quite the Right Thing: Shun's friends noticed that Hugo was fixated on him, so they did their best to keep the two separated. In truth, what Hugo needed was a simple wake up call. As his profile puts it, he was actually in distress and was signaling for help because he couldn't cope with the situation, but his difficult personality tends to alienate people. If Shun and his friends had tried to get him to open up he might have become a valuable ally instead of an enemy since he's not a fundamentally terrible person.
• "Not So Different" Remark: After reflecting on her treatment of Felmina, Sophia starts to think that Felmina must feel the same way that she did when Wakaba Hiiro (allegedly) ignored her existence. Only for her to get mad at Shiraori (who she thinks is Wakaba) for treating Felmina better than her.
• Not Worth Killing: Kumoko originally thought Alaba didn't notice she was still alive after it attacked her nest. Much later she learns it had the Detect skill and must have known she was still alive. Instead it let her live because a single, weak spider was not worth the effort of killing. Being spared for such a reason infuriates Kumoko.
• Oblivious to Love: Sophia noted her mother was an airhead who completely missed that her childhood friend and servant Merazofis was in love with her. Sophia's father noticed but knew it would never go any further.
• Official Couple: While Shun has numerous wannabe suitors, the one the story generally pushes as the main girl is Katia, though currently Shun is trying not to notice that she's a girl at all. It's still quite up in the air, however, and is a very small subplot to begin with. One that isn't even about characters who could be considered the main cast at that.
• Off the Chart: In the manga Kumoko makes a mental chart comparing her size to that of a human and Mother. Mother is represented by a giant claw with the leg going out of the panel.
• Oh, Crap!: The Elro subjugation team's reaction when they saw a partially eaten Arch Taratect (a ridiculously powerful S-ranked monster) corpse, a sign that something is actually strong enough to prey on it.
  • Kumoko did this a lot until she finally evolved into an Administrator, usually accompanied by a shout of "Nai wa!"
  • Kumoko when she realizes that most of her powerful magic abilities and even her powerful regeneration ability doesn't work against Potimas.
  • Sophia's reaction whenever Shiraori gets drunk.
  • Shiraori is not prepared to learn that the sea urchin type-robot she just killed with significant effort isn't the "final boss" of Potimas's robot army - it's the production model version. It's not enough to pose a serious threat to her, but it does force her to use her anti Gyurie trump card in front of Gyurie himself. Fortunately, he doesn't have the time to work out a countermeasure before the two begin their own fight.
• Old Maid: Despite making her age secret, Aurel complains that despite way being past her prime marrying age, she's still single and haven't even entered into a relationship once. Before she became Ronandt's apprentice, her family is so poor she couldn't marry herself off. After being Ronandt's apprentice, she becomes too busy to think about romance while her suitors is too much in awe of her to ask her out.
• Ominous Walk: In the anime, Ariel does this when meeting Kumoko at the first time and kills the latter.
• Once More, with Clarity:
  • Pops up periodically when two characters are involved in the same event but are either opposing or unaware of one another. Examples include Shiraori intervening after Oka-chan depowers Hugo and showing both sides of the battle between Wrath and Sophia.
  • Several cryptic conversations among the demons surrounding the Human-Demon war are revisited much later. Not only do they have context that was originally missing, but the conversations are also told from the perspective of somebody who knows what's actually happening.
  • The first opening of the anime has a scene of Wakaba looking at herself trapped in webs, seemingly a stylized metaphor for her mind being trapped in a spider body. Until it turns out to be a representation of an actual scene later in the story. Namely, it turns out Wakaba/D and Kumoko/Shiraori are entirely different people, and this is in fact D watching as Kumoko achieves apotheosis and goes from a half human arachne to a fully human-looking goddess.
  • A scene in the opening and first episode shows somebody who seems to be an outsider observing the classroom from odd angles. Episode 17 shows it's in fact Kumoko in her previous life as house spider, who'd made a home in the classroom.
• One-Steve Limit: Averted with two skills: Hero and Demon Lord. There exists a version of each that can be earned or purchased via the usual skill system and the unique version that the System automatically gives to a single person. The former is merely a stat boost while the latter is a stat boost and marks them as the leader of humanity/demons. It's indicated that having the Hero or Demon Lord skills make you more likely to be picked the next time the spot becomes vacant, however.
• Organic Technology: Queen Taratects are actually highly intelligent, but they have almost no will of their own. Kumoko compares them to giant walking computers that only fill out a handful of preprogrammed instructions. She seems to find the idea intriguing and useful. Not only she she exploit the link between her and Mother to devour the weak minded creature, but also creates more Horo Neia to serve as backup bodies and later small clone offshoots of herself with similar instructions.
• Orphanage of Love: In the Past Arc, Sariel manages an orphanage which houses most of Potimas's experiments. Sariel loved and cared for them that when she becomes the sacrifice for the System, most of them plans to free her and Ariel herself plans to create a genocide for the ungrateful humans.
• Otome Game: Sophia is unaware of it, but her time at the noble's academy hits all of the cliches as she obliviously builds a reverse harem and garners the hatred of a scorned fiancee whose social standing is destroyed as a result.
• Our Angels Are Different: Angels are a race of gods whose entire purpose is exterminating other gods and protecting "primitive" species such as humanity. They evolve by taking power from the gods they kill; they apparently gained a humanoid form after killing the god who created humans. They're usually emotionless and behave more like machines than living beings. Sariel is a "stray" Angel who was left alone after the Maid destroyed most of her race. She gradually developed primitive emotions and opinions but retained her desire to protect weaker species. Strictly speaking, this was not a good thing as it led her to doing some seriously stupid things out of good intentions.
• Our Demons Are Different: Demons are physically indistinguishable from humans and their culture is very similar as well. However their physical parameters are much higher than a comparable human and some inherit demonic abilities. The similarities are due to demons being the descendants of humans who "evolved" using MA energy. Overall their race is less numerous, which causes them to feel the effects of the overall lowered birthrate far more strongly than the humans do.
• Our Dragons Are Different
  • True dragons are gods, or at least become them when they reach adulthood. They're dicks. They can also assume human form, though if Gyurie is anything to go by they don't actually look quite human: He's solid black from head to toe with only his red eyes looking different. Additionally, the armor he always seems to be wearing is implied to be his skin.
  • Mature dragons vary in appearance both between and within their own species. Earth Dragon Alaba looks like a giant scaled dog thing, Earth Dragon Kagna looks like a turtle-monster, and Fire Dragon Rend is a traditional winged dragon.^note Although he lacks wings in the manga, instead possessing massive shoulder spikes. Like true dragons, they can assume human form. However, it's not clear if this is a natural ability of theirs or if Gyurie is rigging the System.
  • Dragons are the evolved form of drakes/wyrms, which in turn can evolve from other low-level species. Only high-tier drakes like the Elroe Gunesohka look like dragons, while lower-tier drakes range in appearance from dinosaur-like Earth Drakes to fish-like Fire and Water Drakes. Kumoko is baffled at how two of the fire drakes look like seahorses and catfish; the eel-like drake at least has an Asian-style dragon body. It's eventually revealed that most of these dragons are descendants of Potimas's experiments in merging dragon DNA with other animals.
• Our Elves Are Different: Of the Wood Elf variety, they are a neutral nation that lives in a magically defended village. They have extremely long lifespans and generally view other races as needing guidance. Potimas created their race during his research into immortality by forcibly evolving humans. Every elf is either brainwashed to serve him or is a clone containing a copy of his mind; he maintains genetic diversity by abducting humans and evolving them into elves for breeding stock.
• Our Goblins Are Different: Goblins are short-lived and weak humanoids who reproduce quickly. They are primarily hunters but also practice some farming and form small tight-knit villages. Though not very intelligent because of a lack of any means to educate themselves, they are clearly not stupid and have great love for their families. Their goal in life is to live and fight long enough to evolve into longer-lived hobgoblins and aid their family in doing the same. Due to their short lives they have to hunt aggressively and so are considered monsters by humans. In truth, they're simply modified humans either descended from Gob-Gob or built in his image by D.
• Our Gods Are Different: Gods are beings whose souls have evolved to the point that they can absorb massive amounts of magical power, allowing them to transcend most mortal restrictions. Entire races capable of becoming gods exist, such as Gyurie's. Angels, on the other hand, seem to be a defense mechanism created by planets to destroy more dickish gods. Titans are the oldest faction and others are indicated to exist, but play no role in the story and are therefore not mentioned much.
• Our Ogres Are Hungrier: Ogres are an evolution of goblins, which grow larger with each evolution. They tend to wield crude weapons and move in large groups. Wrath was unusual not only due to his weapons and intelligence but also due to being alone. The Oni is a special evolution of the Ogre which looks identical to a human aside from two horns.
• Our Vampires Are Different: There are two different types.
  • Sophia and those she turns are physically and magically much stronger, but have a tendency to either view humans as food or at least quickly grow uneasily comfortable with controlling them. Walking in the sun is uncomfortable for her kin and all require blood, though it can be taken without turning the victim. They specialize in blood and charm magic.
  • Natural vampires are essentially supernatural rabid animals. Both animal and humans lose their minds but become physically much stronger. They attack and feed on other animals, with a single bite being enough to transfer the infection. Regaining one's mind after being bitten is very rare.
• Parental Abandonment: Shiraori feels the behavior of "D", who essentially created her, is even worse than this because she fully expected Shiraori to die.
• Patricide: Ariel kills her father, Potimas, to avenge all the suffering he inflicted on her and her siblings.
• Perception Filter: Shiraori uses a spell that causes people to only perceive her as "white", forgetting any other feature. Repeated exposure or familiarity with her appearance grants immunity to the effect. Dustin is startled to realize that he didn't even notice while speaking face to face at length.
• Perspective Flip: The story slowly develops into a reverse of the general isekai plot with the hero being a tertiary character generally reacting to events in the background while the 'villains' are constantly struggling to try to actually fix problems, though they are pretty morally gray at best. Thanks to the story focusing so much on the morally ambiguous villain side, the hero's claim to moral superiority ends up ringing a little hollow. After all, it's easy to stick to your morals when you've never had to make a hard decision, let alone one like 'be a slave or kill the person oppressing you' or 'starve to death, get butchered or be willing to get your hands a little dirty.'
• Perfectly Arranged Marriage: When Katia and Shun are summoned together in the castle during the events of the first volume, Katia remarks that Shun's father might be about to announce their engagement. After all, arranged marriages happen in this world, especially amoung the nobility. The two of them are a prince and a duke's daughter, who are the same age, and so friendly with each other that they use nicknames. After establishing this, Katia makes clear that she doesn't want to marry a guy at all, but since it's inevitable for someone in her position, she'd prefer to marry Shun, since they are friends and he understands her whole deal. Shun agrees, saying that such a marriage would be "convenient", since they could carry on with their relationship as normal.
• Planet Looters: The true dragons chose to depart the world rather than continue their battle with the ancient civilization and Sariel, but took the entire planet's MA energy with them.
• Please Kill Me if It Satisfies You: The Pope offers this to Sophia as compensation for the war that killed her parents. This has less impact than it first seems as Dustin will just reincarnate and become Pope again. However, the time lost at this critical juncture would still cause a significant problem to his plans.
• Plot Hole: In the light novel, Gyurie passes Ariel information about Kumoko's personality without ever having spoken to her. In the web novel this is because they'd gone out drinking together beforehand and she opened up while drunk, but in the light novel he should have no way of knowing what Kumoko is like.
• Poor Communication Kills
  • Shiraori is almost completely unable to speak to people she doesn't know well, which is a weakness she doesn't really try to overcome. As a result she alienates a lot of people. It's doubly unfortunate because there are occasional hints that her behavior would improve significantly if people would just sit down and talk to her: Sophia has to put up with drunk Shiro comedically abusing her for years because Shiro doesn't remember anything she does while drunk. Once Wrath scolds her, she immediately stops.
  • If Blow had known that nothing Julius could do could possibly hurt Shiraori, he could have evaded an attack that basically ended the fight. Instead, he tried to shield her and the soldiers with her. Worse, the fight may not have needed to happen or could have at least ended with Shiraori stepping in to save him: Before the fight, he asked her to not interfere because he thought she would just get killed, but she thought he meant it would hurt his pride.
  • The ancient civilization ignored the warnings of the dragons and Sariel about abusing MA energy because they didn't actually give the reasons why it was a bad idea. The civilization went ahead and triggered a war that led to the world's current state.
• Post-Modern Magik: "D" communicates with Kumoko via a teleported smartphone.
• Power at a Price
  • The entire skill system works on this principle. The System forcibly alters people's souls to give them new abilities, and cuts chunks off the soul after death to repair the planet, before reincarnating them for another round of processing. Too many skills in one lifetime or too many reincarnations through the System will eventually result in your soul warping or collapsing completely. Further, the 14 ruler skills are so powerful the modifications they cause on your soul seriously warps your personality if you don't have Required Secondary Powers like the Heresy Nullity.
  • On top of system access rights, the Ruler titles all grant a unique skill such as Enma (from Wrath) or Hell (Pride) powered by what's known as the Divine Area, meaning that if you use them, it will decrease in size. Since the Divine Area by itself seemingly does nothing, this isn't terrible alone until it's revealed that it's basically a measure of your soul's capacity, so using a Divine Area powered skill literally burns part of your soul. Further, gods are beings whose souls would be classified as having a Divine Area of level 10 by the system, so using the skills are making it harder to potentially become far more powerful and free from the negative effects of the system down the line.
• Power Copying
  • Skills can be learned by observing someone utilizing it and then copying their actions until the Skill manifests. Kumoko can cast unlearned magic spells by manually retracing how the magical energy is configured by the spell while Wrath acquired a sword master's skills by imitating his movements. This becomes an essential skill to defeat the security robots at the underground facility, by copying their anti-anti-magic field.
  • Kumoko learns several magic types by simply watching others cast them, including earth, lightning, wind, water and fire magics, though by this point she doesn't actually need them at all. She gets confused at how Sophia has no clue what she's supposed to be doing when she sets clones to both protect Sophia and to repeatedly cast magic in front of her so she can see how it works.
• Powered by a Forsaken Child: Skills are created by the System directly manipulating the soul while XP is generated by recycling the soul of the killed and giving part of the energy to the killer.
  • Even worse is the revelation that the deficit between the energy consumed versus the energy available in the System is made up for by directly draining energy from the Goddess. She's being drained to death and Gyurie will be forced to take her spot afterwards.
  • Potimas's robots contain massive amounts of power, which Ariel sadly notes comes from souls. And since souls have a limit on how much energy they can hold, the more powerful robots must contain a lot of them.
  • MA energy, which Potimas and the ancient civilization abused, is in fact the spiritual energy of the world.
• Powers as Programs: Skills are programs executed by the System to produce desired effects. Something targeted by a skill in turn has programs such as resistances that register the effect and determine the damage done. To a being outside of the System, many attack spells are harmless as they have no actual effect other than what the System registers.
• Power Born of Madness: On the flip side of With Great Power Comes Great Insanity below, the Seven Deadly Sin and Seven Heavenly Virtue skills are all earned by either great affinity for a skill or slowly unlocking it over time. That's all well and good, but in practice this means that to earn Wrath, for example, you need to be in a state of great rage for a long time to the point where it permanently affects your basic personality. Only then do you your nifty new broken skill. And getting the skill just makes your descent into madness or obsession even faster.
• Pragmatic Adaptation: Two frequent criticisms of the web novel are that the pacing is very slow with a lot of time spent with Kumoko playing around with skills and that with only her as a viewpoint character the narrative can be a little dull. So in the light novel, there's less time spent sitting around just practicing and the chapters tend to alternate between Kumoko and Shun's perspectives to keep things more interesting.
• Pragmatic Villainy: It's noted that whatever else may be wrong with Shun's usurper brother, he would still send forces to assist the war effort against the demon king without hesitation if the country was politically stable enough to do so. After all, he's just another target.
• Pretext for War: Sariella and Ohts go to war after Kumoko kills a noble from Ohts who is visiting Sariella. However she notes that the Ohts army arrived suspiciously fast and suspects they'd been looking for an excuse to attack.
• Prevent the War: The Elves are constantly trying to maintain a peace between the humans and demons, acting as ambassadors and covert agents targeting dangerous elements. This is solely to match with Potimas's self-serving plan rather than because he believes in peace.
• Pride:
  • Shiraori's central philosophy. This starts with believing it's not just enough to survive, and if she's going to live she's going to live proud, fighting without running away or giving up on what she wants. This later extends to her discomfort with having to be beholden to D, and trapped within D's plans her whole life. It's also the reason she cares so much for Ariel, as Shiraori sees her as a being with such pride she's willing to challenge the entire world and even the gods to get what she wants. However, while she holds pride to be the most important thing for a person, she knows she fails to live up to her own standards because she won't fight unwinnable battles just for the sake of pride, which lowers her self esteem further.
    Shiraori: In my case, I don’t yet have a belief that I can be puffed up with pride over. I have no pride. That might be the exact reason why I seriously want to help this proud Demon King.
  • Pride is also one of the Seven Sin Skills, and grants the user a massive boost to skill development speed. D notes it's probably the most outrageous skill in the system and the most deadly, as skills and exp warp the soul, meaning pride accelerates the process of losing your sense of self, and ending up Deader than Dead when your spirit collapses, faster than any other.
• Prolonged Prologue: The story proper arguably doesn't begin until Chapter 151 of the web novel^note or volume four of the light novels when Kumoko finally escapes the Labyrinth; at that point she begins interacting with the outside world and the plot begins to reveal itself. Until then she's almost entirely concerned with survival and acquiring power to defend herself with only subtle hints that something is very wrong with the world.
• Puppeteer Parasite: Hugo is being manipulated by a hatchling clone of Shiraori, though she mainly uses it to nudge him in certain directions rather than fully control him.
• Quantity vs. Quality:
  • The Queen Taratects seem to be stronger than any of the Ancient Dragons and have nastier skills, but there are only five of them at the start of the story with one having died in the past. In comparison, there are apparently dozens of ancient dragons and with the queens having weakened thanks to Shiraori, they're not really capable of winning a 1v2 anymore.
  • For the Final Battle, one of Dustin's strategies against Ariel is a battle of attrition as the former knew how strong, especially the reincarnations on her side, they are. Which is correct since Wrath, after activating Wrath, easily slaughters the dragons of Shun's party and has only been defeated after Shun constantly reviving the said dragons via Mercy at the cost of his own soul. And Ice Dragon Nia, one of if not the strongest amongst the ancient dragons, is even overwhelmed against the Horo Neia's and even thinks her skirmish against Sophia is a Hopeless Boss Fight and plans to stall her as long as possible.
• Rage Breaking Point: Kyouya's anger was constantly growing after being tamed, but it was seeing his older brother turned into a tool that laughs about killing his own kind that finally drive him over the edge, unlocking the Wrath skill.
• Rags to Riches: Though Aurel is from a noble family, their family is so broke she couldn't even marry herself off until she becomes Ronandt's apprentice, which turned her life around.
• Random Power Ranking: Monsters and adventurers are ranked with a letter system, the understanding being that it takes six adventurers of average skill to beat a monster of similar ranking. D-rank is the usual starting point for adventurers scaling up to A- and then S-rank while Kumoko was born as an F-rank monster. Above S-rank is Myth-rank, given to monsters so powerful they can devastate entire armies.
• Read the Fine Print: In the backstory, D pointed out that Sariel's current plan to save the world was doomed to failure for several incredibly obvious reasons. As Sariel sits there stunned, D then offers an alternate solution: The System. Unable to actually understand the workings of it and at a loss because she has no clue what else to do, Sariel agrees without thinking, only to find that the System relies on constant unending warfare and bloodshed to heal the planet. Given her personality, she is not happy with the solution, but she doesn't (and probably can't after the contract with D was signed) give up on it.
• Reassigned to Antarctica: After Buirims fails to tame Kumoko, he gets assigned to an isolated village on the Magic Mountain on the border between the Humans and Demons. Unfortunately, it's so inhospitable that nobody guards it, leaving Buirims with little to do other than kill local monsters.
• Red Herring: There's a lot of implications early on that Kumoko is going to become the Demon Lord, but the timeline doesn't really make sense. But that doesn't mean she isn't part of the Demon Lord's faction. In fact, if anything, she's her boss.
• Red Oni, Blue Oni: In the Adventurer Duo, Tagawa Kunihiko is the red to Kushitani Asaka's blue. Tagawa is so eager for revenge against Merazophis despite Asaka logically pointing it out that Merazophis and the Demon side reincarnations are just toying with them, holding back their powers as to not easily kill them and the other Human reincarnations. It even ends up with Asaka knocking down Tagawa in order to ask for surrender.
• Reduced to Ratburgers: The first people Kumoko treats at her healing shrine are a desperate peasant woman and her dying young child. She can see that they both have the Filth Eater title, indicating that they were so poor that they had to eat rotting garbage. To cure them she puts them to sleep, removes their tainted organs and regrows them.
• Reincarnation
  • The Inciting Incident is an entire entire Japanese high-school class being killed in an explosion and then finding themselves reborn on a fantasy-esque world, including the teacher. And a house spider.
  • Pope Dustin the 61st has reincarnated 60 times, his first life having been during the collapse of the ancient civilization. He retains his memory with each reincarnation due to his Temperance skill.
  • Reincarnation without memories is standard for all creatures that possess souls, with a cycle that apparently allows them to be reborn on entirely different worlds. "D" sealed souls in the System so that they are immediately reincarnated on the same planet with no chance for the soul to rest, causing increasing damage as time goes on. The souls inside the System are nearing the point of collapse and causes most of them to be very weak. Thus, the reincarnators are only relatively strong: Long ago, they would have been nothing special.
• Reincarnated as a Non-Humanoid: Both the protagonist Kumoko and Feirun are humans-turned-non-humans, a spider and a (baby) dragon respectively. They both get humanoid form.
• Required Secondary Powers:
  • Poisonous creatures naturally have poison resistance, as otherwise their own poison would damage them. In the backstory, Ariel averted this, since she was a result of her father's experiments and predated the game-like system. As a result, she was barely capable of surviving due to her body constantly suffering from the toxins it produced.
  • Kumoko eventually evolves into a monster that ordinarily dies the first time it uses a Corrosion element attack that it has no resistance to. Luckily, Kumoko developed such a resistance earlier on, after having to subsist on corrosive bugs in a high level monster area.
  • Kumoko susses out that to use Detection she needs to improve her mental fortitude. By acquiring and leveling up abilities related to math and multi-tasking, as well as gaining a resistance to Heresy attacks, Kumoko is able to utilize it.
  • Almost all of the Sin and Virtue skills directly impact the soul, warping the mind over time. The best way to counter them is by acquiring Heresy Nullity, as it prevents the warping. Of course, you can only obtain the skills in the first place if they're already a Fatal Flaw in your character, so you'll still tend to indulge in them.
  • Magic skills can only be activated if the user has the Magic Perception and Magic Manipulation skills. Most monsters, including Kumoko, never learn these skills and remain incapable of magic.
• Respawning Enemies: A feature of the early days of the System caused monsters to randomly spawn. This can still occur but most monsters have developed large enough populations that they can maintain their numbers by breeding. However, thanks to Kumoko, by the time the story reaches the present the monster population inside the Elro Labyrinth has been so depleted that it's practically a ghost town.
• Restart At Level One: When a monster levels its class to the maximum, it can then evolve into a new form and return to level one. Doing so seems to lose most of the gained stats, which then rise again slightly faster than the last form did. New skills are generally gained as well. Apotheosis is similar in principle as well: Kumoko lost all of her System derived abilities when becoming a god and had to develop the real form of the spells they were based on. Plus, much to her annoyance, poison magic is not really a thing outside the System, so she can't use one of her greatest strengths anymore. However, while she only has strong aptitudes for dark, corrosion and space magic she believes that she'll eventually be able to reproduce the other magic types in general effect, though she wouldn't be technically using, say, an ice spell.
• The Reveal: Quite a lot throughout the story.
  • The previous Hero and Demon King teleported into the protagonists' classroom because the evil god who controls their world, D, was on a holiday as a Japanese school student on Earth.
    • Potimas had originally tried to convince the two to kill Gyurie, only for Sariel to forcibly redirect them toward "D".
  • The RPG system everyone uses is just a large scale application of magic created by D for some alternate purpose. This means effects like poison or elemental weaknesses are just complicated magic mimicking game mechanics.
  • The main character, Kumoko, was never a Japanese high school student named Wakaba Hiro. Instead, she was a house spider who was living in Wakaba's classroom. In fact, Wakaba Hiro is actually D, the self-proclaimed evil god of The Underworld, who gave part of her memories to the spider, then reincarnated it somewhere she expected it to die, so when it got to the underworld it would throw her boss/partner off D's trail a little while longer, and she could keep slacking off on Earth. Kumoko instead survived, which D found so entertaining she didn't want to interfere with the spider's exploits, and abandoned her original plan.
  • Shiro/Shiraori, the seeming Big Bad of Shun's side story, is actually Kumoko. And Kumoko's entire story up to the point the side story started was actually set a decade before Shun's.
  • The System is actually a Perpetual Motion Machine that absorbs the skills and experience mortals have gained over their life after they die to do something...
  • Further, the System is actually repairing the planet, as centuries ago humans created Lifestream eating Magitek that literally split the planet in two and killed 90% of all life. Also the previous Hero and Demon King teleporting onto Earth to kill D stole so much energy from the System that it'll fail in a matter of years.
  • The destruction of the world was caused by Potimas, who recklessly angered a faction of gods called "the dragons" and spread technology for abusing MA energy despite being one of the few who knew the damage it could cause. After the dragons devastated the human nations and then stole almost all the remaining MA energy and left, humans tried to sacrifice Sariel to restore the dying planet (though it would have failed due not only to Potimas sabotaging the process, but the fact injecting one soul into another all at once being a recipe for disaster) only for Gyurie to appeal for D's help, resulting in the System being implemented.
  • Which leads to: The System was far from the best solution D could have given Gyurie and Sariel. For instance, D could have trivially repaired the planet herself with her own massive amounts of soul energy, or allowed Gyurie to kill Potimas to make the whole process go much faster. But instead, she imprisons Sariel, tricks Gyurie into doing nothing, and spares Potimas, because it's more interesting to watch that way.
• Revenge Before Reason: The Anogratch's need for revenge is so powerful they completely disregard the actual cost involved. Kumoko killed or ensnared hundreds yet they kept coming, right down to the last member of their troop. When she saw them willingly plummet to their deaths so as to not get in the way of the other monkeys, she realized they would never stop hunting her until they were all dead.
• Right for the Wrong Reasons:
  • The people of Keren Country worship Kumoko as a divine beast because she's a spider who resembles the iconic divine beast spider who supposedly accompanied the Goddess in legends. In terms of her goals, motivations, and reason for being there at the time, Kumoko has nothing to do with the goddess... but in fact, while the legend is a heavy distortion of what actually happened, Ariel, her grandmother, is the divine beast who accompanied the goddess, so Kumoko is in fact a direct descendent of it. (Of course, what they're not aware of is that this is also true of every spider-monster in the labyrinth, who would certainly not be considered divine beasts.)
  • In volume 8, Buirimus mentions that the Empire is dealing with the damage done by the Nightmare of the Labyrinth in the outside world and holds him & Ronandt responsible because the Empire thinks they angered the creature. Kumoko didn't really intend to wreck havoc and has only got out of the labyrinth due to tracking Buirimus's hunting party with Wisdom.
• Roaring Rampage of Revenge
  • The main danger of the Anogratch, or "Revenge Monkey". A troop of revenge monkeys can be as low as several hundred or apparently in the tens of thousands, and killing a member will bring down the unstoppable rage of the entire troop on the assailant. Entire forts have been brought down by inserting a single Anogratch as a "bomb". The group that Kumoko narrowly defeated early on was as tiny a group as you could possibly hope to find.
  • Half the reason Shiraori starts the Human - Demon War is to get back at Potimas for using Oka as a hostage against her.
• Rotten Reincarnation: The standard cycle of souls in this universe is to rest in the underworld after dying before being reincarnated, usually on an entirely different planet. This cycle has been disrupted for the entire population of the isekai world, whose souls are now in a closed reincarnation loop due to D's skill system. The System distorts souls to create skills and then extracts those skills as MA energy when the soul's body dies. The souls are then forced to reincarnate far earlier than usual due to being cut off from the underworld and the strain from this and the Skill system is driving many to the point of soul collapse. While of this was ostensibly done to prevent The End of the World as We Know It via MA Energy depletion, the System is actually highly inefficient. D could have fixed things far earlier but the chance to Troll an entire world by turning them into a living RPG was too good to pass up.
• RPG Elements: Similar to other works in the Reincarnation genre, with a few twists. Shun and Katia note it's somewhat worrying that the System has only combat skills and skills that supplement combat; there are no crafting skills or similar.
• Rump Roast: Happens to Kumoko repeatedly during her stay in the scorchingly hot middle layer of the Great Elroe Labyrinth, due to her habit of unconsciously spinning highly flammable silk and letting it dangle from her backside until it catches fire in the heated environment.
• Schmuck Bait
  • The Ruler titles all grant awesome effects and unique skills, but they're actually incredibly dangerous to the soul of the user. Kumoko only gets away with using them as much as she does because she has high heresy resistance and later nullity, meaning they can't do too much to her. It's still probably lucky that she lost them during apotheosis, however, as skills like Pride will burn up your soul even if you can counter the personality effects to some extent.
  • The Immortality skill sounds great, but Kumoko quickly realized that it's basically impossible to really obtain and people would chase it their whole lives but fail to get it. Even if someone does manage to learn it, if you're incapacitated with no self healing you'll stay that way forever. Even with self healing, you still can't move until you recover, meaning the combat practicality is basically nil: Your enemy can dispose of you as they wish or just keep smacking you back down forever. Plus there are at least two ways to kill someone immortal anyway.
• Screw This, I'm Outta Here
  • Kumoko thinks it's entirely natural for her to run away from an opponent who outmatches her.
  • Shiraori responds to delicate social situations by walking away or, if it follows her, teleporting away. She also attempted to leave the planet after becoming a god but was convinced to stay due to warnings about the dangers of doing so, an offer of divine patronage, and tasty food. The last item decided it.
  • Potimas had a UFO prepared in case he needed to leave the planet. Shiraori caught it easily. He'd originally planned to do this when the ancient civilization was on the verge of collapse but decided to remain when the Skill System was created.
  • The dragons left the planet rather than continue to fight and lose against Sariel.
• Screw You, Elves!: Both the Pope and the Administrators loath the elves. While in the web novel the only developed elves we see are Potimas and Oka-chan, in the light novel we see that even the rank and file are completely racist pricks that within five minutes have Shun's party wondering if they're even worth defending. Which makes their genocide more palatable.
• Sea Monster: The ocean is overrun with water drakes and dragons to the point that even fishing on the coast is near-impossible without encountering one.
• Seductive Spider: The series introduces us with Ariel, the Origin Taratect and Kumoko, who becomes an arachne & eventually becoming a goddess named Shiraori. The Puppet Taratects counts too, after Shiraori transforms them.
• Seiza Squirm:
  • Shiraori punishes Sue by tying her body into seiza posture. As she'd never sat as such before she was in tears by the time Shiraori released her.
  • Combined with Pose of Supplication. Sophia is cursed by Shiraori to call her Master or she'll face either punishment before her. The origins of the curse differs in the medium. In the light novel, Shiraori cursed Sophia using her god powers due to an incident in the demon academy, while in the Web Novel, Shiraori accidentally cursed Sophia after being drunk and has no way to undo the curse.
• Senseless Sacrifice: "D" points out that Sariel's original plan to save the world by being converted into MA energy and directly injected was flawed on multiple fronts. The equipment wouldn't have worked properly, Potimas was almost certainly going to siphon off the energy, and there was a good chance the planet would reject the energy and die even faster.
• Sequel Hook: The anime ends with Demon Lord's party on a journey to kill Potimas.
• Serial Escalation: Kumoko starts off barely surviving against the various monsters in the labyrinth, forced to rely on webs and ambushes. As the story progresses she moves to hunting larger and larger monsters, then to hunting dragons, and then to taking on the Demon King and Administrators before becoming one herself. At which point she sets her eye on destroying the Skill system.
• Serious Business
  • When Shiraori manages to defeat "D" in the first round of a fighting game but loses the second, "D" gets fired up and starts drawing on her divine powers to win the tie-breaker. Unfortunately for D, this allows Meido to find and apprehend her.
  • Shiraori regards simply talking as this, using all her clones (that are scattered across the world by the way) to help her make sentences.
• Seven Deadly Sins
  • In the form of Skills, either earned from a corresponding basic skill such as Anger or purchased with skill points. All are very powerful and dangerous as they grant the user "Ruler" status along with immediate rank 10 Skills. They also have a tendency to warp the user's soul. Shiraori is trying to steal the "Ruler" authority for as many of these as possible.
  • The skills above are only really achievable if said person struggles with said sin. Sophia has always envied and resented the people around her while hating herself while Wrath always struggled with controlling his temper and with a kneejerk reaction of solving problems with violence. The main character, meanwhile, has severe issues with three deadly sins: She displays much of the laziness, apathy and lack of empathy embodied by Sloth and eats enough food for dozens of people and typically keeps her power for herself. Pride is a more complicated case: She feels it's a virtue she has to live up to for her own sense of self worth, but often struggles with self esteem issues. On the other hand, she also tends to assume she knows better than everyone else and frequently makes their decisions for them even when she knows she's making wrong choices.
• Seven Heavenly Virtues
  • The counterpart to the Sin series, they're just as game breaking and dangerous to the user.
  • While sins as mentioned in the entry above often involve behavior destructive to the people around them, those who shows affinity for one of the heavenly virtues often display self destructive behavior as they obsess with these virtues. Shun, for example, shows absurd amounts of mercy and willingness to sacrifice his own well being even when it seems quite obvious that such behavior is not helping in the slightest. Oka-chan, meanwhile, is so focused on giving everything she has to her students (charity) that she completely neglects her own emotional well being and throws herself into mortal danger on more than one opportunity, even if she doesn't have to.
• Shaped Like Itself: A lot of skills like Divinity Area Expansion don't say anything helpful in their descriptions: For example, Divinity Area Expansion: Expands the Divine Area. Gee, thanks. Maxing out Taboo, on top of its downsides, also appears to expand how much certain skills reveal about themselves.
• Ship Sinking: Shiraori has three prominent male characters around who are all quickly ruled out. Blow is killed off before we learn he had a crush on her and thus we know not to get invested, Wrath's reaction is basically 'ew no' while Gyurie thinks she's interesting to talk to but absolutely not romance material. Also, he's in love with someone else already.
• Ship Tease
  • So far as Shiraori can tell, Katia is the heroine of Shun's tale, though she finds it kind of annoying. She even uses the power of love to break free of mind control and gets a princess carry afterward. Go die, normies!
  • Slightly Averted; Both the previous Saint Yaana and Julius have feelings for each other, in which his party members go out and support it, but Julius is hesitant in reciprocating due to the risky lifestyle of being a Hero Title holder.
  • Sophia and Wrath have a weird slightly shippy relationship, going so far having Sophia flat out proposition him in the middle of an argument. He turns her down, though.
  • The adventurer duo of Kunihiko Tagawa and Kushitani Asaka as both are childhood friends in their previous and reincarnated lives, with both admitting that if not for each other, they would been broken a long time ago. Merazophis even wishes for both of their happiness during their conclusive "fight".
• Shoot the Dog
  • Shiraori's main goal is to shoot the dog that everyone else has been trying their best not to notice. Thanks to the irresponsible behavior of others, she and Ariel are forced to plan widescale massacres in order to prevent the actual destruction of the world and the soul collapse of everyone on the planet because everyone before her was unwilling to make the kind of hard choice that Sariel wouldn't like. The death (or worse) toll if she doesn't shoot the dog is estimated to be at least 25% of the population, possibly higher up to and including everyone on the planet if the situation destabilizes or is even stalled much longer..
  • Potimas creates clone bodies he can act through by placing a tiny piece of his soul inside them to act as a controlling parasite. Shiraori figures she could maybe remove one or two but anything more is beyond her and is only a guess to begin with. Given how dangerous Potimas is, she elects to simply kill them one by one, including arranging for Hugo to target the infected when he begins his coup because otherwise Potimas could have destroyed several countries at once by turning their leaders into puppets.
  • Locked in a fight against an unstoppable robot powered by souls, Ariel destroys those souls with Soul Break because she has no way to free them, especially in the middle of a fight. These souls were presumably innocent people once, but now they've basically ceased to exist because of Ariel.
• Shout-Out
  • As an otaku, Kumoko's inner dialogue makes a large number of references ranging from Fate/stay night to JoJo's Bizarre Adventure.
    Shiraori: [paralyzing Wrath] King Crimson! Not quite the same though.
  • She also declares that you would have to be from the super vegetable planet to be able to break her threads.
  • Of course, there is this gem in the second light novel.
    Kumoko: If a little white demon came up to me right now and said, "Make a contract with me and become a magical girl," I'd totally say yes at this point. But then I'd have to get rid of him afterward, of course.
  • In the manga, Kumoko pictures herself as a Saiyan warrior when she obtains the Analysis skill, and when she obtains the 3D Maneuvering skill she pictures herself wearing a Survey Corps uniform and performing the military salute from Attack on Titan.
  • When cornered by the Queen Taratect in Chapter 46.2 of the manga, Kumoko compares the situation to Dark Souls — with a panel showing a bloodied spike-trap overlaid with the words "YOU DIED".
  • In episode 3 of the anime, Kumoko says that if she levels up Thread Control enough, she'll be as good at web-slinging as New York's Friendly Neighborhood Spider. Complete with an Imagine Spot of a red-and-blue Kumoko swinging through Manhattan. Doubles as an Actor Allusion in that Aoi Yūki voiced Spider-Gwen in the Japansese dub of Spider-Man: Into the Spider-Verse.
  • In episode 6, when Kumoko fights her first Elroe Gunerave, she lets out a Tarzan yell while web-swinging to avoid its flame-breath.
• Silly Rabbit, Idealism Is for Kids!: Shiraori and Wrath both scorn Shun's more idealistic position when it comes to the necessity of violence. However, while both of them are highly sympathetic and it seems like there may have been no other options, there's a lot of wiggle room for both of them to be wrong and Shun to have been right all along. Namely, there are some obvious holes in Shiraori's interpretation of the world and she could at least be doing a far better job than she is to keep people safe, but she doesn't care. Also, Wrath's former master and Hugo were not entirely unsympathetic people once you truly understand why they behaved the way they did. A decent attempt at communication may (or may not) have been able to resolve both situations peacefully. Wrath's namesake flaw comes in him not really caring whether someone is redeemable because he sides with the victims who want vengeance.
• Sinister Scythe
  • Zoa Ere, a pitch black spider monster with a reputation for being sinister and a bringer of destruction, has had its front legs modified into scythes instead of just normal claws. They're also so sharp that Kumoko thinks they should make a *ting* noise when she looks at them.
  • In the light novel, Kumoko wields one after evolving into an Arachne by cutting up one of her scythe legs as a countermeasure against Potimas after seeing Ariel easily disposing him through brute strength in physical combat inside his Anti-Magic barrier and continues to do so after becoming a god. In the web novel, she simply shifts back into Arachne form when she needs a bladed weapon as her front legs are still scythes.
• Single Specimen Species: There are no Arachnes at the start of the story and they've presumably never existed either. The same goes for the Zana Horowa, the species that seems most likely to evolve into it. When Kumoko reaches these levels she's the only example to ever live. Even when she uses the Spawning skill as a Zana Horowa she creates a different species line entirely, not more immortal spiders. It's unclear whether she could have made more Arachnes. Though in theory her clones should also be able to shapechange like she does and her true form does seem to still be a spider woman, so perhaps they do exist still. Just not within the System.
• Single-Stroke Battle: Nyudoz and Wrath's duel consists of Wrath cutting through Nyudoz's sword and neck with a single blow.
• Snark-to-Snark Combat: Meido and D frequently engages in this type of conversation in the "Teach Us, D-sensei" chapters.
• Space Cold War: It's a background detail of the setting that one of these is currently going on. There are multiple clans of gods, all of whom seem to view each other as rivals or enemies. One important trio has hit something of a standstill: The dragons, the angels and the demons don't openly fight each other anymore due to a roughly even balance of power. Because of this standoff, younger gods don't have the chance to fight anymore like they did when the gods were fighting openly.
• Spared by the Adaptation: When Shun's group is fleeing the kingdom, they choose not to make the attempt to save Katia's parents with Katia herself arguing that there isn't time. In the light novel it's not a problem because they're with Leston's group and are therefore able to be killed and resurrected to shed Potimas' soul parasites safely. Or "safely" if you prefer. Afterwards, they're promptly put on a bus when Katia bluntly tells them they have no way of stopping her from going to the elf village with Shun and are left behind.
• Spectator Casualty: Blow blocked Julius' attack spell to shield Shiraori and the surrounding demons, mistakenly thinking she was weak.
• Spider Swarm: Shiraori has created a swarm of spiders which are basically clones of her which she uses to perform different kinds of functions like spying, hacking the system and taking care of her pocket dimensions and all of them basically have a scaled down version of the original abilities.
• Spider People: The special "Arachne" evolution has a human upper half stuck on the body of a giant spider. None of them actually exist in the world because monsters are unlikely to meet the class qualifications for the lower stages and even on the rare occasions one of the earlier stages does show up they tend to accidentally kill themselves. Even the evolution before it, Zana Horowa, has never actually been seen in the world. To evolve from that into an actual Arachne requires the holder to have the Pride title, which really indicates quite well what they would probably be like if they had ever managed to appear. The light novel bio page for Arachnes indicate that they have never been seen and that their existence is basically unconfirmed with Kumoko being the only known sighting, but she wasn't well documented before vanishing.
• Spoiler Opening: The anime's opening credits show not only various characters from later in the story like Ariel, Sophia, Wrath, and Gyurie... but also various major events from later in the story, including Hugo trying to kill Shun, Julius's death, Kumoko evolving into an Arachne, and Kumoko undergoing apotheosis as D watches on. Also, while the anime, like all other versions of the story, goes to great lengths to mislead the viewer into thinking that Ariel is a future version of Kumoko, the season two opening blatantly shows the two of them fighting each other, spoiling the reveal for anyone who hasn't figured it out already.
• Square-Cube Law: Discussed. When Shun reads about the legendary monster Fenrir from a book and how large it is, he asks his attendant Anna how it even manages to support its own weight with its size. This introduces him to the concepts of stats and skills, both of which offer greater strength than would normally be physically possible. Basically, the only reason it could grow to that size is because it's magic.
• Standard Evil Empire Hierarchy: The first appearance of the Demon King showcases the entire organization, though some of the roles aren't clear until later.
  • The Emperor: Ariel is the current Demon King, a being of immense power known as the Oldest Divine Beast and the Origin Taratect. She has the appearance of a young girl, but actually has spider powers. She's about as strong as you can possibly get within the System.
  • The Right Hand: Ariel refers to Shiro as her "greatest masterpiece" though she played no real role in her birth or rise to power, even coming into conflict with her at one point. Shiro herself is much stronger than Ariel and the one truly in control.
  • The General: There are ten generals, six or seven of whom are basically 'normal' people. They're all quite sympathetic because none of them want the war besides the fifth general, who is both the least important and only supporting it because he's blindly loyal to anyone who serves as the demon king.
  • The Security Officer: Shiro is assumed by most to be a special forces/intelligence specialist due to her impressive intelligence gathering capabilities and use of the rare Space Magic.
  • The Oddball: Gyurie is the leader of one of Ariel's demon armies, but his troops don't take part in the battle and Gyurie himself is only in a watchdog position.
  • The Evil Counterpart: Eight demon general Wrath was once known as Sasajima Kyouya, the best friend of Shun. He has a strong sense of fair play and a quick temper, though he tries to keep it under control. Unfortunately, his backstory since reincarnating has made him incompatible with Shun's ideals. Notoriously brutal among the other generals.
• Standard Japanese Fantasy Setting: The series is set in an RPG Mechanics 'Verse that features morally-complex gods, a Hero, demon-lords, religious and abyssal magic, and the corruption and destruction of its denizens' souls in a cycle of reincarnation. Later revelations also indicate that the world is slowly dying thanks to overuse of The Lifestream — a problem that drives the underpinnings of the setting. In a parody of traditional isekai, the protagonist is reincarnated as a weak spider-monster in a labyrinth instead of as the Hero — with that honor eventually going to one of her classmates. Humans live in medieval-style kingdoms, most elves live in a Hidden Elf Village, and Monstrous Humanoid species like goblins and ogres live in isolated villages and are often regarded as being just another type of monster.
• Standard Sci-Fi Army: That being said, the ancient civilization has access to very advanced weaponry, though it wasn't enough to stop the rampaging dragons. Potimas studies these weapons to create the Glorias, though they become useless once Shiraori get serious and even has a UFO in case he needs to escape the planet. In Volume 7, it takes the combined might of 5 powerhouses in the story in Kumoko, Ariel, Dustin, Potimas and Gyurie to take down said weapons.
• Stat-O-Vision: The Appraisal skill provides this, once its level is high enough.
• Stealth Hi/Bye: Shiraori has a habit of doing this with Transfer, sometimes appearing just long enough to leave a poorly-phrased message before leaving.
• Storm of Blades: Wrath stores his extra weapons with Spatial Magic and can unleash them in a rain of fired swords. Shiraori compares him to Gilgamesh.
• Sufficiently Analyzed Magic: Potimas determined there must be rules governing magecraft if he could only deduce them. Which he promptly did. Shiraori then went and analyzed his antimagic and proceeded to neutralize it.
• Suicidal Overconfidence: In the middle of Kumoko's fight with Alaba, the labyrinth wasps are still trying to sting her even as giant laser beams and fireballs are flying everywhere. They're nothing more than a minor distraction to her and Alaba also blasts them away without paying any attention to them.
• Sunk Cost Fallacy: Wrath stays with Shiraori not because he thinks her plan is good - he's highly conflicted on that and abhors her methods - but because he feels it's the only way to give meaning to the large number of deaths he's already caused.
• Super Breeding Program: Potimas created the base stock of the Elf race by cloning himself multiple times. He then had those clones abduct outsiders and forcibly converted them into the same race. This allowed him to create a viable gene pool which could be expanded with the simple process of abducting yet more breeding stock.
• Superior Successor
  • After Kumoko lays some eggs in the labyrinth and reincarnating into one to escape Ariel, the eggs begin hatching as (relatively) tiny white spider monsters with stats that are the lowest seen in the story at a mere 3. However, they also have some minor poison, the ability to coordinate and a mindless devotion to mommy, so when hunting in groups they're able to take down much larger prey. When Kumoko sees them again a week later, they're already as strong as she was several evolutions later and every time she sends them out again to hunt for her they come back even more ridiculously strong. By the time the story hits the present day, the spiders now known as horo neias are monsters that even individually are on seemingly on par with dragons. Fortunately, they keep to themselves unless attacked because one order they received before attaining independence was that they shouldn't kill Ronant, leaving them neutral towards humans in general. They also really love mom and cuddle her whenever she comes to visit.
  • While the strength of the horo neias is somewhat a matter of speculation, Shiraori considers her clones weak because it would take three newborn tarantula sized spiders to take out a dragon.
• Super-Persistent Predator: The monkeys confuse Kumoko for this very reason: She's not much good as a meal given how poisonous she is and is more than capable of defending herself, making it clearly not worth the effort for such a small amount of food. However, it's not about eating her, it's about avenging the monkey she killed earlier. The sheer persistence of the Anogratch monkeys is why they're generally known as Revenge Monkeys and in large numbers can be one of the most dangerous monsters around. They will stop at nothing to kill anyone that injures a member of their group.
• Sure, Let's Go with That: Shiraori often doesn't bother to correct people's misunderstandings if they're convenient to her. For example, she lets all the reincarnators think she's Wakaba Hiiro because the truth is way more complicated and she hates speaking.
• Surprisingly Realistic Outcome: When you Reincarnate in Another World, even if you're given an overpowered special ability, reincarnation by its nature means you start out as a helpless baby just like everyone else. Some of the reincarnators died as infants without even having the opportunity to use their powers.
• Take a Third Option: Shiro thinks up two plans that can be used to save the world and Dustin agrees on that basic assessment. They both choosing opposing plans and know that there will be conflict as soon as their mutual enemy is dealt with. Upon learning of the situation, Shun finds he can't decide between the two plans: Dustin's is correct from a utilitarian point of view but is rather cold hearted and willingly makes sacrifice of many innocent people including Sariel and Gyurie so he can't quite bring himself to side with his plan. He wishes there were a third option, but Dustin assures him there is not and he knows that Shiraori doesn't know of a better plan either because she'd use it if she did. Whether there really is no third option is unclear: He's the hero and it's the hero's job to find impossible solutions.
• Take Up My Sword: When the Hero or Demon Lord dies, the skill is automatically awarded to another individual to take over the role. There exists a secret tracking system which makes people previously defeated by the Hero more likely to become Demon Lord.
• Taken for Granite: The Petrification attribute allows this, usually seen with the Evil Eye. Basilisks possess this naturally, which resulted in Kumoko spending a while with a stone foreleg. Though dangerous, Kumoko eventually decides it's a bit too slow to be practical because while it's crippling in the long run, in the short term it's not that much of an advantage.
• Tangled Family Tree: Thanks to Potimas's various experiments in genetic engineering and cloning, and "D" playing around with the monster generation features of the System, quite a lot of disparate characters are technically related. This includes Kumoko, Ariel, Oka, Wrath and Potimas at the very least, with Potimas being Ariel and Oka's father, Ariel being Kumoko's grandmother, and Wrath being the far removed descendant of copies of Ariel's long dead brother Gob. And just to complicate things more, the goddess Sariel is the adoptive mother of Ariel, the first Hero, the first Saint, Gob, and all of Potimas's other first generation of genetically engineered children. And "D" is Kumoko's mother from a spiritual perspective, or Kumoko is her clone, depending on how you want to look at it.
• The Team Normal: Anna is this for Shun's party, being a relatively sheltered maid. She's less skilled in combat and her stats are much lower than anyone else, but she never quite reaches the point of being The Load.
• Telepathy: A skill allowing mental communication which Kumoko ignores as there's nobody to talk within the Labyrinth. D and Gyurie read her mind whenever they meet her.
• These Are Things Man Was Not Meant to Know: The Taboo skill explicitly warns that its level must not be raised and is only available to those who commit horrible acts. Reaching Level 10 allows the user access to a maliciously edited history of the System, memories of your past lives, and various details ordinarily inaccessible to mortals. Accessing this information induces extreme feelings of nausea and guilt, sufficient to drive normal mortals to insanity.
• Thinker Pose: In the manga version Kumoko does the pose in chapter 18 while pondering her latest evolution opportunity, substituting her own spider abdomen for the statue's seat.
• Third Line, Some Waiting: After the B-team meets up with a previously unknown C-team, the B-plot is put on hold. The story instead focuses on bringing the A- and C-teams up to date.
• This Is Something He's Got to Do Himself
  • The reason Shiraori did not intervene to save Blow's life was so he could maintain his pride, something she feels is more important than surviving.
    Shiraori: I can save [Blow]’s life. However, at the same time that is a deed that will stain the hoodlum’s pride. It’s up to each person which one to choose, but I choose to take pride. Even if the hoodlum dies as a result.
  • Ariel refuses any help from Shiraori when she goes to face Potimas as she personally wants to kill him.
• Thousand-Yard Stare: Shiraori very pointedly ignores the fact that all of her subordinates eventually gain this due to her heavy-handed methods.
  Shiraori: [regarding a soldier she "reformed"] It’s just your imagination that his eyes look like that of a dead fish.
• Throw-Away Country: During his rampage, Wrath manages to kill nearly every living creature in an entire nation. The last time it was mentioned was when Shiraori let Gyurie think it was necessary to stop the world from collapsing. It wasn't, but the place didn't serve its intended purpose anyway so having them all die doesn't really hurt anyway and has some other side benefits to the plan.
• Throw It In!: In-Universe this is the reason for the Demon King and Hero existing. When the first human-demon war broke out, a "hero" and "demon king" rose to power of their own accord to lead the two sides. D thought it was amusing and added the unique skills.
• Title Drop: By Kumoko herself, explaining her continued monstrous eating habits even after her evolution into a humanoid form.
  Kumoko: I'm a spider, so what?
• Tomato in the Mirror
  • Kumoko / Shiraori eventually susses out that the inaccuracies and gaps in her memory are the result of her not being Wakaba Hiiro. Shiraori was an ordinary spider that died in the classroom. Instead, The Evil God D was the real Wakaba. D, who had been skipping out on work in The Underworld, then gave the spider part of her memories and reincarnated it in a place she expected it to die, in hopes it would confuse her bosses enough she'd get to slack some more. Instead, Kumoko survived, which entertained D so much she started helping the spider out with the Wisdom skill and protection from Administrator Gyuriedistodiez.
  • Kumoko had a variant of this when she learned about Administrator "D" and what this meant about the Skill System.
    Kumoko: "This world is pretty fun, it's like a game"? I'm an idiot. If this world is like a game then I'm not the one enjoying it. It's the Administrators who are watching it.
• Tomato Surprise
  • The contents of Taboo explain a great deal about why Kumoko behaves the way she does and especially about her interactions with the Administrators, but it is kept secret from readers for a long time.
  • Kumoko's plan to usurp the Queen Taratects and Demon King are not revealed until after the first Queen is consumed, which explains a great deal about the change in narrative such as the near-absence of the Parallel Wills.
• Took a Level in Badass: When a unit hits a certain level they have the chance to evolve into a stronger form. This resets their stats backs down but comes with higher stats than the previous form at an equivalent level and several new skills. For weaker monsters, this occurs at level 10. Stronger ones need to get to 20. Some evolutions are even more difficult.
• Too Awesome to Use: The Hero and Demon Lord's sword, which are crafted by D, are very powerful weapons that can kill anything, even Gods. They are guarded by Gyurie's dragons and only the ones holding the Hero and Demon Lord Titles can wield them. The weapons themselves fall into Awesome, but Impractical territory though, as they are one time use only and it acts as more of a Doomsday Device due to it consuming MA energy.
• Too Powerful to Live: An In-Universe example. In the novels, Potimas gains access to the Student Roster skill due to his daughter, Oka, and has gathered most of the Reincarnations save Kumoko, Wrath, Sophia Keren, and Sakurazaki Issei. In the case of Sophia and Sakurazaki, this is because both are way too powerful to be allowed to keep alive in his mind; Sophia has the Vampire Progenitor skill, allowing her to No-Sell the traditional weaknesses of her race, while Issei has the Dungeon Creation skill, which would have allowed him the ability to create more dungeons or expand them if desired. Sophia is lucky enough to be saved by Kumoko while Issei is killed. Potimas has also considered killing Wrath due to how powerful he has become after acquiring the aforementioned skill but was derailed when Ariel's party subjugated Wrath.
• Training from Hell
  • When Shiraori decides to make Sophia stronger, the training is kept at juuuust below the level that won't kill her and includes things like being forced to eat poison, walking from place to place as a toddler until she's at the point of collapse and later even harsher training as she becomes capable of handling it. It works, too: Despite being still only being level three she's more than a match for Wrath, who has evolved multiple times and has sky high stats. She later offers suggestions to Sophia and Wrath on how to protect themselves from the Sin titles with the Detection method being marked specially as 'this one might kill you.' While Wrath's reaction is unimpressed Sophia realizes that she means it from Shiraori's own point of view, meaning it's way more dangerous than anything even she had to go through in terms of training. The two of them choose to literally attack each other's souls instead of going through that level of horror show.
  • She later subjects Felmina and the soldiers under her command to this. She mentally refers to it as "tormenting" and insists it has no connection to the dead look in their eyes.
  • Merazofis subjects himself to this in order to become even slightly stronger for Sophia's sake.
• Transferable Memory: While pondering her reincarnation, Kumoko muses a more unusual explanation might be she had the memories of somebody else who is still alive transplanted into her. She later learns this is true, as "D" implanted a modified set of her human memories into Kumoko.
• Translator Microbes: In one of the "Teach Us, D-Sensei!" chapters, the reincarnator special skill [N%I=W] functions as this. It's the reason why the System messages, Appraisal results and the Voice of Heaven speaks Japanese instead of the usual planet language.
• Trailers Always Spoil: The anime heavily implies that the current Demon Lord is a current day Kumoko. The Second Opening completely spoils that it isn't the case when it shows Kumoko and the Demon Lord fighting.
• "Truman Show" Plot: After learning about "D", Kumoko speculates the point of the Skill System is to entertain the Administrators. Or at least "D".
• Two Lines, No Waiting: The series also has side chapters that focus on a different set of reincarnated students, which plays out more like the traditional Reincarnation light novel story. What's amusing is watching the B-team have difficulty against monsters that Kumoko was hunting for food years ago.
• Ugly Cute: In-Universe, Shiraori wants to ask the Remnants of the Nightmare what they were babbling to Shun about but the moment they see her they all run up and start cuddling her with the clear attitude of 'we did a good job, mom! Praise us!' so she can't bring herself to scold or question them.
• Unbreakable Weapons: D blesses Kumoko/Shiraori's scythe to be indestructible within the confines of the System and even has an auto repair/regeneration ability just in case someone "did" manage to damage it. Kumoko even speculates that even a full on attack by Ariel will not even mark a dent on her scythe and uses it to her advantage to parry the tank fire and easily destroying the said tank, which amazes Ariel herself.
• Underestimating Badassery
  • When Ronant returns to the labyrinth to commit suicide after hearing that the Nightmare was killed by Ariel he runs into Kumoko. While he recognizes both spiders as being her he's only really interested in the white main body, figuring the black spider next to it is just a normal taratect. It is, in fact, a reborn infant Queen Taratect, the most dangerous kind of monster seen in the story.
  • Both Hugo and Shun consider the mercenary duo of Kunihiko and Asaka as slightly weaker and below them due to their lower stats in comparison to theirs. But in the Demon side, both Sophia & Wrath agree that they're particularly bothersome and is actually considered by Shiraori as the strongest amongst the human reincarnations that they could actually outmatch both Hugo and Shun, if not for the latter's Hero Title.
  • Inverted in Shiraori's fight with Gyurie. She spends the fight confused as to what he's doing and being extremely on her guard against hidden tricks or secret moves, but by all appearances he's actually a pretty crappy fighter even if he's far more powerful than she is. He knew going in that he didn't stand much of a chance and views her overestimation of him with resignation. Especially since if she had been aware of the true power balance between them she might have been overconfident and made some kind of mistake.
• Underground Level:
  • Kumoko was reborn in a massive undersea labyrinth that connects two continental landmasses. It took a long time and many powerups before she can muster enough strength to reach the surface safely.
  • Ariel and Kumoko's party first encountered the G-Fleet weaponries during their exploration of the underground ruins in volume 7.
• Ungrateful Townsfolk: According to Ariel, at least. Sariel was the only being who stood between the people of the planet and complete annihilation during the ancient civilization's fall. Despite this, the people eventually accepted the solution of sacrificing her, something she agreed to first, to save themselves. In the present day, knowledge of her sacrifice has been deliberately suppressed apart from followers of a relatively small religious sect, which faces constant persecution as a result and is the direct target of an attempt at straight up genocide to hide the truth.
• Unique Protagonist Asset: The reincarnated class received three bonuses compared to normal people. "D" felt a little guilty about getting them killed so tried to make sure they'd have an advantage.
  • Aside from Kumoko, they start with a massive number of skill points compared to most people. This is actually due to their souls being stronger than those that are being recycled by the System.
  • The exclusive [n%I=W] skill allows their HP and body to full recover on gaining a level rather than requiring healing. It has a number of other side effects like translating the System's level up/skill acquisition notifications into Japanese for them.
  • Either a completely unique skill or high-level skill that suits the individual's personality, such as Kumoko receiving the speed-boosting Idaten and Sophia being a True Ancestor.
  • Kumoko herself has the unique ability to use Appraisal freely, something that usually causes fierce headaches and physical illness, and other mental skills that are usually too dangerous. This is due to possessing a fragment of D's soul, which gives her a higher affinity with the System and greater resistance.
• Universal Poison: Lampshaded and played with. Poison generated by skills effects all enemies equally based on their Poison Resistance skill. However as Kumoko finds out after her ascension, "poison" in the system is really just water or other materials with the poison attribute applied to it, making it universally harmful to living things in the System. Later, Potimas averts this by finding a way to weaponize carbon monoxide, which still exists and ignores poison resistance on account of not being what the system considers poison.
• Unknown Rival: Kunihiko feels like this due to Merazofis, the man he wants to kill to avenge his family, seemingly overlooking his existence entirely. In fact Merazofis is well aware of him but can't kill him due to Shiraori making reincarnators off-limits.
• Un-person: The Divine Word religion has spent generations stamping out all knowledge of Sariel's existence, with only goblins and the Goddess religion still remembering some parts of her history.
• Unwanted False Faith: Kumoko set up near a village hoping to lure in and eat some adventurers or soldiers. Instead she was mistaken for the Goddess' spider servant and ended up healing more people than she ate. She grudgingly accepted it until people start using her as an excuse to be dicks, after which she just left.
• Unwitting Pawn: The previous Hero and Demon King were actually working together to achieve peace, which is a good goal so long as you don't know the complicated backstory. Unfortunately for everyone, Potimas told them that the true enemy was the Administrators. They didn't 100% take him at his word, but filtered everything they learned from Gyurie through that and decided he must be the real enemy after all. They attempted to kill him, Sariel intervened to send the attack at "D" and the end result was that twenty five children, one teacher and one spider were killed in a strange explosion. And that's just the start of the nasty consequences of their foolish attack.
• Useless Useful Spell:
  • Appraisal is an incredibly useful Skill... once leveled. When first learned it returns barely any information and causes massive headaches, which only get worse with usage and more levels. As a result very few people learn or level it, instead relying on Appraisal stones or a handful of families that specialize in it.
  • Immortality turns out to be this for Kumoko. As she quickly realizes, while it technically keeps you *alive*, it would still leave you at the mercy of whoever defeated you, potentially leading to a Fate Worse than Death or reducing you to Sealed Evil in a Can. On top of this, the one serious fight she gets into after gaining it is against an opponent with magic capable of killing her permanently anyway, and in order to continue progressing past that she has to undergo apotheosis, causing her to lose it along with all her other skills.
  • Status spells and effects are a good way to get around being weak early on, but at higher levels most opponents have increasing resistance to them. Since Kumoko ended up building herself offensively as a quirky status affliction specialist, this puts her at an increasing disadvantage with her normal strengths as she gets stronger. As a result, she switches over to using magic more directly.
• Vengeance Feels Empty: Kumoko hunted Alaba in order to avenge her wounded pride, but seeing his composure in the face of death infuriated her as it was contrary to her own beliefs. While she killed him in the end, Kumoko reflected she ended up in an even worse mood.
• The Very Definitely Final Dungeon: The Great Elroe Labyrinth is the world's largest dungeon, spanning the ocean between the continents, filled with the deadliest monsters on the planet and the resting place of the comatose goddess Sariel. It even literally becomes the final battlefield for the conflict between Dustin and Ariel's factions as Ariel races to play defense without her strongest ally, the ability to defend herself and numerous ancient dragons gunning for her.
• Victory by Endurance: Kumoko defeats Alaba by using Sloth to slowly drain his stamina until he's too exhausted to fight.
• Villainous Breakdown: Potimas goes from comfortably smug and mildly sentimental to screaming in panic when Shiraori gets serious. By the time he dies, he's yelling unintelligibly.
• Villain Protagonist: Not just in the sense that we follow a killer spider-monster for the majority of the series, but the 'demon lord' and her 'evil hordes' are committing the 'evils' they are because it will save the world, albeit still killing a whole bunch of people.
• Violation of Common Sense
  • So many times with Kumoko which allows her to gain many skills, even unconsciously assaulting her body with magic attacks to build resistance. When she sees someone try to emulate her she's absolutely baffled.
  • Her protege, Sophia, has also started thinking like this thanks to Shiraori's influence and even Merazofis has developed a similar mentality.
• Vitriolic Best Buds: Sophia and Felmina eventually strike up a weird, hostile kind of friendship. Or at least as much as a sociopath and one of her many victims can be friends. Sophia even secretly wants to apologize, but only when she's not being forced to do it because that would be insincere and she does realize that she's wronged Felmina.
• Wall Run: The 3D Maneuver skill allows this. The skills is redundant for Kumoko as she can already do this as a spider.
• Weak, but Skilled: Compared to monsters, humans and demons are quite weak and have to get by with better tactics and a higher variety and quality of skills. Unfortunately, this only gets them so far not just because of how powerful monsters get but also because higher ranked monsters like dragons and high tier taratects are fairly intelligent themselves.
• What a Senseless Waste of Human Life:
  • Julius ponders this after killing Blow, given that both had brothers at home they were thinking of. When seen from Shiraori's perspective hundreds of chapters later, She has the exact opposite view, as Blow died standing proud, fighting for what he believed in and free from the interventions of gods like "D" and herself.
  • Shiraori truly wished that she didn't have to massacre the Demon's First Army because of Sariel messing with her plan.
    Shiraori: Sorry, Argnar. In order to grant the future you wish for the demons, the only option was to abandon you.
• What Happened to the Mouse?
  • The last time Cyrus is ever seen in the web novel is Hugo making it clear he was nothing but a pawn and then seemingly going off to do his own thing in the elf village. So presumably he's still ruling the kingdom? The light novel ties this up by having him end up partially mindbroken due to Hugo using his Charm too heavily on him while making it clear his betrayal was not coerced and therefore he isn't worth Shun's concern. In the web novel it's eventually mentioned in passing that he and his mother are currently attempting to hold control of the country and so close to a civil war that despite their own interests aligning with Shun they still won't be able to send any meaningful assistance.
  • The buildup to the climax of the story starts hinting at Dustin having some kind of ultimate plan extending beyond the final battle, likely including an attempted genocide of the demons and some kind of shady plans for the reincarnated students too weak to defend themselves. However, the conclusion to the story doesn't address this much except noting that Oka-chan did secure the students, taking Shiro's side in the process.
• What the Hell, Hero?:
  • Basgas shouts down Shun first when he uses Appraisal on the Water Drakes while entering Elro Labyrinth and again when he talks to the Remnants of the Nightmare. Either move was incredibly reckless and could have gotten everyone killed.
    Basgas: I told you, lad! I told you that your comrades could die because of your thoughtless actions!
  • Shiraori becomes openly angry after Sariel interferes with her plan to delete the Hero System by making Shun the new hero, shouting her down for wasting the precious energy demons and humans sacrificed their lives for just to get in the way of the very people trying to save her.
    Shiraori: Just how much do you have to interfere until you’re satisfied! Just how badly will you crush people’s feelings until you’re satisfied! Do you really want to save people’s lives that much!? Why can’t you understand that is exactly what is driving people to their deaths!?
  • When some of the whinier students bitch to the adventurer duo about how much fun they were having in the outside world while they were stuck in the village, Kunihiko explodes that gee it sure is fun to break multiple bones every day and to have your family slaughtered and live for revenge against a man who you can't even hope to touch.
  • Wrath, the most moral member of Shiraori's group by far, is furious with Sophia not just because she was using her Charm abilities on other students to make it easier to feed off them but also because she pretended not to see anything wrong with her behavior.
  • When Wrath and Shun finally meet, Shun is appalled at Wrath having killed people and criticizes him for allowing his values to slip. Wrath accepts the point, but doesn't change his mind and this marks the point of burning a really serious bridge between the two of them. It's only afterward that Shun realizes he should have tried to figure out why Wrath does what he does before attacking him, but at this point there's no more time to talk.
• What Is This Thing You Call "Love"?: Shiraori doesn't really understand what she feels for Ariel, though it leads her to try her best to grant Ariel's dearest wish. This is likely due to her originally being a spider, and her human memories coming from D, who has No Social Skills.
• What Measure Is a Mook?: Despite the deaths caused by Hugo during the failed assassination of Shun, Oka-chan spares his life. This comes back to haunt her and Shun as it just makes him want revenge. Then Shun tries to spare him again due to Kindness influencing him. Everyone else disagrees and Wrath makes his opinion clear by killing Hugo.
• What Measure Is a Non-Human?: The story of Buirims and Wrath explore this trope, with Buirims failing to realize until it was far too late that his goblin slave was an intelligent being who had loved its family.
• Whole Episode Flashback: After the death of Potimas, an arc was dedicated to the ancient civilization and the events that led to the world's current state.
• With Great Power Comes Great Insanity: The Seven Sins and Seven Virtues skills give the wielder Ruler privileges and immediate level 10 Skills. However they also grant Taboo levels and warp the soul of the user until they are completely overcome by the skill. Kumoko got away with it because Patience had maxed out her heresy resistance, granting her immunity to the soul warping side effects. Mostly, anyway.
• World's Strongest Woman: Demon King Ariel is the strongest being within the confines of the System, with even her puppets being powerful enough to crush armies.
• Worthy Opponent:
  • Wrath develops Parallel Will due to the stress of fighting the Sword God Reigar and uses the small bit of control it grants to ask his name and give praise.
  • The dragons respect Kumoko for hunting and killing several of their number in fair combat despite starting far weaker than them, to the point where they're willing to oppose Ariel to keep her from annihilating Kumoko in what (they assume) would be an utterly one-sided stomp.
• Would Be Rude to Say "Genocide":
  • Goblins are viewed as dangerous monsters due to their aggressive behavior towards non-goblins and the fact they can be tamed. As such wiping out every goblin, even children, in a village is referred to as "subjugation".
  • The entire elven race is destroyed in the process of hunting down and killing Potimas. The only full blooded elf survivor is Oka-san. The main characters say it was absolutely good and necessary which might be a little questionable, but then again they aren't exactly claiming the moral high ground anyway. Notably, despite the elves all being clones of Potimas, his followers and indoctrinated captives, they're still clearly individuals who aren't in on the full story of what's going on. Most of them were genuine believers in peace and didn't know what long term peace would do to the world.
• Xanatos Speed Chess: As Kumoko's precognition and concentration powers increase, battles increasingly take on this flavor because she usually can't afford to take even a single hit. This is compounded with the dragons as most of them have similar skill sets for predicting the flow of battle.
• Yaoi Fangirl: Sachi Kudou, one of the reincarnated students, was this in her original life. With nothing else to do after being sequestered by the elves, she proceeded to convert most of the other female students to her "rotten" interests. The male student who speaks with their male elf guards is rather nervous regarding how they watch him. However, much to her surprise, she finds that in real life it just doesn't interest her and makes her slightly uncomfortable while all the other girls just eat it up, leaving her oddly isolated.
• Year Inside, Hour Outside / Year Outside, Hour Inside:
  • Shiraori makes pocket dimensions that slow down or speed up time to create prisons, storerooms, and places to talk.
  • Earth experiences only one year for every decade that passes in the fantasy world.
• You Can't Go Home Again: Shiraori offers to take Sophia home after the System is dismantled if she wants to go, which Sophia misunderstands to mean that everyone can go home any time they like. This is triply wrong: First, the System being dismantled is a requirement to leaving at all since the [n%I=W] skill binds the reincarnators to the world and the only way to ditch it is to die or become a god. Second, Shiroari offered it to Sophia because she's a friend, but actually taking someone along to another world requires so much energy that she cannot feasibly take more than about two or three people with her. Third, even if she could the students all died. More than a year has passed as well and everyone looks completely different from how they did before, up to and including an outright sex change. There's nowhere for them to actually go. Four students have even died again since then, so their souls have moved on as well.
• You Do NOT Want To Know:
  • When Sophia asks Shiraori a question about what she intends to do after the end, the conversation eventually turns to indirectly talking about D. When Wrath and Sophia trying pressing her for details, Ariel and Shiraori clam up because knowing about someone like D is just way too dangerous and unpleasant.
  • When Ariel unwisely gets Shiraori drunk, the latter starts pulling something out of personal dimensional pockets, snacking on them and giggling while staring into space. Ariel absolutely refuses to look too closely at what Shiraori is munching on or to ask her anything about it. We don't learn what it was either, but given that it horrified Ariel and that both of them are cannibals, it can't be good, even if the scene is played for laughs.
• You Have Outlived Your Usefulness:
  • Subverted. The first commander of the demon army is sacrificed when a Queen Taratect is teleported into the battlefield and dies thinking that Shiraori was disposing of loose ends, but she's actually furious because she had really wanted to keep him alive but Sariel screwed her over by refusing to allow the Hero title to expire, so Kumoko had to cause massive casualties to make up for the energy it took to do that.
  • One of Potimas's plans after gathering most of the reincarnations was actually him killing Oka as he has no further use for her before he starts experimenting on them.
• You Have to Burn the Web: Standard practice of adventurers in the labyrinth was originally to burn any webs they discovered. Kumoko was traumatized when as a weak infant her first home met this fate. When this happened with another home after she had become much stronger, she proceeded to annihilate the guilty party. Not long after standard practice became avoiding webs.
• Your Days Are Numbered: According to Oka's special skill, the students are all fated to die at certain points unless she does something. However, it's specifically noted to be flawed: Shun was supposed to die rescuing Leston, but escaped unharmed and successful. Also, for the majority of students who have skills, they're supposedly going to die from skill deprivation. This is only a problem for them if Shun succeeds. Shiraori intends to protect them all and, even if they die, will definitely shield their souls. And even if that fails, it's implied that D is sheltering the souls of all the dying students as well, even the ones like Hugo and the three students who died in infancy, none of whom Shiraori would/could have helped.
• Your Magic's No Good Here:
  • After becoming a goddess, Shiraori realizes that most of the Skill systems magic is a farce compared to actual magic. Most of the System spells are essentially programs that only work because the System registers they should. She has to start learning from scratch as some of the magic she uses has no non-system counterpart.
  • The spell used by the previous Hero and Demon King collapsed because the target was outside of the System. Without the System's assistance the spell was too complex for them to manage and exploded.
• Zerg Rush
  • A common response from various species of monster including Elro Ferect, Finjegoath and Anogratch, a lesson that Kumoko had to learn the hard way.
  • When stalling Gyurie at one point, Shiraori just throws a bunch of clones at him to waste his time. She herself doesn't bother to appear. From his perspective, the fight takes ten days to get through and leaves him utterly exhausted. Later, during her real battle with him, she has the clones rush him in a different way by having him devour the divine territory supporting him while otherwise keeping their distance. The spider clones gobble away at his power while he can't catch up to them. Just killing a few clones wouldn't matter anyway, so he tries to close on Shiraori and fails.
  • For the massive battle of humanity and demonkind storming the Elro Labyrinth, mages are blasting massive waves of taratects which are continually summoning their own minions. The small fry quickly die off before they can even reach but these kinds of tactics are noted to be only really limited by the upper ranks' ability to spend the time summoning them rather than actual numerical limits.

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