An unnamed male protagonist falls asleep at his computer playing a Massively Multiplayer Online Role-Playing Game, only to find himself in the body of his avatar, "Arc", equipped with its strongest armor and weapon from the game. Unfortunately, Arc's appearance was also changed to that of a special skin the protagonist bought: a full-body skeleton. Deciding to become Arc in this new setting, the protagonist sets off hoping to not draw attention to himself, helping others as he can, while finding if there's a way to undo his mistake of looking like a skeleton beneath his armor.
Has absolutely nothing to do with the character Skull Knight from Berserk.
Skeleton Knight in Another World contains examples of:
- Adaptation Deviation: The manga adaptation deviates heavily from the light novel after Arc and his friends save the city of Saureah in the Nohzan Kingdom from the undead army, with the following story arc focusing on Arc learning to master his Archangel Michael summon instead of making preparations to defeat the Holy Hilk Kingdom once and for all.
- Adaptation Distillation: The anime adapts the first three volumes of the light novel, and removes some minor story arcs and characters in the process.
- Adapted Out: The Hilk religion and its associated characters, such as Boran, do not appear or get mentioned at all in the anime.
- Attempted Rape: The bandits that attack Rita and Lauren in the beginning of the story try to rape them, but fortunately Arc shows up in time to intervene.
- Bash Brothers: Arc and Goemon clash to test each other's strength, and come to bond and respect each other. When attacking the Etzat Slave Market, Arc's Earth Magic and Goemon's Earth Ninjitsu amplify each other. After getting the last group of beastfolk to safety, Arc teleports back to Goemon, and their final joint strike destroys the Market completely.
- Boobs of Steel: Ariane is this, obviously, but the entire adult female elf population are all this. Her older sister and the female elven warriors are most definitely Ms. Fanservice, and kicks just as much ass.
- Crapsaccharine World: Despite the series being very bright and colorful, it does not shy away from the darker aspects of a medieval society.
- Cursed with Awesome: Being a skeleton works for intimidation, but not for anything else, as Arc finds out.
- Dem Bones: Arc is basically a walking, talking skeleton. The pontiff of the Holy Hilk Kingdom is eventually revealed to be one as well.
- Description Cut: When discovering the corpse of a giant basilisk, the soldiers comment that for a single person to perform such a feat, they'd have to be a god, or the devil himself. It then cuts to said "devil" Arc chugging down some beer. This trope is played again and again as our protagonist Took a Level in Badass, but continues to hide his real identity.
- Destructo-Nookie: Ariane got into a very noisy drunken brawl with Arc at an inn, wrecking some of the furniture in the process, leading the owner (and apparently the neighbors as well) to think they really got it on that night.
- "Do It Yourself" Theme Tune: Ponta's "voice" actress, Nene Hieda, is part of DIALOGUE+, the girl group that does the ending theme.
- Door Dumb: During an infiltration mission where Ariane and Arc have to enter a fortress, Ariane tries to push open a large steel door with no effect, it was revealed by Arc that they were actually sliding doors.
- Enemy Mine: After Arc, Ariane and Chiyome defeat Cardinal Palurumo Avaritia Liberalitas and the force of 100,000 undead he tried to use against the Nohzan Kingdom, King Asparuh of the Nohzan Kingdom and Count Wendly of the Salma Kingdom realize that their common enemy is the Holy Hilk Kingdom, and work with the elves and mountain people to defeat the Holy Hilk Kingdom in the light novel.
- Enslaved Elves: Humans will try to capture elves to sell as slaves. Females are usually sold as sex slaves to nobles, while the males are forced to impregnate noblewomen to produce children capable of magic.
- Evil Laugh: Arc, to the point where the opening even ends with him doing one of these.
- Fantastic Racism: Discrimination against elves and mountain people is actively encouraged by the Hilk religion. This was done because they could instinctively sense that the Hilk cardinals were undead no matter what disguise they took, but this is gradually being undone after they and the pontiff are defeated.
- Huge Guy, Tiny Girl: Arc is definitely bigger than his dark elf companion, Ariane, but there's nothing tiny about her. This trope is played even straighter when comparing him to Chiyome, who only reaches his waist.
- Nobody Here but Us Statues: While breaking into a slave owner's mansion, Arc poses as one of the armored statues, with Ariane hiding behind him. The guards run right past them.
- Non-Human Sidekick: Arc has one after healing an injury it had; said critter turns out to be a rare spirit animal and Ponta follows him ever since.
- Rewarded as a Traitor Deserves: In the light novel, during the ambush that takes place at the beginning of the story, the bandit leader kills the guard that betrayed Lauren.
- R-Rated Opening: The anime's first episode opens with Lauren and her maid Rita being violently assaulted by some bandits, who very clearly intend to rape them, with the entire situation being played for horror. Then Arc drops in and saves the day. Though the rest of the story is mostly a comedic romp with dramatic elements, the opening does make it clear that the series does not shy away from darker subject matter, as shown in the vivid portrayals of abuse and cruelty (especially against children) later in the story.
- Shout-Out: In episode 12 as the Hydra and Ifrit face off, they briefly recreate the initial confrontation between King Ghidorah and Godzilla in Godzilla: King of the Monsters.
- Surprisingly Realistic Outcome: Using Earth Magic causes the user to manipulate the earth around them. So it's a very bad idea to use Earth Magic in a cave. Since both Arc and Goemon have Earth Magic/Ninjitsu Power, their attacks build on and amplify each other. Their final strike at the Etzat Slave Market literally destroys it and kills the enemies opposing them.
- We Help the Helpless: What Arc, Ariane and Chiyome do with their allies. They save kidnapped elves and beastmen, they protect people in danger (and in Yuriana's case, bring them back from the dead), and in different story arcs take out the chapter's Big Bad and at least once show We Do the Impossible (using Ifrit to fight and kill a Hydra that could destroy a town, and Executioner Michael to kill most of an army of 100,000 undead).