In Brand New Day, Priestess sitting out on Goblin Slayer's expeditions during the time of the month makes sense: her bleeding and scent changes would make it easier for goblins to detect her presence.
If the tales told by Goblin Slayer's sister regarding the titular creatures originating from the green moon are indeed true, it adds a level of certainty that Truth and Illusion are really Tabletop Role PlayingGame Masters: green moon...GM.
Before tackling the goblin horde in the underground dungeon, Priestess explicitly tells Goblin Slayer she has two spells left to use. In conjunction with Dwarf Shaman's "Stupor", she uses "Silence" against the horde, and "Protection" against the ogre's "Fireball" when the latter is fought. However, she winds up stacking a third spell, a second Protection, on top of the pre-existing one when the barrier starts breaking apart. This is not a Continuity error for the Anime and Manga: per the Light Novels, there exists a phenomenon called "overcasting", where spell-casters can cast extra spells with stronger effects by going over their daily limit, but at the risk of killing themselves by doing it. A case of Shown Their Work, which is exemplified when Priestess collapses after the Fireball dissipates: she wasn't exhausted from spell-casting or from the stress of taking the ogre's attack - she was on the verge of death.
Priestess' "Revelation" ability in later volumes of the Light Novels seem to come out of nowhere, yet it may have been hinted at from Volume 1 during her first expedition: right before the goblin ambush, Priestess heard a noise (the goblins coming up from her and Wizard's rear) that Wizard did not hear at all. Since only Priestess was susceptible to this, that "noise" was really Revelation attempting to warn her about an impending attack.
The fact it didn't work too well was likely a result of Illusion's terrible luck with dice rolls. Revelation becoming increasingly effective in subsequent volumes is in accordance to Priestess losing Illusion's favor, including the latter's terrible dice rolls.
It also could be explained by the nature of the Greenhorn Team: Warrior and Wizard kept dismissing her genuine concerns about going into the goblin den without proper preparations, with Wizard in particular taking Priestess' warning about the noise before the ambush as a sign of cowardice rather than caution. This confidence boost likely did not help with making Revelation work better with Illusion's terrible luck, since a warning only works if people actually listen.
Another factor is the obvious passage of time between her first adventure and later quests where Revelation becomes more prominent: usually in Dungeons & Dragons, an ability like Revelation works by adding a modifier, which is based on one of The Six Stats. Since Priestess has successfully completed many quests with Goblin Slayer (and a Rank Up in the Adventurers Guild), she must have earned enough Experience Points to Level Up, thereby gaining stat points to boost said modifier, thus making Revelation's utility more pronounced than ever before.
The goblin paladin is able to instill courage and discipline into its horde of goblins while uniting them as a people rather than a collection of raiders, thugs, and scavengers that goblin hordes tend to be. One of the goblins even sacrifices itself for the paladin, absolutely shocking since a defining character trait of goblins is how selfish and self-centered they are with an It's All About Me mind-set. However, any tabletop player of Dungeons & Dragons or Pathfinder will state this makes perfect sense as paladins are immune to fear and its effects, with abilities that let them inspire and unite others, and can create a Battle Aura of courage that also suffuses their allies with valor and inner strength. Another subtle use of Shown Their Work where fantasy-based Character Classes are taken word-for-word from Tabletop Games and applied to this setting.
In another instance of Shown Their Work, after Goblin Slayer takes the brunt of the goblin champion's attack and lies seemingly dead in Episode 7 of the Animated Adaptation, a dice roll is seen with one die having its side of one visually lit up. In Dungeons & Dragons, if a Player Character reaches exactly zero Hit Points, a "death saving throw" is triggered, where its user must roll the dice successfully three times to get back up, else they suffer Final Death - rolling a one is considered a "critical failure". Although the dice used is the traditional six-sided die rather than a d20, even if the dice roll landed on one or merely an emphasis is placed upon it, recall the series' Tag Line: "he does not let anyone roll the dice". Goblin Slayer getting right back up regardless of the results from a death saving throw is because the character outright ignores the rules.
It seems odd Goblin Slayer chooses to repair his equipment rather than buy new ones, especially when he has the money for it through all the quests he's completed. Blacksmith explicitly points out Goblin Slayer uses cheap equipment so goblins won't be able to pillage good items from him in the event they wind up killing him, but this is further justified in Year One upon purchasing his first set after registering for the Adventurers Guild: several of his equipment, like his signature helmet, was bought using his deceased sister's life savings from her purse, which explains one of the reasons why Goblin Slayer is attached to his equipment - he doesn't want to replace it as a reminder of where it came from. Simultaneously, this also serves as a psychological sign of his stunted emotional issues and his unwillingness to let go of the past.
This could also explain why Goblin Slayer doesn't push convincing Priestess into buying another set of chainmail after the first encounter with the Water Town goblin champion, but rather suggests she has the broken one repaired, aside from the Water Town weaponsmith pointing out the impracticality of it: the chainmail means something special to Priestess, especially when Goblin Slayer praised her for wising up by purchasing it after her first quest. Indeed, by Volume 8, Priestess is dismayed when Princess steals her chainmail in an attempt at becoming an adventurer.
Year One reveals Goblin Slayer's Character Class, as registered in his guild sheet, is a hybrid of Fighter and Ranger, with some Scout, thus making Goblin Slayer a confirmed multi-class. This serves to highlight his Crippling Overspecialization of being a goblin exterminator, as many players of Dungeons & Dragons tend to focus on one class because taking on multiple often renders a character suffering from being a Master of None, like how Goblin Slayer struggles (initially) with foes who aren't specifically goblins (like the ogre in Volume 1 and the giant eye in Volume 2, for instance).
Goblin Slayer is shown to be one of the most financially stable adventurers, despite goblin slaying being a low-paying affair. Contrast others adventurers like the Ragged Party in Volume 1 and the Rookie Duo, the latter who went through a Broke Episode in Volume 4. That Goblin Slayer has amassed enough money to buy a Gate Scroll, which is stated to cost a king's ransom, and buy drinks for most of the Adventurers Guild at the end of Volume 1, is a testament to how much he has earned in five years since he started his crusade. Obviously, a major factor of Goblin Slayer's wealth is the frequency of the goblin-related quests he goes on. However, there are plenty of other signs to his lifestyle that contributes to his uptake.
As previously mentioned, Goblin Slayer only purchases cheap equipment (with the exception of something expensive like a Gate Scroll) and regularly steals spare weaponry from goblins he kills, the latter ensuring he always has weapons on hand without the need to buy new ones. Additionally, he often repairs most of his old equipment rather than take it to Blacksmith to do it for him.
Unlike most adventurers, Goblin Slayer doesn't ever go out drinking; in fact, he almost never eats at the Guild Tavern, a Plot PointDiscussed in Chapter 3 of Brand New Day where Padfoot Waitress notices he started coming into the Tavern, but only to accompany his party, thus she spends the chapter trying to get him to sit down and have a meal. While one can argue it's because he has No Social Skills, thus sees no reason to stay at the Tavern to get sustenance, it's implied he mostly only eats Cow Girl's cooking at her uncle's farm when he returns to town.
Finally, tying into the point below, the fact that most people go out of their way to avoid Goblin related quests means that there's always an abundance of them at hand. This means that Goblin Slayer has no real competition bar the occasional successful rookie group for said quests, meaning that he only really needs to keep on doing a large number of them to keep himself financially above board. While they may be low paying affairs, the sheer volume of Goblin quests combined with his preference for cheap equipment and lack of eating out at pricy taverns, even small amounts of money can build up overtime.
It's mentioned many times that higher ranked adventurers avoid goblin slaying missions like the plague. The usual explanation is most adventurers are Only in It for the Money, and goblin-related quests are high-risk low-reward pursuits. However, there's another reason alluded to in the Light Novels: higher ranked adventurers have been traumatized post-goblin slaying. Sure, goblins might be the weakest monsters around, but they are some of nastiest. Such adventurers would naturally want to avoid reliving those experiences, unless they are given decent compensation, like the climatic event from Volume 1. Further evidence to support this includes the following.
The light novels mention many higher ranked adventurers' first quests were goblin slaying ones. It's implied these quests were Not So Different than the one Priestess had to go through.
High Elf Archer, an experienced Silver-ranked adventurer, broke down crying the first time she saw a goblin's captive in Volume 1, who happened to be a fellow elf. This is a clear indication that difficult quests don't necessarily feature the same amount of cruelty seen in a goblin-based mission, a relatively "easier" quest. Furthermore, saving a Damsel in Distress loses its appeal if the latter winds up being physically maimed and psychologically broken afterwards.
An interlude chapter in Volume 1 has Heavy Warrior recount a goblin slaying mission he went on that nearly ended in disaster: one of his party members dropped their only source of light, thus the party was forced to frantically fight in pitch black darkness. Heavy Warrior discusses that were he to fight goblins a hundred times, he would certainly be killed during one of those scuffles. If he were to die, he would rather die fighting a dragon because goblins will undoubtedly give him an Undignified Death.
All this essentially loops back to the Guild's initial treatment of Goblin Slayer: for a man who continuously and willingly subjects himself to the horrors of what goblins can do on a regular basis, there must be something psychologically wrong with him, thus the adventurers paint him as an outcast.
One of Goblin Slayer's first quests was saving Chosen Heroine's village from a goblin attack. His intervention could or probably is the reason why the gods started paying attention to him. As noted in Fridge Horror below, it's possible Chosen Heroine was supposed to have a Doomed Hometown back-story; then, in the eyes of the gods, what was meant to be a generic Non-Player Character stepped onto their game board and stopped the completion of Chosen Heroine's intended origins by saving her village single-handedly through the use of awareness, Determinator and strict planning. Once again, Goblin Slayer was not letting anyone roll the dice.
After Goblin Slayer takes off his helmet in front of the Adventurers' Guild at the end of Volume 1, it's revealed there's a betting pool made on his identity. An unidentified male adventurer lost his bet because he guessed Goblin Slayer was a woman. On one hand, that's nonsensical - while his armor may disguise and fit a human woman just as well as a man, Goblin Slayer's voice is explicitly that of a male's. On the other hand, that's not an unreasonable assumption to make: in the anime and manga, there are days when Goblin Slayer comes to the Guild as soon as new quests are posted, sits down at an unoccupied table, and doesn't say a word until the majority of the morning crowd has taken the high-paying quests and left. There are probably loads of adventurers in that Guild who have never heard Goblin Slayer speak and only know of him by gossip and/or reputation. In addition, his single-minded obsession with slaughtering goblins could just as easily be attributed to that of a woman - one violated by goblins, rescued and seeking vengeance against them, especially when Noble Fencer in Volume 5 has similar motivations.
Female Knight was aspiring to be a paladin and could use miracles during Year One; in the present, she can no longer use the latter due to disfavor from her patron deity, the Supreme God (whether this is permanent or not is unknown). It's also implied this loss of favor is due to her Nun Too Holy personality with the way she values money, likes to party, and her prioritizing appearance and reputation. Ironically, the Supreme God (also known as the God of Law/Justice) does not encourage his followers to strictly adhere to his rules, but rather have it as a way of life. Female Knight's obvious character flaws, while negative, shouldn't be enough for the Supreme God to abandon her. However, there is more subtle evidence as to why she is in disfavor: if one focuses on the nature and purpose of The Paladin archetype, it's clear Female Knight isn't cut out to be one as she is now. Regardless of personality, paladins are straight-forward heroes meant for the cause of good and righteousness - doubly so if their patron deity specifically represent aspects such as justice. When Goblin Slayer petitioned the Adventurers Guild for help at the end of Volume 1, most of the adventurers, including Female Knight, are uneasy on the prospect because of its dangers and low pay. If Female Knight is aspiring to be a paladin, she should have been the first person to step up and lend her aid without question. It's one thing to choose between different quests, even with a mercenary mindset, but it's something else when Female Knight ignores a cry for help against imminent peril, particularly one happening so close to the Guild. It may not have been this event that caused her to be on the bad side of the Supreme God, but her lackadaisical attitude certainly made the deity think twice about putting her in his favor.
In Volume 3, Female Knight mentions to Goblin Slayer it's very common for drama to occur among party members of mixed genders - more often than not, these groups tend to break up because of interpersonal relations, which may lead to events such as Cavalry Refusal and In the Back. Romantic attraction among party members is seen with the many named characters of Goblin Slayer, ranging from Priestess and High Elf Archer to the titular protagonist, Female Knight for Heavy Warrior, Witch with Spearman, Newbie Swordsman to Half-Elf Shaman, etc. If it's true most parties fizzle out because of In-UniverseRelationship Values, it certainly explains why several of those aforementioned characters Cannot Spit It Out: they are consciously worried about ruining their respective party's dynamic.
Considering how essential Goblin Slayers ambush tactics are, it raises some tough questions about how better equipped fighters got to actually be better equipped. Sure higher level quests provide higher rewards, but the number of team wipes against more capable opponents must be massive. How many of these surviving heroes actually made it to where they are through just being skilled fighters, rather than stepping on the backs of past team members?
As much as the Goblins were indeed assholes for what they've done, especially to the village where GS himself lives in, their actions (on GS's village in this case) was an accidental act of the birth of the Bane of Goblins/Goblin Slayer. Think about it; what would happen if the goblins never attacked as GS grew up? He may never be the Goblin-Killing Anti-hero we all know and love. Given that he wanted to be an adventurer before the raid took place, he would very likely be just one of those adventurers who ignorantly knows nothing about the true dangers of Goblins. Worse, he wouldn't be largely free from the whims of Gods.
Worse still, who was going to save the villagers, ensure that the goblins don't reproduce, or save Priestess on that fateful day? Who will the other races' representative have to find? As awful as it is, we have the goblins to thank for giving the villagers a new (anti-)hero.
With the debut of the Goblin Champions and Goblin Lord, they tell a very dark tale of what happens when adventurers show mercy to such Goblins, to say nothing of the unfortunate ends of such adventurers.
One of GS's first jobs resulted in him saving Chosen Heroine's hometown from a band of goblins. Now, taking into account the fact that GS defy Fate at every turn, this means that GS may very well have prevented Truth from subjecting Chosen Heroine to a Doomed Hometown backstory. Now take into account of what would happen if the first Fridge Horror entry happened......those who realize that Chosen Heroine seems to resemble Konno Yuuki would not like the idea of Yuuki facing a fate worse than death...
Assume that Chosen Heroine was fated to suffer a Doomed Hometown backstory, it would certainly make sense that the her hometown was attacked on the same day as the Rock Eater incident. Almost every adventurer available took the Rock Eater quest, leaving only Goblin Slayer left to take the job to defend Chosen Heroine's hometown.
Sooner or later, the horrifying issue of what would happen to a girl who is rescued, alive but pregnant with goblin-child, will have to be dealt with. That awful moment when Goblin Slayer brings the mace down on her belly, or worse, on the little monsters head as soon as she pushes him out of her body into this world, is all but inevitable.
For the same reason that adventurers female AND male in this world (minus Goblin Slayer) tend to instinctively spare the lives of Goblin children (and get a hammer in the back of their heads for their troubles); the world of Goblin Slayer is NOT the world of George RR Martin, and hence it is still normal human-instinct to feel compassion towards ANY helpless young child, even those NOT of your blood. Even our sweet little heroine priestess was willing to beg for mercy towards the little beasts in the very first chapter. And note the prefix of a possibility, however slight; this is fiction, and ANY scenario, even the most ludicrous can happen. Heck, children of violence who are NOT tied to a stone and thrown into a river by their mothers do exist in Real Life too; some are even raised to adulthood by their birth-mothers, loved and treasured as if they were not conceived in violence and hate. Stranger than fiction? Indeed it is but hey, it still happens.
Do we know for sure that EVERY result of a goblin mating is a goblin? What if goblin genes are just carried on the Y chromosome, for example? We haven't seen any non-goblin results, but we do already know that the goblins eat non-goblins...
Goblin "mating" is more a matter of implanting a parasite that grows in a womb. Women do not ovulate often enough for "mating" to happen every few days. The genetic material the goblins implant via rape grows in the space meant for human gestation, but is 100% not human (100% goblin). Thinking these are the "children" of those raped women is like thinking the aliens in the Alien movies are the children of humans, just because they burst out of human chests.
The above comments miss the point: part of the reason human women feel any maternal instinct to their children is because the 9 months of pregnancy allow them to bond with their child. This explains, in part, why men are encouraged to spend a lot of time with their newborns, because they didn't have the same bonding experience and therefore don't necessarily feel as connected to their baby. Goblin pregnancies, on the other hand, are FAST. Brutally so. All of that time bonding? Gone. In fact, the sheer abnormality of the speedy pregnancy is far more likely to induce disgust and horror than maternal instinct. Adding on to that that whether or not you buy the Green Moon story, the women are either birthing a monster or an alien. Either way, they are all too aware that what they will birth is decidedly not human. Yeah, even if the majority of the women can get over the trauma of their own brutal assault, violation by numerous monsters, and forced pregnancies to care for the monsters now popping out of them, you'd be hard-pressed to find anyone capable of forming any positive bond/maternal instinct in 1-2 weeks to what amounts to a an non-human invader/occupier of their own body.
Goblin Slayer Side Story: Year One reveals that women impregnated by goblins will give birth in less than a week of gestation. This would example why there were quite a few goblin children in first episode even though it is implied the girls weren't captured for very long. Additionally, Goblin Slayer's comment about the number of goblins increasing to about fifty goblins if left alone any longer make much more sense. The "horror" part is realizing how many goblins a single captured woman might be able to produce before Death by Childbirth, due to the often occurrence and unsanitary conditions. This also make several particular scenes involving women captured by goblins more horrifying:
On Priestess's first adventure, if you look closely, you will notice there are 4 captive women (excluding the recently captured Fighter) and 4 goblin children. It's not hard to figure out what happened.
In Chapter 6 of Goblin Slayer Side Story: Year One, Goblin Slayer find a single captive woman that was held in the Goblin Nest for about a week, and three goblin children. There are no signs of any other captives. If it wasn't obvious, the light novel gives the woman the unfortunate moniker of "Goblin-Mother".
In Chapter 4 of Volume 4/Brand New Day, Goblin Slayer states if the surviving Hobgoblin escapes with the captured Spearwoman, the Hobgoblin will be able to make a new nest using just her. So the bare minimum needed to create a nest of 10-20 goblins is a single goblin and 1 captive woman. This certainly adds a new layer to Goblin Slayer's mindset.
Noble Knight, the leader of the all female rescue party in Volume 1 of the light novel and Chapter 4 of the manga, had her death play out slightly differently in light novel and manga. In the light novel, Noble Knight dies are spending 3 days and 3 nights being tortured and raped by the goblins before dying of mutilation. In the manga, it's never specified how long Noble Knight was held captive by the goblins other than Goblin Slayer saying that it has been "too long" for there to be any survivors, and she seemingly dies from exhaustion. Due to the unspecified time frame in the manga, Death by Childbirth does seem like a possibility.
In chapter 30 of the manga, it's revealed that women captured by goblins tend to only last 2 weeks at most. This makes sense given the goblins' sadistic nature and unsanitary conditions. However, it's revealed in the same chapter that goblins under the control of more pragmatically intelligent leaders, like Dark Elf, are capable of keeping them alive longer than 2 weeks. This would explain the Goblin Lord's large army during the Farm arc...
On the subject of the fates of the manga version of the female party from Chapter 4, as stated above, was slightly changed from the light novel. In the manga, we get a clear view of Noble Knight's body being raped by goblins, the same thing seem to be happening to Human Monk, while Rhea Ranger and Elf Wizard suffer the same fates as the light novel. This is the only known instance where goblins demonstrated I Love the Dead. Although goblins aren't picky about molesting wounded or dying women, as shown with Wizard. However, as Goblin Slayer pointed out in the Water Town arc, goblins would normally try to eat the women not long after they die. Noble Knight's body, who doesn't have any noticeable fatal injuries, doesn't look an worse than the other still alive captured woman shown in the series. Additionally, as shown in Chapter 30, Goblin Slayer did incorrectly guess the women captured were dead, showing he is capable of making mistakes. This can lead to some horrifying implication:
The first implication is that the entire party died very recently, as evidence by Elf Wizard's body being consumed by a still roaring fire, meaning that Goblin Slayer and Priestess just missed their chance to save the party by a few hours, or..
Noble Knight and Human Monk were kept alive as BreedingSlaves. The only real indication that they are truly dead is Goblin Slayer stating that any "would-be rescuers" should have died by now. Granted, he didn't actually see the bodies and this is a guy who prioritizes killing goblins over saving captives. So if one does believe that Noble Knight and Human Monk are still alive, then that means Goblin Slayer just burned to death two traumatized women without realizing it.
One thing that several people might have found odd is why the goblins in the first episode opted to fatally wound Wizard instead of keeping her alive for breeding. As pointed out by the Shoot the Mage First entry on the main page, magic-users tend to be killed off by goblins while melee fighters, like Fighter, Spearwoman, and possibly Noble Knight in manga version, are often kept alive to be BreedingSlaves. If one does think about it, there are a couple of possible reasons behind this:
First, stronger magic-users like Witch and Dwarf Shaman are able to cast spells without the aid of an item, like a wand, staff, or bones like the ones Lizard Priest carries around. So to the goblins, it would be too dangerous to keep someone alive that might have the capability of creating a powerful attack by just saying a few words. This is likely the reason why they fatally wounded Wizard, as they saw her cast one spell and knew she would be able to cast more.
Magic in the world of Goblin Slayer tends to be treated as a skill that can be taught, often by devoting yourself to a particular god to obtain his or her blessing, and not as something that can be passed down genetically. But something that can be passed down genetically is physical strength. Assuming goblins do inherit traits from their mothers, then the goblins' tendency to keep melee fighters alive makes more sense as they would want goblins with similar athletic capabilities as those melee fighters.
Possibly the most horrifying reason why they keep melee fighters alive is because stronger women are more likely to last than physically weaker magic-users. As mentioned in chapter 4 of the first volume of the light novels, a captured village girl was only about to "service" 10 goblins before dying. Whereas the athletic Spearwoman spends several day being passed around by 18 goblins, and was able to make a full recovery after she was saved. Naturally, the longer a Breeding Slave is able to stay alive, the more goblins they would be able to produce.
The world of Goblin Slayer seems to work on Vancian Magic so any magic user would "reload" after one night's sleep. Regardless of how helpless they appear now, they could suddenly become a major threat hours later once their spells refresh.
A noticeable reoccurring injury that many goblin captives are shown to have in the manga is bite marks on their breasts, as seen with Noble Knight and with the "meat shields". The Year One light novel even points out these injuries on the "Goblin-Mother"(a captive saved by Goblin Slayer on his first adventure). This seems to be an odd thing that keep coming up and even brought up, until one realize these bite marks were likely caused as a result of goblin children trying to breast feed from their mothers. The "horror" part is realizing that these injuries may be an indicator on which women have actually gave birth to a goblin child.