Cooking system in which you apply a knife to corpses to turn them into raw ingredients, then combine them over a hot surface such as a campfire or lava to turn them into food items that are superior to raw corpses, whether that’s by having increased nutrition, conferring temporary slow digestion, boosted intrinsic odds, raising attributes, or other benefits. One specific recipe mentioned is combining a cockatrice’s heart and potion of acid to produce a food that cures stoning and gives temporary stoning resistance.

The lack of cooking gear in the game (other than dented pots) means there might have to be some sort of fixed “cookpot” dungeon feature found at various places which acts like the ones in Zelda: Breath of the Wild; a specific place to combine food items together.

If the cooking system uses fixed recipes, there should be cookbooks containing various recipes so they don’t require spoilers to find out.

One major flaw pointed out with a cooking system is that it has to somehow establish itself as better than merely eating corpses, so it either has to deliver amazing benefits from eating the food or nerf corpse-eating, while still allowing it to be practical to play vegan or foodless. One possibility is to remove most roles’ ability to eat raw corpses (Barbarians and Cavemen could retain this ability as a role benefit).

Artifact book (novel?) that when read teaches you one level of any skill. This may include skills you are restricted in (though it might only raise it to Unskilled) and skills past your role’s cap.

A non-magical book like a novel that describes how to do the invocation.

New type of book “encyclopedia”:

• Appears as a “hardback book” when unidentified, base price 300.
• Nonmagical and always polypiles into a blank spellbook.
• When read, it adds the appearance of some unknown magical items (1d4 if blessed, 1d3 if uncursed, 1 if cursed, plus 1 if you are an Archeologist) to your discovery list.
• It doesn’t disappear when read, but will set a flag that prevents its effects from happening again. This flag will be cleared when creating a bones file.
• Archeologists start with a special blessed encyclopedia (using a different flag), which is their research (the starting one comes pre-read and isn’t useful to this character). Reading an unread archeologist encyclopedia gives the message “These seem to be an archeologist’s notes. You pore over them intently.”, and type-IDs two unknown scrolls, rings, amulets, and wands, and puts two blessed scrolls of magic mapping into your inventory.
• The Archeologist home level contains another encyclopedia.
• There has to be an incentive for archeologists carrying around their encyclopedia so it doesn’t just get discarded as dead weight. A flavorful way to do this would be to award them extra experience points (say, double or triple) when they learn new object types while carrying an encyclopedia.

Implement “spoiler novels”, cheap books like 3.6 novels that contain spoilers. (Not described in what form the spoilers would be. Several true rumors?)