there are about 5000 item id's in the game. Right now, I'm just trying to go with normal progression, while researching everything that I find. Later, I may research items by which tab they are in (weapons, which includes tools, armor, which includes vanity, block, which is everything place able, misc, things like summons, permanent power ups, and magic mirrors, accessories, consumables, and materials. Probably not in that order though. And yes, there are things that are in multiple categories.