Which of the following, in your collective opinions, are good features for an identification subgame? I'm trying to make something that's interesting and has moderate depth, but not punishing nor too grindy.
I plan having no "identify" effect as such in the game at all, replacing it with means of fairly quickly learning which things are (reasonably) safe to try out and experiment with, combined with various channels that can give more specific information if you bother to use them but usually won't provide full certain identification.
Looking through rings. If you have a ring whose magic is of a general type, then when looking through it, you can "see the aura of a similar enchantment" and tell whether another item has the same general type of magic. For example, looking through your levitation ring should give you a positive reading for the flying broom and looking through your stealth ring should give you positive readings on the shadow cloak and the silent boots. This effect can be used to link ring enchantments with other item enchantments in general families, giving partial-identify information both for rings (where other items are known) and for items (where rings are known).
Rarities Rarities are item types or varieties that only exist in a fraction of all games, making the number of "unidentified categories" uncertain. For example, in a game with a dozen standard types of rings, one game might have fifteen ring types (because three rarities were included) and a different game might have eighteen ring types (because six rarities were included). The point is that the player does not start the game knowing how many kinds of rings there are, nor knowing exactly what kinds of rings (beyond the basic dozen) are there, so certain kinds of "process of elimination" subgames for item ident become more interesting.
Combos One kind of rarity is the combo, an item which has essentially both the effects of two randomly-selected "standard" items. And when the combo is included, both the standard types are eliminated. For example, a rarity boot type combining stealth and feather-fall may be a "combo" in a given game, and standard stealthy boots and featherfalling boots would not appear in games where that combo item appeared. So instead of a dozen standard types of boots there are only 10 standard types plus the combo and any other rarities. The point is that in the presence of combos, the player doesn't start the game knowing for sure even which standard types of boots exist in that game. Selecting effects to combine should be weighted against the most powerful effects, to avoid creating combos of unbalanced power too frequently.
Detect effects A number of detects can give information about items without giving full identify information. For example a relatively easy "detect magic" effect (a "magic ring" with no particular effect, if you're allowing look through rings) can be used to tell which items are magical. A "detect curse" effect can be used to tell which items are cursed. Other "detect" spells might reveal which things use elemental magic, which use fire magic, and so on.
ID by Use. When a character puts on both an unidentified ring and some unidentified boots, and then later sets off a pit trap but floats gently to the bottom instead of falling, should the character automatically know which of the unidentified items caused floating rather than falling? When a combat-knowledgeable character like a fighter picks up an unidentified sword and uses it through a few fights, he should know very quickly what general combat bonuses it has been giving him. But should he notice the 'dragon-slaying' magic on it if none of the things he fought with it were dragons? A less combat-knowledgeable character like a wizard, picking up an unidentified blade and using it for a while, might take a lot longer to figure out what combat bonuses it's been giving, but would eventually figure it out because he'll notice the magic working. So should the wizard, who is a more magic-sensitive character, notice the dragon-slaying magic lying latent in the blade after fighting a bunch of non-dragons with it?
Item Variability Items of the same type may differ significantly in their effect; We're already used to seeing swords that vary in hit and damage bonuses. What if wands also varied in their range, area of effect, number of charges possible, and damage? What if some have a cooldown period and others don't? What if occasionally a wand has a weird inexplicable trait like having doubled range when fired northward and half range when fired southward, or the last charge always comes out at double strength?
Labels. Some item types might be clearly and correctly labeled. Common things like healing potions that we can imagine being used for trade, especially. This could provide a major advantage to characters with the literacy skill. Of course some labels might be cryptic or miss important information. The clearly labeled "fireball wand" might neglect to mention that it has five charges and creates a fireball sixty meters wide, within which volume the user will almost certainly be if he is so misfortunate as to use it indoors. If I introduce mislabeling (the poison that's labeled as healing potion) I should probably introduce an effect to magically detect mislabeled items. But if the player creates a label for something, it should call it mislabeling unless the character actually knew what it was *and* labeled it correctly.