“Priest of Flame” conduct, only available to Priests: they start with a lit candle or other source of flame, and must keep a lit flame on them at all times to maintain the conduct.

A bag of tricks occasionally spits out a candy bar instead of a monster (or perhaps along with / carried by a monster), but only on Halloween.

If you get a stack of 10 (or 5) identical scrolls that correspond to an existing spellbook, there is some ritual available which will let you convert them into the spellbook, possibly dropping them on an altar and praying.

You are only capable of regenerating health when you are standing still in one place, resting (or searching). Continuing to move around the level or fight things does not allow you to passively heal.

The enchantment on non-blessed weapons degrades by 1 point after a certain number of hits, roughly 100. Cursed weapons degrade in half the number of hits. Possibly, this auto-identifies the enchantment when it happens.

There could be some mechanism to prevent degradation by resetting the counter on a weapon, such as using a whetstone on it. (Not that this makes sense for non-slashing weapons.)

Take a page out of Brogue’s book for streamlining weapon identification: after a certain number of attacks, hits, or kills with a weapon, the weapon’s enchantment (but nothing else about it) becomes identified.

Possibly, it could take less time to identify a weapon the higher the absolute value of the enchantment. It should be pretty easy to tell that a weapon is really bad or good, compared to middling.

Behavior is undefined regarding stacking. E.g. if you drop 9 of your 10 daggers, use the other one a bunch, and come back to pick up the 9, should they still stack together? If not, it would make using stackable weapons very annoying. If you use the one dagger enough to identify it, should the others automatically become identified? Only if you try to stack them together? Not at all?

Scrolls can be “corrupted” or “misspelled”. This basically acts as a toggle on whether the confused behavior of the scroll activates: reading a corrupted scroll while not confused will produce the confused effect and reading it while confused will produce the regular effect. There is no way to restore a corrupted scroll to normal.

Possibly, an unidentified corrupted scroll will have its label deterministically garbled similar to engravings, e.g. “scroll labeled FO0B|E BLe7Ch”. If identified it would simply show as “corrupted scroll of X”.

Writing a scroll while confused will make the result corrupted. Also, scrolls hit by water damage or produced from polymorphing other scrolls may be corrupted.

Water nymphs may create a pool on their spot when killed. Items they stole from the player fall into it, of course.

Wood nymphs may create a tree on their spot when killed, and mountain nymphs may leave a boulder.