These aren't technically bugs, but are nonetheless small issues of clarity that it would be of benefit to new players to reword. Listed are the few that come to my mind at the moment - please help to compile this list by adding any other descriptions or messages that confused you upon first reading.
* The codex descriptions for several gods state that they will "punish you" for performing an action they dislike. As mere piety loss is distinctly different from the god's actual listed punishment, these should be reworded. On a related note, the fact that Taurog will immediately punish you without piety loss for converting one of his gifts is recorded nowhere despite being fairly important.
* The player status 'life steal' is ambiguous as to whether the health restored is determined by your character's level or the enemy's level.
* The enemy status 'beserks' claims that damage will be +100%, but this is either wildly inaccurate or needs the player to be able to view the enemy's base and bonus damage to make sense of. For example, a level 2 berserker in the Berserker Camp will only go from 7 to 10 total damage, not 7 to 14.
* LEMMISI is described as seeking nearby enemies. Through many uses I have yet to see any indication that the distance of the tile revealed is anything but random, and it appears to favour dungeon features and items over enemies. So.
* Mentioned before, but several quests that require the character to win with a badge do not give the player a complete description of what is required. For example, the witch at one point tells you not to drink any potions when AFAIR drinking non health/mana potions was still allowed as per the Feeling Parched badge.
* The description for Halls of Steel states that beating it with four classes will unlock vicious mode. This is vague; several other vicious dungeons and the vicious token itself can be unlocked first elsewhere. As the quest 'Vicious Edge' provides a more specific explanation (ie. it unlocks that particular vicious variant as a new dungeon) the note on dungeon description is redundant in any case.
* That WONAFYT does not effect higher level enemies and cannot be cast at all if no applicable enemies exist is stated exactly nowhere in-game that I can recall. And although the puzzle packs did eventually help me understand the nuances of BURNDAYRAZ, the glyph description confused the heck out of me when I first started playing as it makes no reference to the existence, function or importance of burning stacks other than a vague mention of the usually less important effect of regeneration slowing.