Quote Originally Posted by Kurald Galain View Post
The thing is that taking equipment away permanently is seen as a poor tactic, whereas taking equipment away temporarily is fair game.
I would call it bad form to take away anything the PCs are utterly dependent upon to function as characters, even temporarily. A Wizard's spellbook is a great example of something that should be immune to this, unless you intend to return it before the next time they prepare spells.