James McMurray said:You can, but why would you want to?
pawsplay said:In case you need to cast a spell defensively while being attacked by a grappling creature with poison (Con damage)?
Zathraas said:or even just being distracted by a hot elven babe that walked into the room during casting.
Bagpuss said:Except it's a +4 rather than +3, and applies the majority of the time, you need to make concentration checks.