When you cast atem on a group of monsters, if one of them resists the acid side effect, then the room spell damage does not hit that monster.
Please fix this.
Reported 3 years ago. Good luck.
http://www.greatermud.com/forums/index.php?topic=4002.msg18444#msg18444
http://www.greatermud.com/forums/index.php?topic=4649.msg22066#msg22066