I'm not 100% sure that this is a bug, but I have no idea what's causing it: my attacks emit a 3x3 field of fire, and often creates a large persistent field of purple tentacles, which I teleport out of automatically. (Skills are axes, duel-wielding, beserker rage, archaeology, assassination, smithing and perception. Pretty much every bit of my equipment has been unequipped to no effect.)
Err, my mistake. I missed a bit of encrusted equipment. Is this just a result of having encrusted equipment then?
Currently yes. It's bugged with 100% proc chance, it should be MUCH lower. It will be fixed soon. If you want to play a fixed game meanwhile use http://patches.gaslampgames.com/dredmor/dredmor_hotfix_test3.zip If you do though, no achievements tracking or save syncing.