ToME: the Tales of Maj'Eyal

5%, huh? The random number generator must be extracting its payment for letting me get this far, then.

Tannen's Tower (3) (the water spiral) generated a boulder trap in the hallway that can't be passed, effectively making the level unbeatable by anyone without points in Heightened Senses. (At least I assume it can be disarmed. I haven't bothered to try the console yet.)