As a long time D&D player, I've seen many times where the DM refuses to allow players to field Psionics, for various reasons, namely due to the fact that being able to manipulate outcomes and landscapes in story-breaking ways tends to be very dissuasive. While seeing the standard people chucking, mindf**king, rule breaking powers would naturally be fun, I would dearly like to RP a Psionic who mindf**ked himself, whether to block out a painful experience or to hide a secret. The type of questions you can ask; WHY did I do it, or worse, DID I really mindf**k myself, or did someone else do it to me, or was I mindf**ked at all? I would assume this will lead to a lot of performance issues in the future for this character ;D
