I am not allowed to build characters in BESM (Big Eyes, Small Mouth) with immunities based on D&D attack forms/special attacks and conditions. (e.g. abilities like evasion+mettle and immunity to ability damage/drain, petrification, poison, transmutation, blindness, deafness, surprise, etc.)
edit: The important thing to keep in mind here is that BESM is a point-creation system, kind of like GURPS as I understand it, but it's a lot looser and easier to 'sploit. When our GM awarded us 200 something points to build characters, I spent OVER ONE HUNDRED FIFTY POINTS ON IMMUNITIES, and created a couple simple, versatile attacks with the remaining fifty points. The attacks I created were bad enough to warrant me getting "banned for life" from his games, but the immunities were "too over-the-top" for him. I calmly explained to him that he'd given us enough points to create a god, and so I did. He was not amused. (I can't help it if the other players in the group can't optimize their way out of a paper bag.)
200 points? Isn't that equivalent to a level 40 D&D character?
See, that's the point I was trying to make to him. Apparently it was "fairly average" for the other players, who didn't seem to have a very good grasp on the game at all, and blew a lot of their character points on ridiculous things like teleportation, reincarnation/regeneration, incorporeality, transmutation, flight, and bizarre and unnecessary transformation sequences. I just gave my character an extraordinarily high initiative, a ranged attack pattern, super speed & super strength, heavy armor, deception/feinting, the equivalent of a 'works-on-anything' Sneak Attack (constructs, undead, incorporeal, immortals, etc.) ability, and immunity to everything under the sun (and places the sun doesn't shine).
I could kill virtually any of the other characters in a straight fight (and was guaranteed to kill them in an unfair one). The GM got mad for my having "broken" the game. *sigh* Just goes to show you how years of my robust roleplaying experience ruined the game for others (namely the GM) who didn't understand their own system of choice. He was expecting me to spend my points on things like skills ... which are utterly useless if you have even a modicum of imagination and roleplaying skill (except the combat skills, of course, which I'd maxed out quite inexpensively).