I think what people forget about Mary Sues is how easily they can be defeated. For example: *Barbados slashes at his torso while he is exposed from his overhead strike* *Mary Sue does a backflip, landing on Barbados's face , and plunging his knife into him 50 times with his super speed.* ((I call bullshit, dude. I'm not accepting that.)) Alt 1: ((Okay, I guess you got me...)) ((Cool! Let's continue, then.)) Alt 2: ((No! Mary Sue's a superhero! You can't kill him! Go fuck yourself!)) ((Then this fight never happened. I'm not RPing with you until you nerf your character.)) I've seen alt 1 happen a lot more than alt 2. Just calmly remind them to keep their characters mortal, and if that doesn't work, then don't RP with them. Simple. Be sure to tell the character(s) involved in your RPs what your plan is! If you tell them beforehand that you aren't comfortable with your character dying, then people aren't going to put you in situations where you have to godmod or Mary Sue to get out of it. Just a good tip