Oh, of course. They just have to avoid getting shot and dying horribly. Plus all the psychological scars from any non-fatal wounds.

John is tempted, briefly, to point out psychological scars don't only come from getting injured yourself -- but that's too close to home. That's more truth than is necessary for a game. Instead, he gives McKay a sideways glance and scrunches his face in a way that clearly suggests he thinks something is wrong with him.

"Go on, get it out of your system" he drawls, letting McKay pinch at his hand. He has a momentary weird, vivid vision of how much damage they could do to each other without it hurting before he stamps it down and shoves the thought back in a cupboard.