Ouch.One session with a grumpy DM:
"Where's your character sheet?"
"Err... I forgot it."
"Okay... your character is dead. Make up a new one!"

Excellent Nightmare Fuel. Did that unhinge anyone else?i end on the one who yelled the warning and say, "no, it's all ok." then i mime raising the gun to my temple and pulling the trigger.
end result, horror the players could bite off and chew when they realize that their pcs were also potentially a threat to themselves. the gm and i were very proud, i think, of the impact of that moment. i still miss that character.
Excellent Nightmare Fuel. Did that unhinge anyone else?
nope.
they were all, mostly, much more sane than i was at that point. one pc had a habit of steping out of the room right before something sanity shattering happened. one started out with more sanity than any other two party members combined. one was already insane and had become emotionally detatched from reality, and so didn't suffer from sanity loss for seeing it. the last one had told the dm before the game that if my character caused any more trouble for the party that he might have to have an accident, and so was unmoved.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.