G. 31. Vampire

To start, everyone closes their eyes (vampires roam only at night) and begins to mill around. The leader should keep participants from colliding with anything but warm, living flesh and explain that if they get caught by the vampire they will be transformed into one, too.

However, participants can’t trust the leader to protect them from the consequences: the leader will surreptitiously notify one of them that he/she is the vampire and explain how to play this role.

Like everyone else, the vampire keeps his/her eyes closed, but when s/he bumps into someone else, there’s a difference. S/he snatches the person and lets out a bloodcurdling scream. He or she, no doubt, does the same… (The vampire would be advised to avoid leaving telltale marks on the necks of her victims.)
The quality of the vampire's performance depends solely on the authenticity with which s/he executes his/her "snatch and scream".

Any victim of the vampire, becomes a vampire, too. Once the victim has regained composure, he or she goes back on the prowl, seeking new victims.

However, the game will not quickly degenerate into an all-monster convention - for when two vampires "feast" on each other, they are transformed back into ordinary mortals. The question is whether the vampires end up neutralizing each other before all mortals are tainted by the bloodsucking scourge!!

Why not try a little experiment and see? There’s always hope even in the midst of a bloodcurdling crowd.