Murder Mystery Night
Murder Mystery Night is a text-based roleplaying adventure using (loosely) the World of Darkness game system, by White Wolf.
Before the game begins, you choose a character from a list of premade characters. You are given a character sheet which has been made for you, and it contains instructions and prompts to guide you in how best to roleplay the character you chose.
You then sit down to dinner with all of the other players, and a few Storyteller NPCs.
Everything goes fine for a while. Then people start dying. Other players will die. The main goal is to make those people not be you.
Simple, right? Well, some of the characters have special objectives. And, of course, one of the players is a ruthless, cold-blooded murderer who will stop at nothing to make sure each and every one of you lies dead before sunrise.