[evilbutterfly]

In TWG there are two teams, humans and werewolves. The game consists of day and night. During the night, the wolves decide which human to kill. During the day, people decide who they think is a wolf and vote them off. The wolves know who the other wolves are and try to trick the humans into voting each other off. The humans must try and find other humans they can trust and work together to kill the wolves. We usually play it so there are 15 people, 3 of which are wolves. There are also special roles:

Seer - every night they pick one person to look at and the moderator tells them if that person is human or wolf
Guardian - every night they pick one person to guard. If the wolves decide to try and kill that person, the kill will be unsuccessful
Psycic - every morning they are told how many wolves remain. In this way they can figure out if the humans have been correct in their voting or not
Master Wolf - this wolf can fool the seer. If the seer chooses to look at the Master Wolf, the moderator informs the seer that he is human (though he is not)
Masons - a group of humans who know each other at the beginning of the game. This helps by starting the game with an alliance

There are others, and not all special roles are used every game, it's up to the moderator. Also, note that days and nights don't relate at all to real life. For example, in TWG5 days were 60 hours long, and Night only lasts as long as it takes all wolves/guardians/night-time people to send in their targets.