What's Resistance?
I might be /in. If not, I want to at least /tag.
It's a mafia-esque game of social deduction. A number of players will secretly be spies, trying to sabotage the resistance. Players take turns proposing missions of varying numbers of players. People vote on if they want the missions to go ahead or not. If a mission does go ahead, then people on the mission get the choice of passing the mission, and doing what they're meant to - or sabotaging the mission secretly if they're a spy. Players find out how many times a mission was sabotaged, but not by whom. A mission only needs a single sabotage played for it to fail (usually). The resistance win by passing three missions, and spies win by sabotaging three missions.
The Avalon version introduces a few new roles which have new effects - most notably, "Merlin" who knows all the spies, who is counterbalanced by the assassin - a spy who, if the resistance passes three missions, can attempt to kill Merlin, and if she succeeds, wins the games for the spies.
That's a short overview. If you check the old Resistance threads, you can probably find rules and see examples of gameplay. The most recent game was a notably confusing one, so I'd look for very early or vanilla ones to see the basic game in action.