I love games. And I'm not all that picky--we've got board games and card games and computer games and Wii games...you get the idea. But one of my favorite games, probably because I'm twisted, is the game of Werewolves.
Werewolves comes from a game called Mafia, which was made up by a psychology grad student in 1986. The premise is fairly simple: you get a group of eight people or more, pass out roles that the players aren't allowed to share, and start playing based off of whatever character you get. In the most basic game, you're either a werewolf or a villager--if you're a werewolf, you want to eat villagers until you rule the town, and if you're a villager, you want to execute all those vicious werewolves so you'll stop getting eaten.
Okay, so it sounds more complicated on paper than it does in my head. Just trust me. It's fun. I play it every year with my class (I moderated it today, in fact!), and my students rush out and buy copies over the weekend to play with their friends. And it really does help with writing! Watching for people's tells while lying, and figuring out how to manipulate others when you're a werewolf--it's a play of charisma, rhetoric, and character study that I love. In case I've confused you more than helped, there's a video below that explains the basics (although the included games are not nearly as good as the games I've played/moderated). But werewolves is awesome! You should try to play it, and tell me if you do!