Back in college, I played four-hand Sheepshead quite a bit. It's a fairly simple trick-taking Skat variant, but it held our interest for years. (http://en.wikipedia.org/wiki/Sheepshead)
Why? Perhaps there are other games like this, but I haven't run across one with this mechanism. In Sheephead, there are two "partner cards"; you are partner with whoever else has the other partner card that hand (and obviously, if you dont have one, you're partner with the other player without.) Sometimes you have to play against the other three, if you are dealt both--and here the key is to bluff and try to make others think you're their partner.
The only way to know who has the partner cards is when they are played in the regular course of the game.
Now, this seems to me to have a lot of potential as a mechanism. When one partner card is played, there is an interesting information assymetry, which allows for bluffing and neat little tricks. Everyone else knows if they are the partner-card-player's partner or not, but they don't.
I have been thinking a lot recently about game designs that feature assymetric information but (roughly) symmetric structure, and this seemed a good starting place.
So, anyone want to help me think through the skeleton of a game where partnerships are determined not by negotiation but through a slowly-revealed game mechanism?
Hmm, have you perused the many (many many) Werewolf variants out there?
Will it be more of a cooperative storytelling game, or a deduction game?