Calaboose is an exciting card game for 2-5 players (ages 12+) from Live Oak Games. Players play the part of sheriffs in the Old West, each trying to capture the highest value collection of outlaws in their jails.
Your jail (aka Calaboose) is a collection of cards kept face up on the table in front of you. Jails can only hold 5 outlaws at any one time, and each outlaw has a "strength" rating.
On your turn, you can either place an outlaw from your hand into an empty slot in your jail or into someone else's jail. The outlaws each have "power" ratings. An outlaw can be sent to replace a weaker outlaw in someone else's jail.
You can defend your jail. If someone sends an outlaw to your jail, you can eliminate him with one of your outlaws - but you have to send your defender to someone else's jail. That person can defend against you, of course, so each turn has the possibility of generating a chain reaction that involves multiple players around the table.
It's a lighthearted social game with a solid core of strategy. Higher value cards tend to be weaker, and sets (or "gangs") are worth much more than singletons. Everyone at the table can see what's in your jail, so as you gain the advantage you also acquire a bullseye. Attacking another player's jail may backfire on you, so you have to be careful and constantly adjust your strategy to the cards on the table.