Sometimes it is fun to play a game wthin a game, particularly a game wthin a tabletop roleplaying game, when you can play that inner game in-character. It adds flavor to the setting and creates a different kind of tension in the experience, and tension within the game is often a good thing to promote. On more than a few occasions I have broken out a little dice game caled Ship, Captain, Crew (available for free from Creative Mountain Games!).
It's a simple game to learn and fast paced to play. If you can manage to get the players to stay in character while playing, it is not only a fun exercise but an easy way to get the players who tend to be more shy to open up and roleplay a bit more than usual. It's low stakes to roleplay while the character is only involved with the setting through a game which the character is playing. The fact that the player is going through the same motions that the character would be, rolling the dice, perhaps wagering in-game a little, and even grumbling if the dice don't come up their way, makes roleplaying a lot more natural and the lessons learned while doing so carry over to the rest of the gaming experience. Give it a try!
Ship, Captain, Crew
other dice games
Fast games of cards or backgammon