Throwing Bones

Gambling games are an excellent way to turn this . . . . 

"Bones" is a popular dice game originally played by  Varisian travellers, but now popular in gambling dens and inns throughout Golarion.  There are myriad local variants, and each Keeper has his or her own style.  The generally agreed upon rules are detailed below:

The Game

The game is run by the house or a "Keeper" who throws the Skull.  This is a single die carved of dense bone, usually with twenty sides (thorugh some skulls have twelve, ten or eight sides).  The players each purchase "bones" --- dice with the same number of sides as the Skull ---- for the cost of the buy-in (usually a copper or silver piece).  All players roll their dice at the same time.  Each Bone that rolls higher than the Skull pays out double, with ties going to the house.   Bones that roll below the Skull are losses or lost souls.

Variations

Trips
The Keeper will sometimes call a "trip," a number that pays out triple (or more) if it is rolled on a bone.  Generally, if the skull roles a trip, it is a blanket win for the house.

Down the Steps
Players can choose to go "down the steps," choosing to throw a die smaller than the skull (such as a twelve sided bone against a 20 sided skull).  Each step down increases the payout by a factor of one (while reducing the odds of winning).

The Chasm and the Keep
These often used rules mean that bones that roll a 20 (the Keep) pay out triple, while any bone that comes up a 1 (the Chasm) makes all other bones rolled by the player into lost souls.  These rules are not usually combined with playing down the steps.

 . . . into this.  AS if my players needed help starting fights.

Gm Note:
We played a variant of this game one night when most of my players had gone home, and it was pretty fun.  The odds are pretty close to even, depending on rules variants, so nobody lost or made too much money over the course of several games.  I'm thinking that this will come up again, with the newly codified rules.