The Doubling Cube
Backgammon is not usually a gambling game but sometimes it is used in casinos to help lure people in that normally would not go to a casino.
The way betting work is in Backgammon is relatively easy a bet is placed before the game starts. Then during the backgammon game a player may raise the bet by challenging his player to raise the point. There is a point cube also known as the doubling cube with number on it similar to a die. Before a players turn he may raise the point. His opponent then has the choice to take the raise or declare defeat. Each time the point is raised the original bet is doubled. But in tournament play there is a point max of 13 except in the championship rounds.
After a backgammon player had doubled the point the accepting player takes control of the cube. This means you can only double once then the other player has to double before you can get the cube back.
Some players use automatic doubling if the first roll is doubles, the point of the game automatically becomes 2. The cube would then remain in the center of the board until someone decides to double it again. There is also a rule called beavering This means a player has doubled the point and the opponent takes the cube but if he thinks he actually has the advantage he will turn the cube to the next number doubling the doubled point but he can still keep control of the cube and double it again latter if he so chooses.
This is how betting on backgammon works I hope it ill will help you in your game.