Game Bonus (GB) is the currency used to play at cash tables and distributed during promotions. If the account holds real money, the game-bonus will be used first. At the end of a gaming session (leaving the table), the player receives back the amount of game bonuses used to buy chips at that table, and the sum of winnings is deposited in the form of real money.
For example:
A player received a game bonus of 500 rubles, joined a cash table and played one hand, betting 100 rubles and winning a pot of 200 rubles. His account will be refilled with 200 rubles of real funds, and the number of remaining game-bonuses will be 400 rubles.