Russian pyramid is popularly known as pyramid or Russian billiards or Russian Pool. Though name is quite same but the rules of the game differ from the conventional western game of billiards.
There are different variations of Russian pyramid played. However, the most common of them are Free Pyramid or American Pyramid, Combined Pyramid or Moscow Pyramid and Dynamic or Petersburg Pyramid. All three games are played with white balls which are racked on the table in the shape of pyramid. The opening player hits this pyramid with the cue ball.
Thumb rule for all three games is that all eight balls must be pocketed in order to win the game. But in case of American pyramid, the players can use any ball as the cue one. However, in Moscow and Petersburg pyramid only one ball can be used as cue. After scoring when the player pockets the ball, he or she must remove one white ball from the table. In Moscow Pyramid, the cue ball is placed in baulk and player needs to pocket the balls only in far corner and side. And in Petersburg pyramid, the cue ball can be placed at any part of pool table by the player, but cue ball may not be pocketed.