Indoor games and sports is captured and removed from the board. The object of the game is to trap (checkmate) the enemy king by putting it in a position where it cannot escape capture. Various indoor games, including billiards, snooker and pool, are played on a large, flat, cloth-covered table with six pockets. In these games, each of the two players tries to pot the balls (knock them into the pockets) by striking them with a cue-ball, which is hit with the tip of a stick called a cue. In "billiards", there are just three balls: a white cue-ball for each player and one
Billiard table leather or plastic, may have drop pockets, which are small nets, bags or cups to catch the balls. Ball returns, instead have a series of troughs or gutters inside the table, which channel the balls into a collection chamber on one side of the table. On a coin-operated table, the balls are deposited inside an inaccessible compartment window until the table is paid again, allowing the balls to be released into the collection chamber. A disadvantage to drop pockets is that if too many balls go into the same pocket, it will fill up the receptacle and prevent any more