Tambola is a variant of the game bingo. A caller randomly selects numbers and calls them out for a group of players who each have a card of random numbers in a grid. The players mark the numbers off their cards as they are called, and the objective is to mark a full line.
The primary difference between Tambola and U.S. bingo is that bingo cards are five by five, and Tambola cards are nine by nine. Bingo numbers are called with a letter to designate what column they can be found in, where Tambola cards are organized in tens. It is customary for Tambola numbers to be called with a clever rhyme for flavor. The game is usually won by marking a complete horizontal line, however, it can also be won with lines in different directions or by marking the entire card. Winners announce that they have won by standing and shouting "Tambola."
Tambola, like bingo, is often played for small amounts of money in large halls with dozens of players. It is incredibly easy to learn, but it is almost entirely predicated on chance. Because of this, it is often treated as a casual gambling game rather than a serious one.