About Bingo:

Bingo is a game of chance played with randomly drawn numbers which players match against numbers that have been pre-printed on 5x5 matrices. The matrices may be printed on paper, card stock or electronically represented and are referred to as "cards." Many versions conclude the game when the first person to achieve a specified pattern from the drawn numbers. The winner is usually required to call out the word "Bingo!", which alerts the other players and caller of a possible "win". All wins are checked for accuracy before the win is officially confirmed at which time the prize is secured and a new game is begun. In this version of bingo, players compete against one another for the prize or "jackpot".

Alternative methods of play try to increase participation by creating excitement. Since its invention in 1934, modern bingo has evolved into multiple variations, with each jurisdiction's gambling laws regulating how the game is played. There are also nearly unlimited patterns that may be specified for play. Some patterns only require one number to be matched, up to cover-all games which award the jackpot for covering and entire card and certain games award prizes to players for matching no numbers or achieving no pattern. See "Variations" for more details.

The most common Bingo cards are flat pieces of cardboard or disposable paper which contain 25 squares arranged in five vertical columns and five horizontal rows. In addition, Dual dab, or "double-action" cards have two numbers in each square. Each space in the grid contains a number, except there may be one or more "Free" spaces, which are considered filled. Typically the game is played utilizing 75 numbers. The letters B, I, N, G, O are pre-printed above the five vertical columns, with one letter appearing above each column. The center space may be marked "Free". The printed numbers on the card commonly correspond to the following arrangement: 1 to 15 in the B column; 16 to 30 in the I column; 31 to 45 in the N column; 46 to 60 in the G column and 61 to 75 in the O column. In U-Pick'Em bingo and other variants of bingo, players are issued three 25 number cards which contain all 75 numbers that may be drawn. Players then mark which numbers they wish to play and then daub those numbers according to the numbers drawn.

There are about 5.52*1026, (exactly 155 × 145 × 135 × 125 × 114) possible arrangements of the numbers on a bingo card.

The most chips one can place on a Bingo board without having a Bingo is 19, not counting the free space. In order for this to happen, only one empty cell can reside in each row and each column, and at least one empty cell must be in each diagonal, for instance:

O O _ O O
O _ O O O
O O F O _
O O O _ O
_ O O O O

Note: in addition to a straight line, many bingo halls consider other patterns as a valid "bingo", usually in special games. For example, in the illustration above, the 2x2 square of marked squares in the upper right-hand corner would be considered a "postage stamp". Another common special game requires players to cover the four corners.