Each online bingo site has its own spin on rules and procedures, but some things are common to virtually all sites that allow bingo fans to play the game over the Internet. For online bingo sites, just as in bingo halls, players may purchase up to a certain number of cards for one game. Some online bingo sites allow players to have as many as 100 cards in use at the same time.
Basic game play differs depending on whether a player is playing 75-ball bingo, common in the U.S., or 90-ball bingo, the game more commonly played in the UK. Both types are available in online bingo halls.
In 75-ball bingo, an online caller draws letter-number combinations at random and announces them. Players need to scan their cards for squares that match the combination just called. This is not as tricky as it may sound, since there are only five letters used. When the caller announces, for example, B-3, even players with dozens of cards can scan them quickly for a 3 since they only need to look in the B column of each card.
In 90-ball bingo, no letters are used. Callers announce numbers only, and players scan their cards for those numbers, which appear in predictable locations, with, for example, the numerals 1-9 only appearing in locations on the first vertical column of a 9×3 bingo card.
One of the most important rules associated with cards is the winning pattern. Players need to be aware of what conditions they must get in order to win. As they mark their cards to indicate letter-number combinations that have already been called out, various patterns may begin to emerge. Whether these constitute a winning pattern or not depends on the game being played.
Simple forms of bingo require that players mark a straight line across the card or that they achieve a “coverall” or “full house,” which refers to every number on the card being marked. Once a win has been achieved, the player must announce “Bingo!” to the room using the controls provided by the online interface. If a player has a bingo but does not announce it, another player may later announce his own and win the prize for that round.