These games were traditionally played in specific countries but have become more globalised online. Most types of online bingo revolve around one of the above formats. Most games are from the traditional 90, 75 and 80 ball varieties, with 30 ball being a relatively new addition. The numbers refer to the number of squares on the grid found on the bingo cards used to play. Straight line pattern games As well as the ball games, there are online bingo varieties that revolve around patterns. These allow players to win by creating straight lines on their cards that go up and down, left and right, or even diagonally. Shape pattern games These games require players to create a particular shape on their card to win. The shapes are announced before the games start and there are lots of different shapes to play, including triangles, crosses, squares and more. Letter pattern games Similar to the above two formats, letter patterns require players to mark off patterns in the shape of letters of the alphabet.