In bingo, a shutter is the card or board printed with numbers that a player uses to keep track of the calls. As each number comes out of the bingo cage, the player marks the matching square, so the card shows at a glance which numbers have already been drawn. Shutters come in different sizes, colours and shapes depending on the venue, but they always do the same job.
The name comes from the motion of marking: closing and opening the little windows on a board looks a lot like shutters going up and down on the front of a building. Some halls also use oversized shutter boards so every player can double-check the drawn numbers if they think they have missed one or two.
The shutter in online bingo
Digital bingo replaces the physical shutter with automatic marking: the software daubs called numbers on every ticket a player holds and highlights the tickets closest to a win. Numbers come from an RNG rather than a cage, so a clear draw history and ticket view does the job of the hall’s big board.