How to play 75-ball bingo

In 75-ball bingo you play a 5×5 card: 24 numbers around a free space. Balls from 1 to 75 come out one at a time, and you cover every number you have. The first card to finish a row, a column or a diagonal wins the Line; the first card covered completely wins the Full card, and the game ends.

Everything else — the letters, the pot, the shouting — is detail. Here it is, exactly as it works in the Hall of Seshat.

Each column has its own range of numbers, and the letter above it tells you which: B holds 1–15, I 16–30, N 31–45, G 46–60 and O 61–75. That is why a ball is announced as “B-7” or “G-52”: the letter sends your eye straight to the right column. In the Russian and Ukrainian versions of the game the sign reads БИНГО and БІНГО, so the same ball shows up as «Г-52».

The N column has only four numbers, because the centre is a free space that counts as covered from the start. Numbers never repeat within a card, and their order inside a column is random, so two cards almost never match — there are about 5.5 × 10²⁶ possible cards. The arithmetic is on the card generator page.

• Line — any five in a row: one of the five rows, five columns or two diagonals, 12 ways in all. A line through the centre needs only four numbers. The Line takes 30% of the pot.
• Full card — all 24 numbers. It takes the other 70% and ends the game.

The pot is simply the price of every card in the game, the AI residents’ cards included, and nothing is taken off the top. If two or more cards complete a prize on the same ball, it is split equally between them. If both cards are yours, you collect both shares.

You can buy one to four cards for a game. Your numbers stay with you from game to game; “Other numbers” deals fresh ones for cards you have not bought yet. A game starts 20 seconds after the first card is bought, and while it runs you are already buying for the next one.

Each price comes in two kinds of hall, and they feel quite different.

AUTO: sit back and watch

The server covers your numbers the moment a ball comes out, so you cannot miss a win. A ball every 3 seconds; after the Line there is a 5-second pause so the whole hall sees who took it. You watch, chat and wait for the last number. This is the hall for talking, or for playing four cards without hunting for numbers.

MANUAL: mark and shout

Here you tap the numbers yourself and the hall only checks. When a line or the whole card is done, press BINGO! — or Space on a computer. Only marked numbers count: a number that came out but was never tapped does not help you. A ball comes every 8 seconds.

• The first correct shout wins. Everyone who shouts on the same ball shares: after the first shout the balls stop and the hall asks “Any more winners?” for 4 seconds.
• A false shout costs no debens, only time: the button rests for 5 seconds, 10 after a second mistake in the same game, then 20.
• Tapping a number that has not come out yet is harmless — the cell shakes and a note tells you so.
• AI residents shout 1.5 to 4.5 seconds after the ball that completed their card, and about one time in eight they doze off and shout a ball later. A sharp player beats them more often than the card count alone would suggest.
• After the 75th ball there are 10 seconds to shout. If nobody does, every completed card shares the prizes.
• Minimise the game for more than 2 seconds, lose the connection or leave the hall, and a helper plays your cards like an AI resident until you return.

Manual games give one and a half times the experience. During your first three, numbers you missed start blinking after 3 seconds; later you can switch the hint back on in the hall’s rules.

Here is one card and the first 23 balls of a game. Gold numbers are covered; the outlined column is the line that won.

By ball 12, G-47, the card had seven numbers, scattered all over it. Ball 20, B-9, left the middle row one short: 9, the free space, 47 and 75 were covered, and only I-29 was missing. But the line came from elsewhere. Ball 23, N-41, completed the N column — 38, 33, the free space, 41 and 45. Four numbers made a line, because the free space counts.

In an AUTO hall the Line would be paid at once. In a MANUAL hall the owner had until the next ball, 8 seconds, to tap 41 and press BINGO!, and anyone shouting on the same ball would share. Then the game carries on for the Full card. This card still needed 12 numbers, and with 11 to 14 cards in the hall the Full card falls between ball 64 and ball 71 in four games out of five.

We simulated 200,000 games of a typical hall: you with one to four cards, and two to five AI residents with one to three cards each — the way our server seats them. The table shows the average ball on which each prize went and your share of it.

So the draw in an AUTO hall takes about three and a half minutes; add the 20-second countdown and 8 seconds of results. A MANUAL game runs about nine minutes. Shared prizes are not rare: the Line is split in about 9% of games and the Full card in about 19%, because the last few balls often complete two cards at once.

• More cards, more chances — not better ones. Four cards out of fourteen win a prize about 29% of the time, one card out of eleven about 9%. Each card still returns its price on average, because the pot is shared fairly. Buy as many as you enjoy following.
• In MANUAL, more cards means more work. With one card, two balls out of three miss you completely. With four, only about one ball in five does: on average every ball lands on 1.3 of your cards. If 8 seconds a ball feels tight, play two cards or move to AUTO.
• The size of the hall matters more than anything you do. The more cards in the game, the earlier the prizes go. On a quiet night you face about ten AI cards; on a busy one, dozens.
• Watch the letter first. In MANUAL the letter above the column lights up for two seconds when a ball comes out. Scan that one column on every card instead of the whole grid.
• Shout fast, but not blind. A correct shout within a second or two beats most AI residents. A false one rests your button for 5 to 20 seconds — long enough for someone else to take the prize.
• No system changes the draw. The server shuffles all 75 balls before the first one comes out. Keep the numbers you like because you like them, not because they are “due”.