How unique bingo cards work
What "every card is different" really means, how many words you need, and why a short list makes everyone win at once.
Unique isn't only a different order
Many generators shuffle the same words into a new order and call each card unique. If your list has exactly as many words as the card has squares, every card holds the same words, and every player marks a square on every call. Lines then appear on many cards at once, and the game ends in a crowd of winners.
This maker counts two cards as the same if they hold the same set of items, whatever the order. Each new card is checked against all earlier cards and redrawn if it matches one. The result: every card in your batch has its own combination of words.
How many different cards are possible?
The number of different word sets is "n choose k", where n is the number of words in your list and k is the number of squares to fill. It grows very fast:
| Card | Words in list | Different cards possible |
|---|---|---|
| 3×3, free center (8 squares) | 10 | 45 |
| 3×3, free center (8 squares) | 12 | 495 |
| 4×4 (16 squares) | 18 | 153 |
| 4×4 (16 squares) | 20 | 4,845 |
| 5×5, free center (24 squares) | 26 | 325 |
| 5×5, free center (24 squares) | 30 | 593,775 |
| 5×5, free center (24 squares) | 40 | more than 60 billion |
The card maker shows this number live under your word list, and it refuses to make more cards than your list allows, so you never get hidden repeats.
Unique cards can still look similar
With 26 words on a 5×5 card, there are 325 possible cards, but any two of them share at least 22 words. The cards are different, yet the game will still feel crowded. As a rule of thumb:
- Have at least 1.4 times as many words as squares for a lively game (35 words for a 5×5 card).
- For big groups (over 50 players), aim for twice as many words as squares.
- For very young children who need a quick win, a short list is fine on purpose.
Classic 75-ball cards
Traditional number bingo puts 1–15 under B, 16–30 under I, 31–45 under N, 46–60 under G and 61–75 under O, with a free center. That allows about 111 quadrillion different sets of numbers, so repeats are never a practical problem. Choose "Classic numbers 1–75" in the maker to print them.
Reprinting the same set
The game code at the bottom of each card seeds the shuffle. Enter the same word list, the same settings and the same code, and the maker rebuilds exactly the same cards in the same order. Card 12 stays card 12, which makes it easy to replace a lost card or to check a winner.
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