Bingo card maker: type your list, print the cards and the call list

What is on the paper

• The cards, each a square of 3, 4 or 5 squares a side, with one thing from your list in each square, written the way you typed it.
• BINGO at the top of every card, or a few words of your own if you type them.
• A free square in the middle, in black with the word FREE, on cards of 3 or 5 a side, unless you untick it. A card of 4 a side has no middle square.
• The set number and the card number in small print under every card: Set 4821 · Card 7.
• 1, 2 or 4 cards on a sheet of paper. With 2 or 4, the cards are cut apart with scissors; the page draws no cutting lines.
• The call list after the cards: your whole list, in an order drawn by chance, numbered, with a box to tick before each line.

Your list

• Up to 75 lines, 24 characters each. A longer line is cut at 24 characters. Lines after the 75th are left out, and the page names them.
• Anything you can type goes in: words, names, numbers, short phrases, accents and Ñ. Numbers are treated like words: any number can land in any square.
• A line that is there twice is used once, capitals aside: Cat and CAT are the same line. The page names the one it left out.
• The list has to be at least as long as a card has squares to fill: 8 or 9 lines for a card of 3 a side, 16 for 4, 24 or 25 for 5. With fewer, the page says how many more it needs.
• Short words are written large and long lines small, so each fits its square. On the smallest cards (5 a side, 4 on a sheet) a long line is small print.

How the cards are dealt

• Each card gets its own draw from the list, by chance. No line is on one card twice.
• No two cards of a set are the same. A card that comes out the same as an earlier one, square for square, is dealt again.
• A longer list makes the cards differ more. When the list is just as long as a card has squares to fill, every card holds the same things in different places, and the page says so.
• Every line of your list is on the call list, also the ones that landed on no card.
• Every set has a number from 1 to 9999. The page picks one by chance when it opens and when you press Another set. You can also type one.
• The same number with the same list and choices gives the same cards every time, on any device, and the same call list. Card 7 of a set is the same card whether you print 7 cards or 40. So a lost card can be printed again another day: type the same list in the same order, set the same choices and the set number from under the card.

What this page does not do

• It does not say who has won, and it does not check a card. What counts as a win (a row, a column, the whole card) is for the people playing to agree on.
• It cannot be played on the screen: the cards are for paper. The page shows one card at a time so you can look them over.
• It has no lists of its own beyond 30 example words and the numbers 1 to 50, and it does not say which list suits which age or group. You choose.
• It does not sort numbers into columns: a number is a line of the list like any other.
• It keeps nothing: close the page and the list is gone.
• It has been tried in one browser’s print preview (Chromium, saved as PDF), not on paper from a real printer.

Every time the page is built, a program checks 89 examples worked by hand. Then it types 2,000 made-up lists, some with accents, signs, lines that repeat and lines that are too long, and writes the cards and the call list the way the page prints them. A second reader, written separately, takes the squares back off the paper. It checks that every card is a square of the size asked for, that the free square is in the middle and nowhere else, that every other square holds a line of the list and no line is on a card twice, that no two cards of the set are the same, that no sheet holds more cards than asked, that the call list holds every line once, and that the first cards stay the same when more cards are asked for. That checks the page’s own work, not how any game goes.