Bulls and Cows: The Number Game Wordle Descends From

Bulls and Cows is a 4-digit code-breaking game: guess the secret number, then use bulls and cows feedback to narrow what can still be true. A bull means the right digit in the right place. A cow means the right digit in the wrong place.

People compare it to Wordle because both games turn a wrong answer into useful information. You are not guessing wildly after the first move. You are testing a possibility, reading the reply, and crossing off a large part of the search space. Wordle uses letters and colours; Bulls and Cows uses digits and counts. The mental rhythm is very close.

The older paper-and-pencil version is usually for 2 players. Each player writes a secret code, then they take turns guessing. Online, the computer supplies the secret code and you solve it alone. There are few rules, but many possible choices. A careless guess can tell you almost nothing. A good guess can split the remaining possibilities sharply, which is why the game still feels clean after hundreds of plays.

What is Bulls and Cows, and why do people compare it to Wordle?

Bulls and Cows is a code-breaking game played with digits instead of letters. In the standard form, the secret is a 4-digit code made from different digits. You make a 4-digit guess, then receive a clue made of 2 numbers: bulls and cows.

The comparison with Wordle is fair, but it needs care. Wordle did not invent clue-based guessing. Bulls and Cows is an older number guessing game with the same core pressure: each answer tells you what is fixed, what is present but misplaced, and what can be ruled out. Wordle turns that into green, yellow and grey letter tiles. Bulls and Cows gives you counts.

The exact historical path from paper Bulls and Cows to modern word games is not proved by the rules alone. The evidence is strongest in the structure. You choose a candidate, receive partial feedback, and use that feedback to reduce the set of possible answers. That is the family resemblance people notice.

The feel is different, though. Wordle gives visible letter positions. Bulls and Cows hides which digits caused the clue. If you guess 1234 and receive 1 bull and 1 cow, you know 2 of those digits are in the code, but you are not told which 2. That single omission is where many deductions start.

How do you set up a game and what does each clue mean?

For a traditional 2-player game, each player secretly writes a 4-digit code using different digits. The secret must stay hidden until the end. Players then take turns guessing each other’s code and giving feedback after every guess.

For a solo browser game, the setup is shorter: the game chooses the secret code, and you start guessing. There is no board in the chess sense. The record of play is a list of guesses with feedback beside each one. That list matters because every earlier clue remains binding.

• Bull: one digit is correct and in the correct position. If the secret is 4279 and the guess is 1234, the digit 2 is a bull.
• Cow: one digit is correct but in a different position. With the same secret, the guess 9123 has 2 cows: 9 and 2 are present, but neither is placed correctly.
• 0 bulls, 0 cows: none of the guessed digits appears in the secret. This is not a wasted turn; it can remove 4 digits at once.
• 4 bulls: the whole code is correct. The game is over.

The feedback is a count, not a label on each digit. That is the key rule many new players miss. If you guess 5678 and get 1 bull and 2 cows, you know 3 digits from the guess are in the answer, but you do not know which one is the bull from that clue alone.

There is no scoring in the basic rules. A clue is not a score, and cows are not worth less than bulls. They are information.

What does a turn look like from guess to feedback?

1. Choose a legal 4-digit guess. Use different digits. Early guesses are often chosen to test a spread of digits rather than to be a serious attempt at the exact answer. A guess such as 0123 asks about 4 digits at once.
2. Submit the guess. In a paper game, you say or write it for the other player. In a browser game, you enter it and the game checks it against the hidden code.
3. Read the bulls count. Bulls tell you how many digits are already in the correct positions. A result of 2 bulls does not tell you which 2 positions are right. It only tells you that exactly 2 positions in that guess match the secret.
4. Read the cows count. Cows tell you how many other digits appear in the secret but sit in the wrong positions in your guess. Bulls and cows are counted separately, so a single digit cannot be both.
5. Compare the new clue with every old clue. This is the actual work. If one guess says a digit is absent, later guesses must respect that. If another clue proves a digit is present, you start testing its possible positions.
6. Make the next guess to answer a question. A strong turn usually tests a small doubt: whether 7 belongs in the second position, whether 4 is present at all, or whether two known digits need to be swapped.

A turn is short, but it should not be automatic. The best guesses are not always the ones that look closest to the answer. Sometimes a deliberately shaped guess gives cleaner information than a hopeful near miss.

How do you win, and what happens when you get it wrong?

You win Bulls and Cows by guessing the exact secret code. In clue terms, that means your guess receives 4 bulls. Since the code has 4 positions, 4 bulls can only mean every digit is correct and every digit is in the correct place.

A wrong guess does not end the game under the normal rules. It produces feedback, and that feedback becomes part of the evidence for the next guess. If you guess 1357 and receive 0 bulls and 2 cows, you have not failed. You have learned that exactly 2 of those digits are in the code, and both are in different positions from the ones you tried.

There are no points in the basic game. Some players keep an informal score by counting guesses, with fewer guesses treated as a better solve, but that is a comparison method rather than a win condition. The formal end is simple: the game stops when the secret is found.

The main way to get it wrong is not a single bad guess. It is ignoring an old clue. If a later guess contradicts something already known, the whole chain of reasoning starts to wobble. Careful players write down candidates or mentally keep only the codes that satisfy every clue so far.

Why does this number guessing game still hold up?

• The rules fit in a minute. Four positions, bulls for right place, cows for wrong place, 4 bulls to win. You can teach it without a diagram, a deck of cards, or a long example.
• The clues are exact. Bulls and cows feedback contains no luck once the secret is chosen. If a clue says 1 bull and 1 cow, that statement is precise. Your job is to use it properly.
• It rewards restraint. New players often chase the answer too early. Better play comes from asking useful questions, even when the guess itself is unlikely to win immediately.
• It has tension without noise. There are no special powers, bonus rounds, timers, or hidden scoring systems in the basic game. The pressure comes from your own narrowing list of possibilities.
• It scales naturally. If you enjoy the 4-digit version, 5-Digit Bulls and Cows asks the same kind of thinking with a larger search space. Mastermind and Super Mastermind move the idea into coloured-code form.
• It makes mistakes visible. A contradiction usually shows up as soon as no candidate seems to fit all the clues. That sting is useful. Next game, you become more careful with every count.

Frequently asked questions

Final thoughts

If a friend asked why Bulls and Cows is worth their time, I would tell them to play slowly for the first few games. Do not treat it as a race to type numbers. Treat each guess as a small experiment, because that is where the pleasure is.

The nicest moment is not always the final 4 bulls. Often it comes one turn earlier, when the clues stop feeling like fragments and start behaving like a trap closing around one answer. You realise a digit cannot go in the first place, must be in the third, and forces another digit out of the fourth. The code has not appeared by magic. You have cornered it.

That is also why the game survives without decoration. It gives you enough information to be fair, but not enough to be comfortable. You will make guesses that look sensible and later find they answered the wrong question. You will also find the occasional clean line where every clue does useful work.

For such a small ruleset, Bulls and Cows has a sharp memory. It remembers every lazy assumption you made. It also rewards the quiet, satisfying habit of proving one thing at a time.