The game is designed for two, three or four players. The computer makes a random secret 4-digit number with non-repeating digits. The player who starts the game by luck, makes the first attempt to guess the number. This is one turn of a player. The computer reports in response how many digits are guessed without and are at the wrong place of the secret number (that is, the number of cows) and how many are guessed right up to the position in the secret number (that is, the number of bulls).
For example:
The secret number «3219» is made.
Try: «2310».
Result: two «cows» (two digits: «2» and «3» — are guessed at incorrect positions) and one «bull» (one digit «1» is guessed right up to the position).
Players make attempts to guess by turns. The winner is the one who guesses the number first.