Code Crack
Crack the other code before yours falls. Best of 3 rounds.
Code Crack is a two-player Mastermind-style code-breaking game in which each player sets a secret 4-digit code and takes turns guessing the other's. A solid dot marks a right digit in the right place, a ring a right digit in the wrong place.
Each of you locks in a secret 4-digit code, then you take turns guessing the other's. Solid dots for right digits in the right place, rings for right digits in the wrong place: read the clues and crack it first.
Also known as Mastermind-style, Bulls and cows.
- How you hold it
- Face-off
- Match
- Best of 3 rounds
- Length
- About 2 to 3 minutes a round
- Play
- Friend or bot
How to play Code Crack: quick rules
About 2 to 3 minutes a round with 4 digits; 5 to 8 minutes for best of 3 with a friend. Full rules, options and bot levels are further down.
- 1Set your secret code behind the cover while the other player looks away.
- 2Take turns guessing the other code.
- 3A solid dot is a right digit in the right place; a ring is a right digit in the wrong place.
- 4Crack the code first to win the round.
Code Crack rules
Setting codes
- Each player sets a secret code of 4 digits from 0 to 9 (3 or 5 with the Digits option).
- By default every digit in a code is different; the keypad greys out digits you've already typed. With Digits can repeat on, digits may repeat.
- With a friend, the round's starter sets first behind a hand-over cover while the other player looks away, then the other player does the same. A locked code can't be changed.
- Against the bot, the bot's code is picked at random.
Guessing and the dots
- Take turns; the starter guesses first. A turn is one guess of a full code.
- Each guess gets one dot per digit: a solid dot for a digit that is right and in the right place, a ring for a digit that is in the code but somewhere else, and a faint dot for the rest.
- The dots are never in position order: solid dots come first, then rings, then faint dots. Working out which digit earned which dot is the puzzle.
- A repeated digit counts no more times than it appears in both codes.
- Guesses and their dots are public to both players; only the codes are secret. A guess one digit short of cracking stamps "Close!".
Winning a round
- Crack the code (every dot solid) to win the round. Turns are kept equal: if the starter cracks it, the other player still gets one last try on the same turn.
- If the second player cracks first, they win at once.
- Each player has 8 guesses with 3 or 4 digits and 10 with 5. If nobody cracks by then, the closest best guess wins: more solid dots first, then more rings.
- The loser of a round sets and guesses first in the next. The first round of a new match starts with a coin toss, and a rematch starts with the player who lost.
Ties
- If both players crack on the same turn, or the best guesses are exactly equal at the end, the round is replayed with new codes and the other player starts. A match never ends drawn.
Hints against the bot
- Playing the bot outside a tournament, on your guessing turn you can spend 20 coins on a hint. It shows the strongest next guess from your own clues, faintly in your next row, for two seconds. It never plays it for you.
- One hint per turn, and none with a friend, online or in a tournament.
Extras
- Probe
- On by default. Once a round each, type a single digit and ask whether it is in the code. The answer is a tick or a cross, and it uses your turn.
- Easy hints
- Off by default. Each guessed digit is also shaded and marked with a shape for right place, wrong place or not in the code, so new players can follow along.
- Clock
- Off by default. 30 seconds a turn. Run out while guessing and you skip; run out while setting and a random code is locked in for you.
Tips to win at Code Crack
- 1Make your first two guesses cover 8 different digits, like 0123 then 4567. The dots tell you which digits are in the code before you worry about order.
- 2Only guess codes that fit every clue so far. A guess that ignores an earlier clue wastes a turn.
- 3Remember the dots aren't in position order. Move one digit at a time between guesses to find out which digit earned the solid dot.
- 4When you set your code, avoid easy patterns like 1234 or a date; a random-looking code takes longer to crack.
Where Code Crack comes from
Code Crack is based on Bulls and Cows, a pencil-and-paper code-breaking game with numbers that is thought to date back a century or more. The same idea was later sold with coloured pegs as the board game Mastermind, first published in 1970.
Controls
Phone flat between you. Each player owns a half, and the far half faces the far player.
- A 12-key keypad sits at the acting player's end: digits, Delete and Enter. With a friend it moves to the other end behind the cover.
- Enter is a lock while setting your code and a tick when a guess is complete.
- Between turns with a friend, a hand-over cover fills the screen: the next player taps I'm ready while the other looks away.
- Your own code shows only in your rack; the other code is padlocks until the round ends.
Options
Every option is free. Defaults are marked.
| Option | Choices | What it does |
|---|---|---|
| Digits | 34 (default)5 | Code length; 8 guesses each for 3 or 4 digits, 10 for 5. |
| Digits can repeat | Off (default)On | |
| Rounds | 13 (default)5 | First to 1, 2 or 3 round wins. |
| Probe | On (default)Off | Extra: ask once a round whether one digit is in the code. |
| Easy hints | OnOff (default) | Extra: guess digits shaded and marked for new players. |
| Clock | OnOff (default) | Extra: 30 seconds a turn. |
Play Code Crack against the bot
The bot is a real code-breaker. It reads only its own guesses and their dots, never your code, and its own code is picked at random.
Easy
Often guesses at random, and otherwise only uses its last couple of clues.
Normal
Guesses codes that fit all its clues, though now and then it overlooks one. It uses its probe once early on.
Hard
Picks the guess that rules out the most codes and cracks a 4-digit code within its guesses almost every time.
Online, tournaments and hints
- Online
- PlannedCode Crack is turn-based and online play for it is planned, but not available yet. Today you play a friend on one phone, with a hand-over cover, or the bot.
- Tournament
- Can be drawn in a tournamentIn a tournament it is best of 3 rounds with 4 different digits, Probe on, Easy hints and Clock off, and no hints.
- Hints
- Stuck against the bot? A hint lights up the strongest move for a few coins. Never with a friend, online or in a tournament.
Coming soon
- Online play. Play Code Crack against a friend on another phone, with both codes held on the server and a turn clock.
How it feels
- A soft click on every key and a padlock snap as you lock your code.
- Clue dots drop in one after another, with a rising peg sound for each solid dot.
- A short sting and a "Close!" stamp when you're one digit away.
- The lock opens with a fanfare on "Cracked!", and both codes flip open at the end of the round.
Accessibility
- The dots differ by shape, filled, ring or faint, never by colour alone, and each group is read out as "2 right place, 1 right digit".
- Easy hints marks use different shapes too.
- No clock unless you turn it on, and every input is a tap, so one-handed play works.
- With reduced motion on, dots appear without the pop and stamps fade.
Code Crack questions
Each player sets a secret code, then you take turns guessing the other's. After each guess, solid dots show right digits in the right place and rings show right digits in the wrong place. The first to crack the code wins the round.
Yes, it is a Bulls and Cows or Mastermind-style code-breaking game with numbers, played head to head: you each crack the other's code.
Yes. A hand-over cover hides your code while the other player sets theirs and between turns.
No. If the starter cracks the code, the other player still gets one last try on the same turn, so both always have the same number of guesses.
Yes. The bot is a real code-breaker. Choose Easy, Normal or Hard.
Not yet. Code Crack is turn-based and online play for it is planned, but not available yet. Today you play a friend on one phone, with a hand-over cover, or the bot.
Play Code Crack on one phone
Free on Android. Sit face to face, or take on the bot on Easy, Normal or Hard.
