Master Number
Master Number is a number-guessing deduction game for 2–5 players that takes about 10 minutes. Everyone races to crack the same secret number with hits and blows. Free in your browser, no sign-up.
Play over time
Master Number in 30 seconds
- Set upThe game picks a secret number of four different digits: the Master Number.
- ClueEach player is shown one correct digit: their Open Number.
- Take turnsGuess in turn; everyone sees the hits and blows for each guess.
- WinThe first player to guess every digit wins.
At a glance
| Item | This game |
|---|---|
| Players | 2–5 players |
| Play time | About 10 min |
| Type | Board |
| Ranked play | No |
| Practice against the CPU | Yes |
| Price | Free (no account needed) |
| Rights holder | A public-domain classic game |
| Last updated | 2026-09-18 |
How to play Master Number online with friends
- Tap "Play with friends"A party is created with a 6-character code. No account is needed.
- Send a link or QR codeShare it on LINE, or just read the code aloud.
- Everyone opens it in a browserOnce 2–5 players have joined, the host taps "Start".
Rule highlights
Setup, play, winning, and house rules
Setup
- For 2 to 5 players. Playing alone, you face the computer.
- The game picks a secret number (the Master Number) of different digits from 0 to 9. It has three to five digits; the default is four. It may start with 0.
- With Open Numbers on, each player is shown one correct digit in its place. With more players than digits, some players know the same digit. You cannot see which digit anyone else knows.
How to play
- Players guess one at a time in seat order. Enter the right number of different digits and press OK.
- Each guess shows how many digits are right and in the right place (hits) and how many are right but in the wrong place (blows). Every guess and result is visible to everyone.
- Each guess has a 60-second limit. When time runs out the turn passes with no guess (you can switch the limit off).
- Your Open Number is always a hit when you include it. Holding it back gives the other players fewer clues.
Winning
- The first player to guess every digit of the Master Number wins.
- If nobody cracks it within 100 guesses, the game is a draw.
House rules
| Name | Description | Default | Changeable |
|---|---|---|---|
| Digits | Choose three to five digits. Three is best for your first game. | 4 digits | Can be changed |
| Open Numbers | At the start, show each player one correct digit. | On | Can be changed |
| Time limit | Time allowed for each guess. When it runs out, the turn passes with no guess. | 60 seconds | Can be changed |
Recommendations
Play this game once to write one.
Send feedback or a bug about this game
Request a setting for this game
We publish the feedback you send and what we do about it here
FAQ
How many can play?
2 to 5 players. On your own, you can play against the computer.
How is it different from Hit & Blow?
Both narrow down the answer with hits and blows. Master Number uses digits instead of colours, lets 2 to 5 players race for the same answer, and gives each player one secret digit from the start (the Open Number).
Is it free?
Yes. It is free and runs in your browser with no sign-up.
Can I play on a phone?
Yes. No app is needed — just open it in a browser. You can join the same party as people on a PC or tablet.
Can two people play?
Yes. This game supports 2 or more players.
Can we play without being online at the same time?
Yes. Choose “Turn-based (told each turn)” and you can make one move whenever you like. We tell you when it is your turn. A table ends automatically, with no winner or loser, after 45 days without a move.
Rights holder and physical edition
This is a public-domain classic game. The rules follow the standard reference rules.
Related games
Same type (Board)
Same player count
Last updated 2026-09-18 · Run by Qdan, Inc.