Knockout Dice Game: Rules and the Safest Number
Knockout is a two-dice game where every player picks a “knockout number” before the game starts. You roll and add up your points, but the moment your two dice add up to your own knockout number, you are out. It is quick to learn, it gives young players lots of adding practice, and it has one real decision: which number to pick.
What You Need
- Two six-sided dice, or our Dice Roller set to two dice.
- Paper and a pencil to keep score.
- Two or more players.
Who Goes First
Pick the first player at random with our Random Name Picker, or let everyone roll one die with the Dice Roller; the highest roll starts. In this game going first also means choosing your knockout number first, so a fair start matters.
How to Play
Rules vary between families and classrooms. This is a common way to play:
- Choose your knockout number. Each player picks 6, 7, 8 or 9 and writes it down. Several players may pick the same number.
- Take turns rolling two dice. Add the total to your score.
- Knocked out. If your two dice add up to your own knockout number, you are out of the game. The roll does not score.
- Other players’ numbers do not hurt you. Only your own number knocks you out.
- Winning. The first player to reach 100 points wins. If everyone else is knocked out first, the last player left wins.
Which Knockout Number Is Safest?
Two dice make 36 equally likely results, and some totals come up more often than others. In the table, “Ways” is how many of the 36 results give that total, “Chance” is the chance per roll of being knocked out, and “Rolls (avg)” is how many rolls a player lasts on average, counting the roll that knocks them out. These numbers are exact.
| Number | Ways | Chance | Rolls (avg) |
|---|---|---|---|
| 6 | 5 of 36 | 14% | about 7 |
| 7 | 6 of 36 | 17% | 6 |
| 8 | 5 of 36 | 14% | about 7 |
| 9 | 4 of 36 | 11% | 9 |
7 is the most common total with two dice, so it is the riskiest pick. 9 comes up in only 4 of the 36 results, so it is the safest of the four. 6 and 8 sit in between, with the same chance. To see why 7 is the most common total, read our dice probability guide.
How Much Does Your Choice Matter?
We simulated 200,000 games for each number. “Reach 100 alone” is how often a single player gets to 100 points before being knocked out. “Win, 4 players” is how often each number won a four-player game where the players chose 6, 7, 8 and 9 and rolled in that order. These are simulated estimates.
| Number | Reach 100 alone | Win, 4 players |
|---|---|---|
| 6 | about 12% | about 24% |
| 7 | about 7% | about 18% |
| 8 | about 11% | about 24% |
| 9 | about 17% | about 34% |
Reaching 100 is hard with any number, so most games end with the last player standing. A safe number helps a lot: in our four-player games, the player on 9 won about one game in three, while the player on 7 won fewer than one in five. A 9 also scores a little less per roll, but staying in the game matters far more.
Tips
- Pick 9 if you can. It is the safest choice. If 9 is taken and numbers must be different, 6 or 8 are next best.
- Avoid 7. It knocks you out one roll in six.
- Let late pickers choose different numbers. If everyone picks 9, the game is fair again, so some groups make every player pick a different number to keep it interesting.
- Make it a lesson. Before playing, ask the class which number they think is safest. After a few games, count how often each total came up.
Variations
- Different numbers only: each player must pick a different knockout number. The first player to pick has an advantage, so choose the order at random.
- Wider range: allow knockout numbers from 2 to 12. A 2 or a 12 comes up in only 1 of 36 rolls, so set a rule that those numbers score half.
- Rounds instead of 100: play a set number of rounds; knocked-out players keep the points they had, and the highest score wins.
- Team Knockout: teams share one knockout number and one score, and team members take turns rolling.
Like games where one unlucky roll can end everything? Try Skunk. You will find more ideas in our list of easy dice games and our classroom games.
Where the Game Comes From
Knockout is a simple folk dice game played in homes and classrooms, and it often appears in collections of maths games. We could not find a reliable record of who invented it.
FAQ
How do you play Knockout with dice?
Each player picks a knockout number from 6 to 9. Players take turns rolling two dice and adding the total to their score. If you roll your own knockout number, you are out. The first to 100 points, or the last player left in, wins.
What is the best knockout number?
9 is the safest of 6, 7, 8 and 9, because only 4 of the 36 two-dice results add up to 9. 7 is the riskiest, with 6 of 36.
How likely is it to roll a 7 with two dice?
6 of the 36 results add up to 7 (1+6, 2+5, 3+4, 4+3, 5+2 and 6+1), so the chance is 1 in 6.
Can several players have the same knockout number?
In the usual rules, yes. Some groups ask every player to pick a different number to make the game less even.
Can you play Knockout with an online die?
Yes. Set our free Dice Roller to two dice and keep score on paper.