How to Win at Rock Paper Scissors: What the Research Says
In theory, rock paper scissors cannot be beaten. If both players choose completely at random, each wins a third of the time, loses a third and draws a third. In practice, people are terrible at being random, and that is exactly where a strategy comes from.
Why random play cannot lose (or win)
Each throw beats one option, loses to one and ties with one. Against a perfectly random opponent, no choice is better than another, so over many rounds every strategy averages out to a third wins, a third losses and a third draws. Game theorists call this the equilibrium. The moment a player stops being random, though, their choices become predictable.
What the research found: win-stay, lose-shift
In 2014 researchers at Zhejiang University in China published a study in Scientific Reports in which several hundred students played hundreds of rounds of rock paper scissors for small cash rewards. Overall the choices looked close to random, but round by round a clear pattern appeared:
- Winners tended to repeat the throw that had just won.
- Losers tended to switch, and usually to the next option in the order rock, paper, scissors. A player who lost with rock was more likely to move to paper.
The authors called this a "win-stay, lose-shift" pattern. It is a very human reaction: keep doing what works, change what does not.
How to use it
After you win
Your opponent just lost, so they are likely to shift to the throw that beats the one they used. Assume they will, and play the throw that beats their likely next choice. In practice: if you won with paper against their rock, they may move to paper next, so scissors is a good answer.
After you lose
Your opponent just won, so they are more likely to repeat. Play the throw that beats what they just used. If their scissors beat your paper, try rock.
After a draw
There is no strong pattern after a tie, so this is the best moment to be genuinely unpredictable.
Other common habits
Some habits are widely repeated by players and tournament organisers, but have weaker evidence behind them, so treat them as tendencies rather than rules:
- Many first-time players open with rock, so paper is a popular opening.
- People rarely throw the same option three times in a row, because it does not feel random.
- When players announce a throw to bluff, they often do not follow through.
Can a computer beat you?
A computer that plays truly at random cannot be beaten in the long run, and cannot beat you either; it just wins about a third of the time. Our rock paper scissors game plays this way, using your browser's cryptographic random number generator, so it has no patterns for you to exploit. That makes it a fair way to settle a decision, and a good way to test whether you can stay unpredictable yourself.
Settling a real decision
For a quick, fair decision between two people, best of three is the usual rule. If you would rather skip the strategy, a coin flip or the Yes or No Button gives a plain 50/50 answer.
Sources
- Wang, Z., Xu, B. and Zhou, H.-J. (2014). Social cycling and conditional responses in the Rock-Paper-Scissors game. Scientific Reports, 4, 5830.
FAQ
Is there a way to always win rock paper scissors?
No. Against a truly random player every throw wins only a third of the time. You can only gain an edge against people, because people follow patterns.
What is the best first move in rock paper scissors?
Many beginners open with rock, so paper is a popular first throw, but this is a habit rather than a proven rule.
What does win-stay, lose-shift mean?
It is the pattern found in a 2014 study: players who win tend to repeat their throw, and players who lose tend to switch to the next option.
Can you beat a computer at rock paper scissors?
Not if it plays truly at random. A random computer wins, loses and draws about a third of the time each, no matter what you do.