Rock paper scissors against the computer
Rock paper scissors is the universal tie-breaker: no board, no dice, no arguments. With this tool you play against the computer right inside your browser. You tap rock, paper or scissors, the machine picks its move at the same moment, and you instantly see who wins the round. A scoreboard adds up your wins, losses and ties so you always know how the game stands.
The computer’s move is not rigged and it does not “read” yours: it is drawn with crypto.getRandomValues, the browser’s cryptographic generator, using rejection sampling so that rock, paper and scissors are exactly equally likely (one in three). You cannot predict it, and it cannot predict you.
How the game works
Each player picks one of three options at the same time. The rules of who beats whom form a perfect loop: nothing always wins and nothing always loses.
| Your move | Beats | Loses to |
|---|---|---|
| Rock 🪨 | Scissors ✂️ | Paper 📄 |
| Paper 📄 | Rock 🪨 | Scissors ✂️ |
| Scissors ✂️ | Paper 📄 | Rock 🪨 |
The idea is easy to remember: rock crushes scissors, scissors cut paper, and paper wraps rock. If both players choose the same option, it is a tie and you play another round.
How to use the tool
- Tap the big rock, paper or scissors button.
- The computer “hesitates” for a moment and then reveals its move.
- The result appears: you win, you lose or it is a tie, with a note on what beat what.
- The scoreboard records the round. Keep playing as many times as you like.
- Tap Reset scoreboard to start over from zero.
Everything runs with no connection to any server: once the page has loaded you can play even offline.
Example
You choose scissors ✂️. The computer plays paper 📄. Since scissors cut paper, you win the round and the scoreboard moves to 1 win. Next you pick rock 🪨 and the computer also plays rock: a tie, nobody scores a win but the tie counter rises to 1. Third round: you play paper 📄 and the computer scissors ✂️; scissors cut paper, so you lose. Final score: 1 win, 1 loss, 1 tie across 3 rounds.
Is there a winning strategy?
Against a perfectly random opponent, like this computer, no move is better than another: your chance of winning is one third, losing another third, and tying the remaining third, whatever you pick. Against people it is different, because humans follow patterns: many open with rock, tend to repeat the move that just won, and avoid throwing the same option three times in a row. Human tournaments exploit those tendencies, but here the cryptographic randomness cancels them out completely.
Frequently asked questions
Does the computer cheat or see my move?
No. The computer picks its move independently with crypto.getRandomValues and does not react to yours. All three options are equally likely to come up, so there is no edge and no bias.
Who wins each combination?
Rock beats scissors, scissors beat paper, and paper beats rock. If both players choose the same option, it is a tie. It is a closed loop where every option beats one and loses to another.
Can I play offline?
Yes. Once the page has loaded, the whole game runs inside your browser. Nothing is sent to or stored on any server, and the scoreboard lives only on your screen until you reset it.
Why do I sometimes lose several rounds in a row?
Because it is pure chance. With three equally likely outcomes, streaks of wins or losses in a row are normal and do not mean the game is rigged. The more rounds you play, the more the scoreboard evens out toward a third in each category.