Rock Paper Scissors – Play Against the Computer

Rules of rock paper scissors

Each player chooses one of three hand shapes at the same time. Rock crushes scissors, scissors cut paper and paper covers rock. If both players pick the same shape the round is a draw. Because every choice beats one option and loses to the other, no single move is best – which is exactly why the game is used all over the world to settle small decisions fairly.

Game modes

Play a single round, a best of 3, 5 or 7 match (the first player to win the majority of rounds takes the match) or endless mode where you simply try to build the longest winning streak. Your overall win-loss-draw record and best streak are saved in your browser.

Random vs Smart computer

The Random opponent picks each shape with equal probability. Against it, mathematically, every strategy wins about one third of the time, loses one third and draws one third – it is pure luck. The Smart opponent keeps a short memory of your recent choices and looks for patterns: which shape you play most often and what you tend to play after a certain move. It then plays the shape that beats your most likely next move. If you always play rock, it will notice very quickly.

Strategy tips

• Be unpredictable. The only unbeatable strategy over many rounds is to choose truly at random. People are bad at this – we avoid repeating ourselves and fall into cycles.
• Watch for your own habits. Many players switch after losing and repeat after winning. The Smart computer can exploit that.
• Use the Smart mode as a trainer. If you can stay level with it over 30 rounds, you are doing well at being random.
• Against humans, players often open with rock, so paper is a common first move – but an experienced opponent knows that too.

Controls

Tap the big buttons, or use the keyboard: R or 1 for rock, P or 2 for paper and S or 3 for scissors. The game works on phones, tablets and computers, needs no download and keeps working offline after the first visit.

FAQ