Fun and games
Rock Paper Scissors
Pick rock, paper, or scissors and go against the computer. Scores, streaks, and the last few rounds stay visible so this feels more like a real session and less like a one-click novelty. Keyboard shortcuts also work (`R`, `P`, `S`).
Rock Paper Scissors
Rock Paper Scissors plays against the computer, keeping scores, streaks and a running record between sessions.
How to use it
- Choose rock, paper or scissors.
- See the computer's choice and the result.
- Watch your record and streak build.
The only unbeatable strategy
Game theory gives a clean answer: the optimal strategy is to play each option exactly one third of the time, at random. Against a perfectly random opponent no strategy does better than break-even, and playing randomly yourself cannot be exploited.
Against humans it is a different game, because humans are terrible at being random. Players avoid repeating the same throw, tend to open with rock, and often switch to whatever would have beaten their opponent's last move. Competitive players exploit exactly those tendencies, which is why the world championship is not settled by coin flip.
When it helps
- Settling a decision between two people.
- A quick game needing no equipment.
- Demonstrating mixed-strategy equilibrium in game theory.
- Testing whether you can actually play randomly, which is harder than it sounds.
Common mistakes
- Trying to be random by feel. Humans produce recognisable patterns and avoid repetition far more than chance would.
- Reading meaning into a streak. Streaks are expected in random sequences.
- Opening with rock against an experienced player, since it is the most common opening and they know it.
