Rock Paper Scissors

Purpose

Settle a quick match on your own, or play several rounds and keep score.

How to use

1. Pick rock, paper, or scissors.
2. Watch the computer's move settle.
3. Check the result and the win/draw/loss score.
4. Pick again for the next round.

People cannot play at random

The optimal strategy is to play each of the three options exactly a third of the time, completely at random. Do that and your win rate is locked at one in three no matter what the opponent does.

The problem is that humans cannot generate randomness. Even when you feel like you are not thinking, measurable habits appear: repeating a winning move, switching after a loss, opening with rock more than a third of the time, and almost never playing the same move three times running.

This tool does not look at your choice

The computer's throw is generated from unbiased randomness independently of what you selected. It does not read your pick and counter it, which is why the win rate converges on one in three over time.

Previous rounds have no effect either. Each round is fully independent, so a winning or losing streak does not change the odds of the next one.

Using it to spot your own habits

If you lose often against people, your patterns may be readable. Playing a long run here reveals how heavily you lean towards particular moves in the running score.

The reliable way to remove patterns is to stop deciding with your own head. Prepare a random sequence in advance and follow it, and no amount of analysis will push an opponent above a third.

Streaks in short sessions are normal

Losing three in a row has about a 3.7 percent chance, which is common, and five in a row is about 0.4 percent, which is uncommon but not rare. Short sessions exaggerate streaks.

The real ratio only appears across many rounds. The tool keeps a running record of wins, losses, and score, so playing enough shows the convergence towards one in three.

A poor fit for picking one from a group

With three or more players throwing at once, all three moves appearing means nobody wins, and ties become common. The tie rate rises with group size, and past five players most rounds resolve nothing.

For selecting one person from a group, a name picker or a wheel resolves in one step regardless of size. Rock paper scissors works best with exactly two players.

Examples

• Settle a quick match
• Decide between two people
• A short break game
• Play several rounds

Notes

• The computer's move uses unbiased browser randomness.
• It is a casual game; agree on rules for important decisions.

FAQ

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