How to Win at Rock Paper Scissors
Rock paper scissors seems like pure luck, but when people play, habits and psychology mix in. There is no guaranteed win, but you can nudge the odds your way.
People are not truly random
When people throw by hand, patterns appear. Players who just lost tend to switch, and players who just won tend to repeat. There is also an observation that many people open with rock.
So if your opponent is human, they are not truly random, and reading those habits can give you a small edge.
Ways to gain a small edge
If your opponent just lost, they are more likely to switch next, so you can predict against what they just threw. It is only a tendency, though, so it will not always hold.
To avoid being read yourself, you need to be random. Since people are bad at randomness, deciding your throws ahead of time or using a truly random tool prevents prediction.
If you just want it fair
To decide purely by luck with no mind games, play against a random tool instead of a person. The computer has no habits, so it is perfectly fair. Play several rounds and track wins, draws, and losses to see the running result.
FAQ
What is the best opening move?
Since some people open with rock, paper can give a slight edge, but it is only a tendency and not guaranteed.
How do I make it completely fair?
Remove human habit by playing against a random tool, or decide your throw order at random in advance.