Rock Paper Scissors
Challenge the computer at the world's oldest game: tap your move and see who takes the round. The scoreboard keeps track of the whole match.
Can you actually beat your opponent? There is real strategy
In theory the perfect play is pure randomness: if each move shows up a third of the time, nobody can exploit you. In practice humans are terrible random number generators. Studies of tournament play show that winners tend to repeat their last move, while losers tend to switch to the move that would have beaten what they just played. Against a person, anticipating those patterns pays off. The computer on this page, however, picks truly at random: over the long run the match drifts toward a tie, and every round is pure suspense.
From jan-ken-pon to schoolyards everywhere
The game originated in China and spread through Japan as jan-ken-pon, where it is still used to settle just about anything, from office chores to sports tie-breakers. English speakers know it as rock paper scissors — or roshambo. The rules never change: rock crushes scissors, scissors cut paper, paper covers rock. Three moves, none dominant — that perfect balance is what makes it timeless.