Rock Paper Scissors Variations
A variation can change actions, outcomes, or match format. Each change needs an explicit ruleset.
A Rock Paper Scissors variation may change the actions, the outcome graph, or the match format. In a symmetric odd-action system where every pair has one winner, each action can beat and lose to the same number of alternatives: (n−1)/2. If two players choose independently and uniformly, the tie probability is 1/n. Variants are not required to use that design, so their rules must be stated explicitly.
Rock Paper Scissors Lizard Spock
Sam Kass’s rules page credits Rock Paper Scissors Lizard Spock to Kass and Karen Bryla. It adds two actions to a symmetric five-action cycle. Under independent uniform choice, matching actions account for 5 of 25 ordered pairs, so the tie probability is 20%. See the full sourced RPSLS guide.
How It Works
- Scissors cuts Paper, decapitates Lizard
- Paper covers Rock, disproves Spock
- Rock crushes Lizard, crushes Scissors
- Lizard poisons Spock, eats Paper
- Spock smashes Scissors, vaporizes Rock
The five gestures represent a complete directed outcome table: every action beats two, loses to two, and ties with itself. Event records should identify this ruleset rather than treating it as classic RPS.
Historical Games Are More Than Reskinned RPS
Research on Japanese ken games documents older hand-game families, including mushi-ken and kitsune-ken. Their symbols and social settings matter to their history, and they should not be collapsed into a single modern “regional variant” list without explaining the evidence and the actual outcome rules.
Formats Built on a Ruleset
Simultaneous Team Format
A team format can ask every member to reveal simultaneously and use the team’s majority action, but the organizer must define what happens when no action has a majority. Results should be labeled as team-format records so they are not confused with individual classic matches.
Elimination Bracket Format
Pair players for a declared number of rounds, advance the winner, and repeat until one player remains. Organizers must define how ties, byes, seeding, disconnections, and disputed reveals are handled. This is a tournament format layered on a ruleset, not a new set of gestures.
The Mathematics Behind Variations
For a symmetric variant with an odd number n of actions, where every pair has one declared winner, each action can beat (n−1)/2 alternatives and lose to the same number. Under independent uniform choice, equal actions produce a tie with probability 1/n. These conclusions depend on those assumptions; they do not apply automatically to every game called an RPS variant.
| Variant | Elements | Each Beats | Tie Rate |
|---|---|---|---|
| Classic RPS | 3 | 1 | 33.3% |
| Lizard Spock | 5 | 2 | 20.0% |
WRPSA’s published rules and classic records use Rock, Paper, and Scissors. Any extended or format-specific dataset should store a ruleset identifier so comparisons do not combine different outcome graphs.
Choose a ruleset before play
Start with the published classic rules, or declare a complete variant ruleset before collecting results.