Share this

Wizard Recommends

Last Updated: July 14, 2010

Rock Paper Scissors


Rock Paper Scissors is a game found at Internet casinos using Playtech and Evoplay software. The image you see on top of this page is from the Playtech version.

Playtech Rules

The player chooses rock, paper, or scissors, and the computer will do the same. Rock beats scissors, scissors beats paper, and paper beats rock. If both throw the same thing the bet is a draw for single throw bets. The player may also bet on 2, 3, or 4 game series, in which he must win every throw (ties lose) to win the bet.

The single throw bets pay 1.9 on a win. The expected return is (1/3)*1.9 + (1/3)*1 = 2.9/3 = 96.67%.

A two throw series pays 8.7. The probability of winning is (1/3)2 = 1/9. The expected return is (1/9)*8.7 = 96.67%.

A three throw series pays 26. The probability of winning is (1/3)3 = 1/27. The expected return is (1/27)*26 = 96.30%.

A four throw series pays 78. The probability of winning is (1/3)4 = 1/81. The expected return is (1/81)*78 = 96.30%.

In the Playtech game the odds are the same for all three throws.

Evoplay Rules

Rock paper scissors evoplay

The Evoplay Entertainment version, called Rock Paper Scissors -- Viking Version, just goes one game at a time. Wins pay 1.92 for 1. the following table shows the expected return is 97.33%, counting ties as a resolved bet. We all know Rock Paper Scissors never ends on a tie, so if you don't count them, the return drops to 96%.

Evoplay Rules

Event Pays Combinations Probability Return
Win 1.92 1 0.333333 0.640000
Tie 1 1 0.333333 0.333333
Loss 0 1 0.333333 0.000000
Total 3 1.000000 0.973333

Real Life Strategy

When playing a novice human opponent, especially a male, always throw paper the first time! This is because most people tend to prefer rock, especially on the first throw.

Written by: Michael Shackleford

Wizard Recommends