The traditional game of Rock Paper Scissors can be adapted in a way that allows you to always predict the outcome. The adapted game goes as follows:

1) Between 3 players, each person must pick one out of Rock, Paper, or Scissors. As standard, players can’t have the same item.

2) Now tell your friends “2 of you must switch items. Since I already know exactly what switch will be made, I’ll write down the results”. Note down that “Player-who-picked-Scissors will beat Player-who-picked-Rock” (using their real names).

3) Allow your players to make any switch of their choice.

4) Reveal your note, predicting the results.

This game is extremely simple. No matter what switch is made, the player who originally selected Scissors will always beat the player who originally selected Rock.

Senario 1: Rock and Paper switch

The player with Rock will now have Paper. The player with scissors will still have scissors. The player with scissors will beat the Player who initially picked Rock, who now has Paper. Your prediction stands true.

Senario 2: Rock and Scissors switch

The player with Scissors will now have Rock and vice versa. The player with Rock, who initially picked Scissors, will beat the Player who initially picked Rock, who now has Scissors. Your prediction stands true.

Senario 3: Scissors and Paper switch

The player with Scissors will now have Paper. The player with Rock will still have Rock. The player with Paper, who initially picked Scissors, will beat the Player who still has Rock. Your prediction stands true.

This stunt comes from the show Penn & Teller Fool Us, performed by Hans Petter Secker. You can watch a live demonstration of this trick here: https://www.youtube.com/watch?v=hf7Sy7FPal0