Every time Rock Paper Scissors comes up, I like to point out the superiority of Odds and Evens for resolving disputes.
Rules:
One player picks Odds, the other player picks Evens.
Someone says, "Odds, Evens, says, SHOOT", and both players put out either one finger or two fingers.
Count the fingers. If it's odd, Odds wins. If it's even, Evens wins.
Exactly 50% chance, no ties. RPS has always been obsolete.