Lots of kids learn Rock Paper Scissors as their very first game of possibility and guidelines

https://rps-gambling-t-a-m-o7-140.rivetgarden.com/posts/why-no-one-cares-about-rock-paper-scissors-gambling-game

Many kids discover Rock Paper Scissors as their first game of possibility and rules. It teaches fairness, turn-taking, and how outcomes depend upon choices.