In Japan, paper-rock-scissors (or paper-scissors-stone, depending on where you're from) is known as jan-ken-pon. While this simple game may not be all that big a deal in your home country, in Japan, children use it to decide virtually everything. And this means that if you plan on teaching at schools in Japan, janken is one of the very first skills you need to pick up, since it's the easy way to split a group or decide who talks first in an activity.

Above, our very own Japan Guy explains the ins and outs of janken, including several variations on what to say, what to do in the event of a tie, and how to play the "acchi-muite-hoi" after-game.

Then there's the super-advanced, song-based version. Just don't go teaching kids the trash-talk retort at the end!