noun, noun or participle which takes 'suru', intransitive verb
rock-paper-scissors; janken
The hand game played by two or more people, often to decide something. Can also be used as a verb with する (じゃんけんする).
じゃんけんで勝った人が先に選べるよ。
The person who wins at rock-paper-scissors gets to choose first.
どっちがやるか、
Let's decide who does it by playing rock-paper-scissors.