In Japan the game is called jan-ken, you say "Jan-ken-pon!" when getting ready to throw, and the moves are guu (rock), choki (scissors), and paa (paper).
(FWIW, the *more* commonly used name in Germany is "Schere, Stein, Papier" (scissors, rock, paper). There's a *number* of alternative "names", however - which are said aloud when playing so as to "sync" the players.)
As a Swede, I would say it is rock, scissors, bag, not sack. A påse is much smaller than a sack. Not a handbag, mind, a grocery bag, or a pouch. Actually, I changed my mind, rock, scissors, pouch would work best, in my opinion. Not sack, though.
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