Rock Paper Scissors has been used to decide virtually everything: who pays for lunch, who sits in the middle seat, who makes the call nobody wants to make. Given enough time and enough shared context, people have applied it to romantic situations too. "Rock Paper Scissors Kiss" is the version where the winner earns a kiss as the stakes.
The logic is the same as any other RPS wager: both parties agree to the stakes before the game, play a clean simultaneous reveal, and the outcome determines what happens next. In the romantic version, the winner gets a kiss, or doesn't, depending on the agreement. It's a low-stakes way for two people who already like each other to create a moment with a guaranteed outcome in under ten seconds.
What makes it work in the right context is the same thing that makes RPS work as a general decision mechanism: both parties participated in the result. The game didn't pick the winner arbitrarily. Both players made a choice and one of them read the moment better, or got lucky, or both. That shared agency makes the outcome easier to accept than a coin flip.
What makes it fail in the wrong context is equally obvious: it only works if both parties actually want to play and genuinely agree to the stakes. A Rock Paper Scissors challenge for a kiss that one person didn't want to enter isn't romantic. It's uncomfortable. The game is neutral but the consent required around it is not. This is not a technicality. It's the whole thing.
For couples who already have established shorthand for small decisions, RPS as a low-stakes romantic mechanism fits naturally into the kind of daily playfulness that characterizes relationships that are actually working. It's a ten-second game that both people find funny and both people accept. That's a small signal but a real one.