Zoom Mod: Rock-Paper-Scissors

Rose Li
3 min readSep 17, 2020


Written for CS247G: Intro to Game Design (Fall 2020).

Rock-paper-scissors (RPS) is a classic. In a game of two players, both people secretly choose one of three plays: rock, paper, or scissors. Theoretically, each play has an equal probability of winning, and there is no optimal strategy to win the game.

I’d like to introduce a point system modification that creates an element of risk and reward, while preserving the lack of an optimal strategy. On the reward side, players can win a number of points depending on the play:

  • If a player wins with rock, player gets +3 points
  • If a player wins with scissors, player gets +2 points
  • If a player wins with paper, player gets +1 point

On the flip side, each play also comes with the risk of losing points:

  • If a player loses with rock, player gets -3 points
  • If a player loses with scissors, player gets -2 points
  • If a player loses with paper, player gets -1 point

Sometimes you gotta risk it for the biscuit. First player to 5 points wins.

Another critical aspect of the game is that both players must reveal their choice at the same time in order for a win to be considered “fair.” However, slow download speeds and video lags create a significant challenge when playing RPS over Zoom. So, I also wanted to replace the traditional method of using hand gestures with Zoom’s built-in functionality for reaction symbols:

  • Rock = “yes” (green check mark symbol)
  • Scissors = “no” (red “x” symbol)
  • Paper = “go slower” (grey “<<” symbol)

Since clicking a react button is quick and simple, this reduces the likelihood that players will accidentally (or intentionally 😳) reveal their choice after the other. Also note that the order in which these symbols appear on the Zoom interface is in decreasing point order (rock/“yes” → scissors/“no” → paper /“go slower”), so that it’s easy to pick the play based on how risky you’re feeling.

However, when playtesting this game in class, I realized a significant drawback of replacing RPS’ traditional symbols with Zoom’s reaction symbols. Even though it might be quick and easy for players to pick which button to click, it creates a new pain point: it becomes noticeably more inconvenient to discern which player actually won.

In the screenshot above, Jung-Won won the round with a paper-rock combo, resulting in +1 point for him and -3 points for Shane. However, none of us — admittedly, not even myself — were able to immediately recognize this since we had to first convert from “green check mark” to “rock” and “go slower” to “paper.” Unfortunately, this detracts from the game experience. In hindsight, perhaps it would have been better to use virtual backgrounds (one for rock, one for paper, one for scissors) and have each player turn off their video until it was time for both to reveal.

In addition, I realized that instead of making each player mentally keep track of their cumulative score, it would have been better to use tallies with Zoom’s whiteboard feature, or even share screen an Excel sheet.

Ultimately, it was a good learning experience, and I had a great time playtesting my first basic Zoom game!



Rose Li

stanford econ and hci