IteratedRockPaperScissors Environment Documentation

Overview

IteratedRockPaperScissors is a simple yet strategic two-player game environment based on the classic Rock-Paper-Scissors. Unlike the single-round version, this implementation runs for a fixed number of rounds (default: 5), and players try to win as many rounds as possible. The environment includes support for shorthand inputs and keeps track of full match history and scores.

Action Space

• Format: Players must submit their move using square brackets:

  [rock], [paper], [scissors]
  

  • Shorthand: [r], [p], or [s] are also accepted.
• Examples:
  • [rock], [r] — play Rock
  • [paper], [p] — play Paper
  • [scissors], [s] — play Scissors
• Notes: The rest of the player’s message is ignored. Only the first valid token inside square brackets is parsed.

Observation Space

Reset Observations

When the game starts, each player receives a prompt like:

You are Player 0 in a 5-round Rock-Paper-Scissors game.
Your goal is to win as many rounds as possible.
In each round, respond with one of: [rock], [paper], or [scissors].
You may also use [r], [p], or [s] as shorthand.
This is round 1 of 5.

Step Observations

After each round is resolved, all players receive the full history so far:

Previous Rounds:
Round 1: P0 -> rock, P1 -> paper
Round result: Player 1 wins!

Gameplay

• Players: 2 (Player 0 and Player 1)
• Rounds: Default is 5 (can be adjusted via num_rounds argument)
• Objective: Win more rounds than your opponent by playing the right moves.

Key Rules

1. Valid Moves:

   • A move must be one of [rock], [paper], [scissors], or their shorthands [r], [p], [s].

2. Round Outcomes:

   • Rock beats Scissors
   • Scissors beats Paper
   • Paper beats Rock
   • Same move = Draw

3. Match End:

   • After all rounds are played, the player with more wins is declared the match winner.
   • If wins are equal, the match is a draw.

4. Invalid Moves:

   • Invalid input (e.g., [banana]) results in an invalid move penalty for the player.

Rewards

Env-id

Contact

For questions or issues with this environment, please reach out to guertlerlo@cfar.a-star.edu.sg.