Players & Strategies

Configuring the decision-makers and their available actions.

Players

Basic Declaration

players Alice, Bob

Meaningful Names

Use names that reflect the domain:

// Economic games
players Firm1, Firm2
players Buyer, Seller
players Incumbent, Entrant

// Political games
players Congress, President
players Country1, Country2

// Social games
players Driver1, Driver2
players Hunter1, Hunter2

Strategies

Basic Declaration

strategies Cooperate, Defect

Multiple Strategies

strategies Rock, Paper, Scissors
strategies Low, Medium, High
strategies Enter, Exit, Wait

Shared Strategy Sets

Currently, all players share the same strategy set. This works for symmetric games like:

• Prisoner's Dilemma
• Stag Hunt
• Rock-Paper-Scissors

Modeling Asymmetric Games

For games where players have different actions, include all strategies and assign payoff 0 to invalid combinations:

game EntryDeterrence {
    players Entrant, Incumbent
    strategies Enter, StayOut, Fight, Accommodate
    
    // Entrant only uses: Enter, StayOut
    // Incumbent only uses: Fight, Accommodate
    
    payoff Entrant {
        (Enter, Accommodate): 2    // Valid
        (Enter, Fight): -1         // Valid
        (StayOut, Accommodate): 0  // Valid (no entry = no payoff)
        (StayOut, Fight): 0        // Valid
        // Entrant doesn't use Fight or Accommodate
    }
    
    payoff Incumbent {
        (Enter, Accommodate): 1    // Valid
        (Enter, Fight): -1         // Valid
        (StayOut, Accommodate): 2  // Valid (monopoly maintained)
        (StayOut, Fight): 2        // Valid
    }
}

N-Player Games

Games with more than 2 players are partially supported:

players P1, P2, P3
strategies Left, Right

However, payoff rules currently only support 2-strategy profiles. Full N-player syntax is coming in a future release.

Next Steps

• Payoff Matrices → — Complex payoff expressions