Strategy Arena — Program‑Your‑Bot (Iterated Prisoner’s Dilemma)

Code your move rule, then run a round‑robin vs classic bots. Learn Nash, reciprocity & exploitation by watching the outcomes.
Your Strategy (returns 'C' or 'D')
Strategy API (safe subset)
Your function is called every round with an api object. Return 'C' or 'D'. 
function move(api){
  // Read-only helpers
  api.round        // 1-based round index
  api.history      // [{me:'C'|'D', opp:'C'|'D', pa:number, pb:number}, ...]
  api.last()       // last round object or null
  api.oppLast()    // 'C'|'D' or null
  api.meScore()    // my cumulative payoff so far
  api.oppScore()   // opponent cumulative payoff
  api.rand()       // deterministic RNG in [0,1)
  // Return 'C' or 'D'
  return 'C'
}
Security note: code runs in a tight sandboxed Function; no DOM/window access. Timeouts are guarded.
Payoffs & Results
Prisoner’s Dilemma Payoff Matrix [You, Opp]
C,C → 3,3
C,D → 0,5
D,C → 5,0
D,D → 1,1
Equilibrium: D,D. Long‑run cooperation can dominate vs reciprocators.
Coach
Write your rule, then hit “Run Tournament”.

Tournament Table

Average payoff per round (higher is better). Green = beats opponent; red = loses.

Match Log