Built-in Games

Every game listed below has a built-in scenario you can run immediately with policy-arena run --example <name>. Use policy-arena examples to see all available scenarios.

All built-in games are also playable interactively at policyarena.dev.

Pairwise (Round-Robin)

Agents play every other agent each round in a round-robin tournament.

Game	ID	Description
Prisoner's Dilemma	prisoners_dilemma	Classic cooperation vs defection dilemma
Stag Hunt	stag_hunt	Risky cooperation (stag) vs safe defection (hare)
Hawk-Dove	hawk_dove	Aggression vs sharing over a resource
Chicken	chicken	Anti-coordination — swerve or crash
Battle of the Sexes	battle_of_sexes	Coordination with conflicting preferences
Trust Game	trust_game	Sender sends money (multiplied), receiver returns a share
Ultimatum	ultimatum	Proposer offers a split, responder accepts or rejects

N-Player (Collective)

All agents participate simultaneously in each round.

Game	ID	Description
Public Goods	public_goods	Contribute to a shared pool, multiplied and split equally
Cournot Oligopoly	cournot	Firms choose production quantities; market price falls with total output
El Farol Bar	el_farol	Attend only if crowd is below threshold
Tragedy of the Commons	commons	Extract from a shared renewable resource
Minority Game	minority_game	Choose between two options — minority wins
Voting & Election	voting	N voters elect candidates under plurality, approval, or Borda rules
Sealed-Bid Auction	auction	First-price or second-price (Vickrey) sealed-bid auction with private values
Information Cascade	info_cascade	Sequential binary decisions with private signals — herding dynamics
Lobbying Contest	lobbying	Tullock rent-seeking contest — spend to win a prize, highest spender most likely wins

Spatial / Network

Agents interact based on spatial proximity or network topology.

Game	ID	Description
Schelling Segregation	schelling	Agents on a grid relocate based on neighbor similarity
SIR Epidemic	sir	Disease spread on network with strategic isolation
Network Formation	network_formation	Agents form links; payoffs depend on network position and link costs

Agent Paradigm Support

Category	Rule-based	RL	LLM
Pairwise	yes	yes	yes
N-Player	yes	yes	yes
Spatial / Network	yes	yes	—

Inspecting a Game

# Show all strategies available for a game
policy-arena info prisoners_dilemma

import policy_arena as pa

reg = pa.get_registry().get("prisoners_dilemma")
print(sorted(reg.brain_factories.keys()))
# ['always_cooperate', 'always_defect', 'bandit', 'best_response',
#  'llm', 'pavlov', 'q_learning', 'random', 'tit_for_tat']