Ultimatum Bargaining
How this teaches game theory
The ultimatum game separates purely monetary rationality from fairness-sensitive behavior. A responder can reject an unequal offer even though rejection gives both players zero, while a proposer anticipates that possibility when choosing a split.
Complete scenario, mode, level, and concept guide
Scenario explanations
Classic split
Divide 10 tokens. The proposer chooses the responder's share; acceptance implements the split, rejection gives both zero.
Scarce resource
Divide 6 tokens. Fewer feasible splits make each token more strategically important.
Repeated bargaining
Play repeated 10-token rounds and compare how offers evolve after acceptance or rejection.
Modes
Human proposer
You choose the offer; the computer decides whether to accept.
Human responder
The computer proposes; you accept or reject.
Human vs Human
Player 1 proposes and Player 2 responds on the same device.
Computer vs Computer
Automated bargaining reveals how different behavioral rules interact.
Levels
Level 1 — Lenient
Computer responders accept any positive offer; computer proposers make low but nonzero offers.
Level 2 — Strategic
Computer responders demand roughly 30%; proposers anticipate that threshold.
Level 3 — Fairness-aware
Acceptance thresholds move toward an even split, emphasizing fairness norms and rejection risk.