Game theoryClassroom · multi-user
Public Goods Game — Save the Commons
A class-wide cooperation game: each round, contribute to a shared Climate Fund and watch how free-riding emerges.
You’ll learn: Understand why shared goods get under-funded and how individual incentives drive free-riding.
- Public goods
- Free-riding
- Externalities
- Collective action
Teacher guide
Students will learn to
- See why a shared resource everyone benefits from tends to be under-funded.
- Feel the tension between the group's best outcome and each person's private incentive.
- Recognize free-riding and why cooperation often erodes over repeated rounds.
Before the session — ask
- If everyone chips in, the whole group is better off — so why might someone hold back?
- Where in real life do we rely on people voluntarily contributing to a shared good?
After the session — discuss
- Did average contributions rise, hold steady, or fall over the rounds? Why?
- What was the gap between what the class earned and the best possible group outcome?
- What rules or norms might keep people contributing — taxes, reputation, punishment?
Timing
- Briefing & the rules3–5 min
- Eight contribution rounds8–12 min
- Debrief & discussion8–10 min
Run it with your class
Students join with a code or QR — no account needed. Teachers start a session from the dashboard.