This is the final exam for Game Theory: Thinking in Moves. It pulls together the whole course: the three ingredients of a game and the payoff matrix that holds them, dominant and dominated strategies, the best-response method and the Nash equilibrium, the prisoner’s dilemma and why rational players both lose, the way repetition and tit-for-tat rescue cooperation, and the wider map of trust (the stag hunt), nerve (chicken), and the zero-sum/positive-sum mindset. Take your time — several questions look obvious until you spot which game you’re really in.
How this exam works
Read carefully — this exam is final. Each question appears one at a time. Once you submit an answer it is locked for good: there’s no going back, no retry, and no restart. Your score is hidden until the end, where you’ll see a pass/fail verdict. The pass mark is 70%. A few questions ask you to select all correct answers.
What is the defining feature that makes a situation a "game" in the technical, game-theory sense?
Select an answer to continue.
Course Recap
Big picture
Game theory, in one picture
- Game Theory
- Write the game down
- Players, strategies, payoffs → the payoff matrix (row payoff first)
- Solve it
- Dominant strategy if you’re lucky; otherwise the Nash equilibrium (mutual best responses, stable not optimal)
- The prisoner's dilemma
- Defect is dominant → mutual defection, worse for both than cooperation. Engine of the commons, arms races, price wars
- Repetition rescues it
- Shadow of the future → tit-for-tat (nice, retaliatory, forgiving, clear) wins; a known last round unravels it
- Know which game you’re in
- Stag hunt = trust · chicken = nerve · zero-sum vs positive-sum (beware the fixed-pie fallacy)
- Write the game down
Key takeaways
Game theory is second-order thinking aimed at another strategist: when your payoff depends on someone else’s choice, write the situation as a payoff matrix, then solve it. Grab a dominant strategy if one exists; otherwise find the Nash equilibrium — the mutual-best-response cell that’s stable, not necessarily good. The prisoner’s dilemma is the painful case where defection is dominant and both rational players lose, the hidden engine under arms races, price wars and the tragedy of the commons — and you escape it not by moralising but by changing the game, above all through repetition, where tit-for-tat (nice, retaliatory, forgiving, clear) makes cooperation rational. But not every game is a dilemma: the stag hunt turns on trust, chicken on credible nerve, and the costliest error of all is the fixed-pie fallacy — fighting zero-sum over a pie you could have grown. Always diagnose the game before you choose your move.