Two drivers race towards each other down the middle of a narrow road. Whoever swerves first is the chicken.
If both swerve, nobody wins and nobody is hurt. If one holds on while the other swerves, the one who held on wins. If neither swerves, they crash.
Winning is worth 1. Both swerving is 0. Swerving while the other drives on is minus 1. A crash is minus 10.
You are Driver A
Watch one round, or choose now.
Driver A
or
You
Driver A
?
You
Driver B
or
The other driver
Driver B
?
The other driver
The other driver picks at random here, like a coin toss.
The whole game on one grid
Every pair of choices and what each side gets: yours first, then theirs. Each number is a payoff.
Step 0 of 3
The cards are face down. Turn them, then step through which squares are stable.
What do you think they'll do?
Your best move depends on what you expect from the other driver. Drag to set how likely you think it is they pick Swerve.
What it teaches
Both equilibria need someone to give way, so the fight is over who is believed to be unable to.
The usual mistakeTreating it as a test of nerve and hunting for the strategy a brave player would take, when the equilibria are defined by who gives way and bravery on both sides produces the outcome both rank last.
The checkCheck whether either player has a move that is better regardless of the other. Neither does, so the question is not how bold you are but what the other side believes you can no longer choose.
In the real world
Fiction: Rebel Without a Cause
The chickie run
Two teenagers race stolen cars towards a cliff, and whoever leaves his car first is the coward. Jim jumps and gets clear. Buzz's sleeve catches on the door handle so that he cannot get out, and he goes over the edge with the car.
Both equilibria require one of them to give way, and what is actually being competed over is the appearance of being unable to, which the film then makes literal: the player who genuinely loses the ability to swerve wins the contest and is killed by winning it.
Real worldContested
The 2023 debt ceiling standoff
In the first half of 2023 the United States reached its statutory borrowing limit, with the House majority refusing to raise it without spending restraint and the administration insisting on an increase with nothing attached. Both sides spent months saying publicly that they would not move, while nearly everyone described default as the worst available outcome for both of them, and a deal was reached only days before the Treasury's estimated deadline, passing as the Fiscal Responsibility Act in June 2023. The 2011 standoff had run the same way and ended in a downgrade of the federal credit rating, which is the closest thing to a collision the sequence has produced.
Each side's best outcome is the other giving way, and the outcome where neither gives way is far worse for both than giving way would have been, so the contest is over who can be believed to be unable to move: hence the public pre-commitments, the hostile caucus a Speaker can point to, and the refusal to name a fallback. That is chicken and not a coordination game, because the two equilibria each require a different player to yield. The inference is that the House leadership was optimising for the survival of its own position with its members rather than for the fiscal outcome, and which side actually swerved is still argued over, as the model would predict.
Nash demand gameThe demands are a continuum rather than two actions, so the question is not who gives way but how much, and every division is an answer. Not on the wall yet.
Volunteer's dilemmaThere are n players rather than two, so the question is not who gives way but whether anybody does, and the answer gets worse as the crowd grows. Not on the wall yet.