A trainer, not a textbook
The Game Theory
of Everything
see the game you are already in
Wherever outcomes are interdependent, you are in a strategic situation with a recognisable structure. There are roughly twenty such structures in ordinary use, and almost every conflict, negotiation, stalemate and institution you will meet is one of them wearing local clothes.
Read it your way
Every explanation on this site exists three times.
Press one and watch the sentence below change. Nothing is left out of the plain version — it is translated, not simplified, and it is often the sharpest of the three, because you cannot hide a fuzzy idea behind a technical term. Your choice is remembered on every page.
Working — The words people actually use at work and in the news.
The same idea, at the level you chose
An equilibrium is a stable point: no single player gains by unilaterally changing strategy. It does not mean fair and it does not mean efficient — only that no one can improve on their own.
If you would rather be told
Two minutes, out loud.
The whole claim
Spot every player at the table.
Most applied errors are player-set errors, not solution errors. The list nearly always contains the people in the meeting and omits the enforcer, the observer, the implementer and the party the decision is actually about. Each omission removes a constraint that was doing real work, which is why the analysis then fails to predict what happens.
That is what this site trains. Not the maths — the seeing. Given a real situation, can you name everybody whose choice matters, say what shape it is, predict where it lands if nobody changes anything, and identify the one move that would actually change it?
Four ways in
Wherever you want to start.
Train the eye
Real-shaped situations across every domain. Spot the players, name the shape, predict the outcome, find the move. Four beats, scored, with the reasoning shown for every answer including the wrong ones.
The shapes · 20Learn the twenty
Every one with how it feels from inside, who usually gets left off the player list, where it lands, what moves it — and the near neighbour people mistake it for, with the one question that tells them apart.
Everything · 16 domainsLaw to dating
The same twenty shapes turning up in courts, feeds, newsrooms, markets, parliaments, offices, kitchens, clinics, schools, borders, platforms, policing, sport, the climate, congregations and first dates.
Field guide · 12 ideasExplained in full
The whole working vocabulary, written three times over. Player, strategy, payoff, incentive, information, equilibrium, dominance, credibility, repetition, signalling, mixing — and what each one is for.
One warning
This is not a manipulation manual.
The word game is unfortunate. It suggests either entertainment or trickery, and it means neither. Most of the shapes in here have no villain in them at all, and the ones that hurt the most usually have nobody to blame — which is exactly why they are so hard to fix by finding someone at fault.
What this actually gives you is more ordinary and more useful: situations stop looking like other people being unreasonable and start looking like arrangements that could be changed. You spend less time asking who is to blame and more asking what would let somebody move.