Game Theory Lab vs DecisionPlay

"If the other side is exactly as clever as you are, what do you do?" Game Theory Lab lets you experience strategic decision-making by playing against an AI. Arguments that never quite land when you only read them start to make sense once you have made the choice yourself. [How each theme works] 1. Predict — commit to what you would do, and to what you think will happen 2. Play the AI — make your moves and watch the mind-reading play out 3. Read the explanation — see why it turned out that way, with charts and numbers Being wrong is the most interesting part. [Themes included (four are free)] Prisoner's Dilemma If you both betray, you both lose. Ten rounds against the AI show you why people betray anyway. Rock-Paper-Scissors Lab Can you really play at random? The AI is reading your habits. Ultimatum Game Split 1,000 yen. How much do you have to offer before the other side accepts — and when does a "profitable" offer get rejected? Tragedy of the Commons Everyone takes too much and the fish run out. Where is the sustainable catch? [Full Access Pack (one-time purchase)] One purchase permanently unlocks the remaining twelve themes. No further charges. Dictator Game How much do people share when nobody is watching? Tit for Tat Why does the "nice" strategy survive in a world full of defectors? Watch it play out over generations. Chicken Swerve first and you lose. Nobody swerves and it is a disaster. How do you make "I will not swerve" believable? Stag Hunt Cooperate and the prize is large — but can you trust the other side? Safety versus the bigger payoff. Matching Pennies Get read and you lose. Behaving genuinely at random is harder than it looks. Public Goods Game Everyone contributing makes everyone better off, and yet contributions collapse. Keynesian Beauty Contest Pick what everyone else will pick. How many levels deep does the second-guessing go? Winner's Curse You won the auction — so why are you worse off? Winning itself is bad news. Inspection Game What fraction of spot checks is enough to deter? The value of being unpredictable. Vickrey Auction When the winner pays the second-highest bid, bidding honestly becomes your best move. Dollar Auction Why does an auction for a 1,000-yen note end above 2,000 yen? Braess's Paradox Add one more road and everybody's travel time goes up. [Who it is for] - Anyone curious about economics, psychology, or decision-making - Anyone who wants the "why" behind negotiation and bluffing - Fans of brain training and popular-science content - Enjoyable from middle school age upward [Languages] Japanese, English, Korean, Chinese (Simplified), Russian, German, French, Spanish, Hindi

Game theory made easy. DecisionPlay turns everyday conflicts into strategy puzzles. Every situation, from splitting a dinner bill to a holdout negotiation, hides a game with rules. Name the game, see what each side wants, and find the move that changes the outcome. PLAY THE DAILY PUZZLE A new situation every day. Guess which game is hiding inside it in three tries, then read the full breakdown. Keep your streak going and share your result without spoilers. SCENARIOS TO PLAY Dating, family, work, negotiation, history, policy and more. Make the calls, then see how a game theorist reads the same moments. MAP YOUR OWN SITUATION Describe a real decision in plain words. DecisionPlay names the players, the options and the pressure points, and shows which assumptions drive the result. LEARN BY PLAYING Prisoner's Dilemma, Chicken, Stag Hunt, signaling and more, explained with plain language and interactive demos. Play bots that each follow one rule and beat them. NO ACCOUNT NEEDED Everything works without signing in. Your progress stays on your device. Move your streak to a new phone with a short code. Educational, not advice.