Two lemonade stands on the same block keep matching each other's price cuts until neither makes a profit — that self-destructive spiral has a whole branch of mathematics behind it. In plain words, game theory lists each player's options and payoffs in a grid, then weighs every outcome by its probability and adds the results to get a strategy's expected value. The famous Nash equilibrium is the square where neither player gains by switching alone: both stands holding prices steady, each afraid the other will undercut first. Poker players, merger negotiators, and even biologists studying animal conflicts all think in these grids, because strategy is just arithmetic about other people's choices.

This calculator compares two strategies head to head on expected value. Type the first strategy's expected payoff into the Variable A box, say 500, and the second strategy's into the Variable B box, say 350. Read the advantage from the Result box: 150, meaning strategy one beats strategy two by $150 on average. Flip the entries to confirm the sign flips. Before trusting the verdict, make sure the payoffs you typed are already probability-weighted — game theory punishes wishful thinking harder than any opponent will.

With the pre-filled defaults — Variable A 10, Variable B 5 — the Game Theory Calculator returns Result 50.0000. Change any input and those results update instantly, so you can see exactly how each number you enter moves the answer.