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Thank God You People Don’t Have The Nuclear Codes

Let’s all be thankful that FiveThirtyEight readers don’t control America’s nuclear arsenal.

Last week, we published an article on the game theory of nuclear standoffs. That article included an interactive game meant to let readers pretend they were themselves participants in a showdown in which something could be gained, and much more could be lost. The rules were simple:

Imagine that a crisp $100 bill lies on a table between us. We both want it, of course, but there’s no chance of splitting it — our wallets are empty. So we vie for it according to a few simple rules. We’ll each write down a secret number — between 0 and 100 — and stick that number in an envelope. When we’re both done, we’ll open the envelopes. Whichever of us wrote down the higher number pockets the $100. But here’s the catch: There’s a percentage chance that we’ll each have to burn $10,000 of our own money, and that chance is equal to the lower of the two numbers.

So, for example, if you wrote down 10 and I wrote down 20, I’d win the $100 … but then we’d both run a 10 percent risk of losing $10,000. This is a competition in which, no matter what, we both end up paying a price — the risk of disaster.

In the real world, the $100 is analogous to some international concession and the $10,000 is the high cost of all-out nuclear war. The two players are bidding for the “$100” in the currency of nuclear risk.

As of Wednesday afternoon, FiveThirtyEight readers had played this game nearly 200,000 times and the results are in. They are calamitous. The median submission was 33, the mean was 43 and the most common entry was 100 — in other words, uncompromising aggression. Disaster occurred over 20 percent of the time and nearly $2,000 was destroyed, on average, per game.

This game was make believe, of course. None of our readers, hopefully, burned $10,000 of their real money. And readers’ fingers, presumably, weren’t hovering over the nuclear launch button. (President Trump, if you’re reading, holler.)

“This is a common problem when trying to do illustrative games in classes. The mental frame people usually bring is that it is a ‘game,’ and so just like other games (poker, football, etc.), the point is to win,” James Fearon, a political scientist who teaches this game to his Stanford students, said. “So people often play very aggressively, probably much more than they would if they actually had $10,000 of their own money at stake.”

We can only hope our world’s leaders have taken a proper accounting of the stakes.

Oliver Roeder was a senior writer for FiveThirtyEight. He holds a Ph.D. in economics from the University of Texas at Austin, where he studied game theory and political competition.

Julia Wolfe is FiveThirtyEight’s former senior editor, data visualization.