Can you out-Vizzini your partner or friend in a Battle of Wits?

Try this interactive experiment, based on economics research, with your significant other, close friend, or coworker.
Then learn more about the game-theory principles it demonstrates.

In the film The Princess Bride, based on William Goldman's novel of the same name, the mysterious, swashbuckling Man in Black challenges the egomaniacal villain Vizzini to a Battle of Wits.

The Man in Black explains the rules: into one of two goblets, he has placed deadly poison. All Vizzini needs to do is choose a goblet to drink; the Man in Black will drink the other one, and then one of them will die.

Vizzini explains his decision-making process to his opponent.

"All I have to do," he announces with bravado, "is divine from what I know of you. Are you the sort of man who would put the poison into his own goblet, or his enemy's? Now, a clever man would put the poison into his own goblet, because he would know that only a great fool would reach for what he was given. I'm not a great fool, so I can clearly not choose the wine in front of you. But you must have known I was not a great fool. You would have counted on it! So I can clearly not choose the wine in front of me!"

Your own personal Battle of Wits

Below, you will have an opportunity to engage in a similar Battle of Wits with your partner or friend.

This particular battle is adapted from a 2012 study by two economics professors, and after the battle is over, you and your opponent will get to learn a little bit more about what the professors were studying and what conclusions they drew.

To begin, select an adversary. It could be your significant other, your close friend, or your coworker — but it should be someone whose methods of thinking and decision making you are at least somewhat familiar with.

Next, click on the "Begin the Battle of Wits" link below. You will be asked to answer a few questions — it should take you 1 to 3 minutes.

Then, you will be given a personalized URL to provide to your adversary. Pass along that link to your adversary and encourage them to fill out their answers to the questions it asks. (It should take them 1 to 3 minutes as well).

After your adversary submits their answers, they'll receive a new personalized URL that they can share with you. It will provide the results of the Battle of Wits along with more information about the game-theory principles it demonstrates.

Your first name:

Your adversary's first name:

We are: