Don Eppes is an FBI agent of the all I need to know I learned on the streets ilk. His brother, Charlie, is a brilliant, reclusive university professor brother. Charlie helps solve crimes by relating the crime to seemingly complicated (though generally nonsensical) mathematical theories. Two episodes of Numb3rs involved game theoretic themes directly.

"Assasin" (Season 2, Episode 5)

Charlie and Don are in pursuit of an assassin, attempting to calculate where the killer would strike.

Charlie: Hide and seek.
Don: What are you talking about, like the kids' version?
Charlie: A mathematical approach to it, yes. See, the assassin must hide in order to accomplish his goal, we must seek and find the assassin before he achieves that goal.
Megan: Ah, behavioral game theory, yeah, we studied this at Quantico.
Charlie: I doubt you studied it the way that Rubenstein, Taversky and Heller studied two person constant sum hide and seek with unique mixed strategy equilibria.
[[Editor's note: the original series script misspelled the names of Rubinstein, Tversky and Heller ]]
Megan: No, not quite that way.
Don: Just bear with him.

And bear with him we do. The best part is:

Don: How long will it take you to come up with some probabilities?
Charlie: Soon

A bit later we have:
Don: So, does that make me a three-step thinker?
Charlie: You keep working with me, you'll get there soon enough.
Don: Shut up.

"All's Fair" (Season 2, Episode 18)

Don seeks the murderer or an Iraqi woman in pursuit of women's rights. Of course, everything is somehow connected to Saddam Hussein. There are loose connections in the episode to the games developed by Harsanyi.

Mike Shor, 2006