"Now, here's how it works. Upstage there are a bunch of boxes filled with objects we've never seen before," Fallon told the audience. "Once the object is out of the box, you tell your opponent what's in the box. You might be lying, you might be telling the truth. Your opponent needs to guess which one, either lie or truth. You guess correctly, you get a point. You guess wrong, the other person gets a point. First person to two points, wins."
Tatum, 34, who wore a Gucci Monaco suit and is currently promoting his new movie Foxcatcher, was first to go and removed a Chewbacca action figure wedged in a bowl of gelatin. "Do you know what's in my box?" he asked Fallon, who burst out into laughter.
The two then proceeded to go back and forth with their items until finally, Tatum unwrapped an E.T. doll snuggled inside a miniature sleeping bag with crowns.
Watch the actor tell the truth and find out whether Fallon believed him or not, above!