Emma Stone has a lot of wonderful qualities -- but her ability to lie isn't one of them. During last night's (Oct. 14) visit to 'The Tonight Show Starring Jimmy Fallon' the actress and comedian faced off in a game of Box of Lies.

The concept is simple: Each competitor is asked to describe the hidden contents of a box to the other person. The first person can lie or tell the truth about what's in the box, but it's up to the second person to determine the authenticity of the claims. (You might remember Jennifer Lawrence slaying her game of Box of Lies earlier this year.)

"I love to lip sync, but I am a terrible liar," Emma warned Jimmy before she selected her box.

But is she telling the truth ... or just bluffing? You'll have to watch the video above to find out! (Bonus: Check out Emma discussing her first musical in the video below!)

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