Watch Jennifer Lawrence, John Oliver Play True Confessions With Jimmy Fallon

'X-Men' star reveals a time she accidentally took a sleeping pill before filming a scene for 'The Hunger Games'

While stopping by to promote 'X-Men,' Jennifer Lawrence played True Confessions with Jimmy Fallon and John Oliver on 'The Tonight Show.'

Jennifer Lawrence, John Oliver and Jimmy Fallon tested their acting skills with a game of True Confessions on The Tonight Show. Lawrence stopped by the late-night show to promote the latest X-Men film.

For the game, each person has two envelopes. One envelope contains a true fact about them and the other contains a lie, but no matter which one they randomly open, they have to convince the other two contestants that it is a true fact. Lawrence was up first, and her envelope revealed that she had taken Ambien before filming a scene in The Hunger Games, which turned out to be a fact. Fallon revealed that he offered a song he had written called "Am I Doing It Wrong?" for Paul McCartney, another fact.

"I figured nobody sends song ideas to Paul McCartney," Fallon explained. "He's the greatest songwriter on the face of the earth."

After a brief moment for Lawrence to clear a booger from her nose, Oliver came up next and attempted to convince the other two that he had worked in the kitchen at Buckingham Palace one summer as a kid, but his lie was caught and quickly revealed. 

Find out five things you didn't know about John Oliver.