Remember that age-restricted teaser trailer for Tropic Thunder that debuted online in March? Funny, right?

That was nothing compared to the R-rated trailer just released for the upcoming comedy starring Ben Stiller, Jack Black, and Robert Downey, Jr.

We knew from the beginning that the story centered around a group of prima donna actors making a big-budget war movie. The new age-restricted trailer finally shows us some background on the actors and what makes them so high maintenance. And, it features a lot of Downey’s movie-within-a-movie character, a serious Australian white actor who undergoes a procedure to turn his skin black in order to play an American black character in the war movie.

The Ben Stiller-directed film also stars Nick Nolte, Bill Hader, Jay Baruchel, Brandon T. Jackson, and Steve Coogan.

Tropic Thunder hits theaters on August 15, 2008.