In the overwhelming majority of movies, an actor will elect to play a single character, and that's quite understandably all you're going to get. It makes sense, right?
But acting being a profession of experimentation above all else, sometimes performers will decide to play multiple parts in the same film.
Yet to avoid needlessly confusing the audience, they might play at least one of those other characters underneath heaps of makeup.
It's not that uncommon for actors to play two roles in a film - particularly twins, for instance - but more adventurous actors might spring for three or even more.
These 10 actors all played three-or-more roles in these movies, typically donning feature-changing makeup to no longer resemble themselves and disappear entirely into these distinct individuals.
In some cases the transformation is so drastic that general audiences don't even spot every single role played by the actor, as proves a jaw-dropping, even hilarious surprise when they finally realise.
Some transformations are more persuasive than others, naturally, but these 10 actors all truly went above and beyond to vanish into these wildly diverse roles within the same movie.
10. Michael J. Fox - Back To The Future Part II
Back to the Future Part II has a lot of fun allowing Michael J. Fox and Thomas F. Wilson to play various iterations of Marty and Biff.
As such it's no secret that Fox ends up playing both young and old versions of Marty, and also Marty's son Marty Jr., though he additionally plays a third character you may not have noticed.
Fox is also concealed under copious amounts of makeup to play Marlene McFly, Marty's daughter, who appears briefly in the film.
It's an incredible enough job that you'd be forgiven for just assuming an actress resembling Fox was hired for the part, especially if you grew up watching the film.
As exceptional as the makeup is, though, it's Fox's soft facial features that really help sell the transformation into a frankly genuinely pretty teenage girl.
Because playing three characters in the same movie isn't enough, though, director Robert Zemeckis even has Fox play Marty, Marty Jr., and Marlene in the same scene at one point.