In Man of Steel, Superman goes commando. Sort of. While he still has that red cape and the "S" on his chest, he's missing those little red briefs. What gives? The underwear wasn't "consistent with the world we were creating," according to director Zack Snyder.
Snyder and other members of the Man of Steel team explain this peculiarity in an extended featurette (one that builds on the discussion, centering on how "real" the film is, from last week). Just like everything else in this movie apparently, the suit cannot be left up to fantasy. Snyder's co-producer and wife Deborah says that it was important to her husband for the suit "to make sense." So Superman's new suit—sans the loincloths of Kal-Els past—is a "commonplace" get-up on Superman's home planet of Krypton.
Sure, Snyder looked at a bunch of versions of the suit with underwear, but he just couldn't make it work. As for the briefs, well, they were just too old fashioned, being a "leftover from Victorian-era strongmen." No, this Superman suit is all too modern. It's also apparently all Henry Cavill when it comes to muscle definition, according to another actor, if you were wondering.
Clearly, Snyder is hoping that by doing away with the more kitschy elements of Superman's persona, he can create a franchise with legs. He recently told Collider that he thinks there needs to be more Superman if there's going to be a Justice League movie.
You can watch the full featurette below, which also features the cast and crew's various takes on characters like Lois Lane and Perry White.