Colourblind Casting: For Amber anyway. White Emma Stone was considered for the role and Indian Freida Pinto was the second choice. Korean-American Jamie Chung ended up with the part.
Deleted Scene: Almost 20 minutes worth on the special edition DVD. Extended fight sequences, the love scene, some more motivational speeches all cut, but almost always stated to make the movie better, more understandable, drill Zack's point home and generally make the film more mature and enjoyable. The love scene with the High Roller is also The Reveal, so look for that one.
Doing It for the Art: Seriously. The studio wanted the film post-converted to 3D, but Snyder refused. He's done 3D before, but he didn't film Sucker Punch for 3D, and he felt converting it would make an inferior film. What makes this especially odd is that he claimed not to know why he made such an odd film, saying That is basically my comment on the film as well. "Why are you making this movie? You need to make a movie more commercial. It shouldn't be so dark and weird." Which in an odd way drives home his point about the nature of the film. It's so personal and yet so universal it had to be made "For the art" of it.
Dyeing for Your Art: Emily Browning bleached her hair platinum blonde. The dye ended up frying her hair and she had to cut it short immediately after filming wrapped. Pixie style.
Executive Meddling: The test screening of the film included a mild love scene following Baby Doll getting knocked out by one of Blue's men while Sweet Pea escapes between Baby Doll and the High Roller in his suite that is initiated by Baby Doll when he offers her freedom while in reality she's getting lobotomized. The MPAA did not approve of it and wanted the scene cut down; Zack Snyder cut it down to the point that it looked like the High Roller was taking advantage of Baby Doll, and then ultimately cut the scene altogether because that wasn't the message he wanted to give. However, the full uncut scene will be featured in the Director's Cut. In the original ending (that will not be included in the Director's Cut), when the police shines his light on Baby Doll post-lobotomy, she starts singing "O-o-h Child," followed by the rest of the girls appearing, and they all sing it on stage before the curtains fall.
Fake American: Emily Browning ("Baby Doll") and Abbie Cornish ("Sweet Pea") are both Aussies. Oscar Isaac ("Blue"), although born in Guatemala, doesn't really count as he was raised in Florida.
Shown Their Work: In this fantasy movie you will see better, more tactical use of firearms than in any Syfy Channel original movie about or including the military. Heck, it's also better than about 50% of other movies about the military (drops to 30% after 1985). The girls keep their rifles on their shoulders, roll in their steps rather than bouncing, and never cross lines of fire when clearing a room (and clearing the room they went from cover to cover, interlocking fields of fire). The firearms savvy troper will recognize EoTech holographic sites, historically accurate firearms (even the Samurai's 20mm version minigun), and a suppressed M4. Even handling a semi-automatic firearm, Baby Doll only crosses her thumbs in back once, but with hands that tiny it's believable she didn't catch the Colt Hammer Bite (when the slide comes back in the cycling of the action and cleaves any flesh in its way).
During the end credits, it's revealed that extensive musical and dance numbers were filmed but deleted for the theatrical release. The dance numbers are to be included on the DVD.
In the WWI fight scene, originally there were supposed to be zombie dogs alongside the soldiers.
Behind-the-scenes videos and various trailers show that the girls originally were shown battling through the castle courtyard, including Sweet Pea actually using the sword on her back, but the final film skips over this, instead skipping straight to the girls entering the castle.