With many hundreds of people pooling their talents in order to get a movie made, virtually no film shoot goes 100% according to plan. Scenes often have to be re-shot months later, or if filmmakers are lucky, they just might catch their own mistake before the cameras start rolling.
We all know how drastically a film can change due to reshoots and other design modifications - just look at the film-saving Sonic the Hedgehog re-design last year - but sometimes the alterations are a little more subtle than that.
This is especially true where characters are concerned, because while it's enormously costly and time-consuming to entirely reinvent every aspect of a character from the ground-up - or, God forbid, recast - smart filmmakers can subtly iterate on their more minor attributes.
From the sound of their voice to their hairstyle, eye colour, the subtle disposition of their character, and perhaps even their name, these 10 characters were all given sly, slight touch-ups during production, and in some cases, just a short time before the film finally landed in front of audiences...
10. Apocalypse's Voice Was Redubbed & Remixed To Sound More Menacing - X-Men: Apocalypse
It's fair to say that most X-Men fans were left underwhelmed by Oscar Isaac's portrayal of Apocalypse - and Isaac himself wasn't exactly thrilled with how it turned out - in large part because of the character's unimposing design.
Many fans lamented the fact that the cinematic En Sabah Nur simply didn't look as supernaturally large as his comic book counterpart, basically resembling, well, a guy in a suit.
This was compounded by some complaining that, in the first teaser trailer, Apocalypse's voice didn't sound nearly badass enough for a planet-annihilating Big Bad. He pretty much just sounded like Oscar Isaac shouting.
The feedback soon enough got back to director Bryan Singer, and mere weeks before the film opened, he informed fans that Apocalypse's voice was still being finalised.
Though the villain's voice did improve between trailers as the film's release neared, the more distinctively different, bass-rich vocal tenor that appeared in the end product was the result of Isaac's vocals being re-recorded with three microphones simultaneously during post-production.
This allowed the sound mixing team to combine the three recordings to create a more uncanny voice. Apocalypse still sucked, but at least he sounded a little less like a human playing dress-up. In Singer's own words:
"It ebbs and flows and moves through the movie, and changes, so he doesn't just have one single voice. He speaks with different voices depending on different moments in the film. So it's really kind of cool. It's the first time I've ever had the tools to sculpt a performance in post-production, that was already given to me on set and chosen in the cutting room."