Cast as a Mask

So you want to make a mystery movie. When Alice finds out that the masked villain is actually her friend Bob, you want it to be a truly effective reveal. To that end, you've made an effort to avoid using a Paper-Thin Disguise... but you've hit a snag; a casting snag. Bob's actor is - in some way or another - distinct; too distinct. No matter how good the disguise is, the viewer is still very likely to guess the villain's identity early on. What do you do? Fire the actor and recast the part?

Not necessarily. You see, dear Troper, there is another way to avoid this pitfall. When an actor is either too famous, looks too distinct, sounds too distinct, or is some combination of all three; it's often a good idea to cast someone to be the mask; in other words, bring on a different actor to play the character whenever they are wearing their disguise.

This way (one can only hope) the audience won't guess the secret, at least not until you want them to.

Note that, although this is often done for villains, it is not limited to them. This trope can include any character, whether they are good or evil (or neither).

Can overlap with The Nth Doctor if the phenomenon is given an In-Story justification. Can also overlap with and even invert Samus Is a Girl, as some of the examples will demonstrate.

'''Warning: This page contains spoilers! Read at your own risk!'''

Anime

 * The Anime adaptation of Monster does this. To make the reveal that the pretty new girl in town is more shocking, the studio used  to play  whenever  dons this look. This is done both in the Japanese version and in the English dub.
 * In the English dub of Noein,
 * To be more specific, Karasu is an alternate future version of Yuu, the show's main protagonist.
 * The unnamed Shinigami in the first Death Note Relight special. The ending hints that
 * In Gurren Lagann, the narrator is revealed at the end to be, but in both English and Japanese they have different VAs...except in the epilogue, which is how it's revealed in the first place.
 * In Eden of the East, Akira is informed about the Selacao by Hajime Hiura, Selacao number 5, who recreates for Akira the circumstances of his recruitment by Mr. Outside. On the recording, Mr. Outside's voice is the same as that of Hiura. This makes some sense as the series raises the possibility that any of the Selacao could be Mr. Outside/"The Supporer" and not know it due to Laser-Guided Amnesia.
 * Naruto has a somewhat convoluted example: Pain has six bodies, and all but the female one speak with the voice one of them had when he was alive.
 * The Japanese version of Yu Yu Hakusho plays with this trope with the Masked Fighter. Judging by height and appearance, she is very obviously Genkai...but then she speaks with the voice of Megumi Hayashibara, causing confusion even before
 * Katsuhito Masaki, from Tenchi Muyo!, in all the various incarnations of the series, has his own voice actor, apart from his alter ego of Yosho.

Film (Animated)

 * In the film version of A Scanner Darkly, Mark Turner plays "Hank", who is later revealed to be.
 * In Batman Beyond: Return of the Joker, The Joker (Mark Hamill) is actually revealed to be . To make it more surprising, there is.
 * The writers of DCAU Batman LOVE this trope. In Batman: Mask of the Phantasm, the titular Phantasm is initially voiced by Stacy Keach, who also plays . This is a red herring, however, as the Phantasm turns out to actually be.
 * And also in Batman: Mystery of the Batwoman, where Kyra Sedgewick voices the titular Batwoman, but none of the suspects for the identity..
 * We Are the Strange does this. It's possible that the voice that speaks thorugh the SinisteRRR game (which is actually the voice from Sinistar), is also who is played by M dot Strange (the director), However, the film is really really confusing, so it's hard to tell if this really is an example or not.
 * For all the viewer knows, SinisteRRR is and is simply repeating a mantra that  taught it.

Film (Live Action)

 * The Adventures of Captain Marvel: To keep audiences from figuring out which of the scientists is secretly the Big Bad, the studio brought in Gerald Mohr to do the Big Bad's voice all the way up to The Reveal. Really comes in handy when.
 * Spoofed in Casino Royale 1967, where is revealed to be Dr. Noah, the Head of Smersh despite his voice not even remotely sounding like Valentine Dyall, who voiced the doctor all the way up until that point.
 * In Psycho, doesn't play Norma Bates until the very end of the film. Up until that point, the role was assumed by several different actors.
 * In the 2007 David Fincher movie, Zodiac, no less than 3 different actors (Richmond Arquette, Bob Stephenson, and John Lacy) are used to play the titular killer (always seen either wearing a mask or as a silhouette). Late in the film, a potential suspect is revealed and is played by Charles Fleischer. Despite his looking nothing like the 3 Zodiac actors, the film never 100 % clears him. The last we see of him, the possibility that he could be the killer is still somewhat open.
 * Also, John Caroll Lynch plays Arthur Leigh Allen, probably the most famous Zodiac suspect. However, Lynch matches the basic body type of the 3 Zodiac actors, so he's not as dramatic or as shocking of an example as Fleisher is.
 * In The Usual Suspects, Keyser Soze is played by multiple people before being . This is more a case of The Rashomon overlapping with Unreliable Narrator, though.
 * A deleted scene in Secret Window (that was not from 's perspective) shows.
 * A twist near the end of Dungeons and Dragons: Wrath of The Dragon God is that . Until he is unmasked (both to the cast and the audience), he is played by 's actor.
 * In Return of the Jedi, Pat Welsh voices the Bounty Hunter, Boushh, who later turns out to be in disguise.
 * In Velvet Goldmine,.
 * A vocal variation of this was done in the Lord of the Rings movies. In the scene where
 * Every Dario Argento film features shots where we only see the villain's hands, which are actually those of Argento himself.
 * In High Plains Drifter, there is a deliberate ambiguity as to the identity of the Stranger played by Clint Eastwood. He might be the brother of the murdered marshal, or there might be a supernatural explanation including but not limited to him being the ghost of the marshal, Satan, or an angel. When the marshal's murder is shown in flashbacks, he's played by Buddy van Horn, a stuntman who doubles for Eastwood and looks a lot like him (but different enough to aid the ambiguity).
 * In Sherlock Holmes, the actor providing the voice for  is uncredited, and it is unknown who it is (The Other Wiki indicates rumors of it being Brad Pitt, although an Ed Tolputt is credited as "Anonymous Man", so it might be him). In the sequel film, the character is played by Jared Harris.
 * In Sherlock Holmes, the actor providing the voice for  is uncredited, and it is unknown who it is (The Other Wiki indicates rumors of it being Brad Pitt, although an Ed Tolputt is credited as "Anonymous Man", so it might be him). In the sequel film, the character is played by Jared Harris.

Live Action TV

 * Used for a plot twist near the end of A Warning To The Curious where the ghost (John Kearney) tricks both the protagonist and the audience by disguising as, and, for that scene, is appropriately played by.
 * The first appearance of in Star Trek: The Next Generation  had her standing in the shadows, and played by a different actress (although  did provide the voice). Notably,
 * Kamen Rider does this a lot. The human and Monster of the Week forms of the bad guy usually have the same actor... except when The Powers That Be need to hide who the bad guy is. Never an in-story reason for the voice changing happening sometimes but not other times.
 * In the Doctor Who serial Remembrance of the Daleks
 * The Fresh Prince of Bel Air episode "Fresh Prince: The Movie" had Will tell about John "Fingers" O'Neill (played by Brad Garrett) after Will and the Banks family after Will witnesses a mod killing.
 * Person of Interest in what may have been a simple recast, had archenemy Root played by one actress in the character's debut, with the Camera only showing glimpses from odd angles, or her hands while typing... in the season Finale she was played by a second actress

Puppet Shows

 * In the Sandra Bullock episode of Muppets Tonight, the Mad Bomber who threatened to blow up the studio if the ratings dropped below fifty was a blue Muppet voiced by Jerry Nelson. At the end of the episode, the Bomber pulls of "his" entire Muppet form as if it were a mask, and is revealed to be Sandra Bullock herself.

Radio

 * AREM (voiced by Bob Lutrell) is an alias (voiced by Steve Burns) uses in Adventures in Odyssey. Justified in that AREM is a computer voice  uses to hide his identity.

Video Games

 * The RED Spy when he's disguised as in Team Fortress 2's "Meet The Spy" video is voiced by the latter's VA until The Reveal.
 * In-game, when a Spy is disguised, his voice also changes to match his class.
 * A very odd inversion occurs in Myst IV: Revelation. Pretty early on, it's established that (Brian Wrench) is still evil and that you'll ultimately have to fight him. While this is technically true, by the time you face off with him he's now disguised as  and is thus now being played by . It's also notable in that The Reveal is done without the non-mask actor being shown.
 * In the first Icewind Dale game, John Kassir plays, while David Ogden Stiers plays . Then, for good measure, once The Reveal is made, the character breaks into a fit of demonic laughter and (for his remaining 20 seconds of screentime) is played by Jim Cummings.
 * Another Bioware title, the first Baldur's Gate game, does this too. When, first approaches you as his alias, Koveras, he just uses one of the stock voices you've already heard several times earlier in the game ("You need something, stranger?").
 * However, if you're fast enough to click on him as he is leaving, you'll hear Kevin Michael Richardson's very distinct voice instead.
 * Done in-universe in Strong Bads Cool Game for Attractive People: Dangeresque 3: The Criminal Projective. Strong Sad plays five informants, one of which is actually Perducci (The King of Town) in disguise, but Strong Sad continues playing the role until The Reveal.
 * In Ratchet and Clank: Locked and Loaded, the thief is voiced by Rodger Bumpass. That is, until his voice modulator falls off and he is revealed to be.
 * Played for Laughs in Psychonauts, where the thin, agile Phantom turns out to be the morbidly obese inner critic Jasper rather than the more obvious suspect, Becky. Of course, since this all takes place in a crazy woman's brain this is somewhat justified.
 * In BioShock (series).

Web Animation

 * Very much played for laughs in this Homestar Runner cartoon, where voices a character who...turns out to.

Western Animation

 * In The Spectacular Spider-Man, Steven Blum voices the Green Goblin, but not his civilian identity,, voiced by Alan Rachins.
 * In the final episode
 * An episode of U.S. Acres had a character who looked and sounded like Orson Pig (voiced by Gregg Berger), but is later revealed to be wearing a mask.
 * Subverted nicely in the Galaxy Rangers episode "Mindnet." Henry Mandell does a really awful job of imitating Doug Pries's character, tipping off the audience that there's a big problem.
 * The episode, "Almost Got 'Im" in Batman the Animated Series focused on a meeting among various members of the rogue's gallery as they swap stories. Near the end, it turns out that.
 * And for a DCAU trifecta, when Superman impersonated Batman in the Superman the Animated Series episode "Knight Time", his disguise voice was provided by Kevin Conroy. The tongue-in-cheek reason? "Precise muscle control."
 * Which makes sense when you consider a specific trope that Superman named. In that instance, Superman spoke of staying in control and keeping himself in check at all times. Certainly he's had time to practice what he can actually do with that control.
 * Well, that, and it's a shout-out to the early days, when the explanation for why nobody knew Superman was Clark Kent was that he used "precise muscle control" to re-shape his face. Not sure which identity used the fake face.
 * In Scooby Doo Mystery Inc. the Monster of the Week (a vampire) is believed to be Daphne's mom. She even has the same VA, Kathy Soucie.
 * Usually the Scooby Doo villains will have their same voice actor, even when in disguise. There were a few exceptions, in the episode A Gaggle of Galloping Ghosts, when the female gypsy fortune teller (voiced by June Foray) was revealed to be, and on the episode Scooby's Gold Medal Gambit, the Master of Disguise The Chameleon disguises himself as Scooby-Doo at one point in the episode, and his disguised voice was provided by Don Messick instead of his regular voice actor.
 * In the Rocko's Modern Life episode Pranksters, Filburt (voiced by Doug Lawrence) impersonates Rocko's grandmother as an April Fools' Day prank on Rocko and Heffer. When in the disguise, "Granny Rocko" is voiced by Carlos Alazraqui (essentially doing a cranky, higher-pitched version of his Rocko voice).
 * In the appropriately named Transformers Generation 1 episode "Masquerade" five Autobots impersonate the captured Stunticons due to "camouflage paint." Windcharger becomes "Wildrider," Jazz becomes "Dead End," Mirage portays "Drag Strip," "Breakdown" is played by Sideswipe and Optimus Prime mimics "Motormaster." Before they go meet Megatron in disguise, "Drag Strip" is voiced by Frank Welker and "Motormaster" by Peter Cullen (the respective voice actors of Mirage and Optimus). When in disguise around the Decepticons, "Wildrider" is voiced by his usual voice actor, Terry Mc Govern, while "Motormaster" is played by Roger C. Carmel, Motormaster's voice actor.
 * The animated version of "The Mask" had a group session where Dr. Newman had the villains who fought the Mask recount their experiences. However, it's revealed
 * The 1980's Teenage Mutant Ninja Turtles used a Freaky Friday Flip to swap the minds of Shredder and Master Splinter in one episode. While they thought in their "real voices" with their appropriate voice actors, they still publicly "spoke in character"--Shredder was still voiced by James Avery and Peter Renaday still voiced Master Splinter.