Sometimes, you just can't help it: You need a Fake Shemp.

Sam Raimi, the director of films including Spider-Man and Army of Darkness, coined the term, which refers to the stand-in required to replace an absent actor onscreen. The first Fake Shemp was employed in 1955, when one of the Three Stooges, Shemp Howard, died with the group owing Columbia Pictures four short subjects. To finish them up, Shemp's stand in, Joe Palma, appeared in the films, but with his back to the camera.

Since then, Fake Shemps have appeared repeatedly. While they originally were other actors or stunt performers, the field has expanded to include digital replacements. Here are 11 cases when real actors were replaced by Fake Shemps, with directors crossing their fingers that no one would notice.

1. Bela Lugosi

In the annals of bad cinema, Ed Wood's Plan 9 from Outer Space (1959) features a legendarily bad double of the iconic Lugosi. The Dracula actor died after only a couple of days of improvisatory filming (Wood hadn’t even come up with a concept for the movie yet). The elderly Hungarian was eventually replaced by a chiropractor, who was taller and looked almost nothing like him. To compensate, Wood had the stand-in hold a cape over his face.

2. The Evil Dead cast

Still from 'Evil Dead' / Crave Online

Raimi formalized the term while filming the first Evil Dead movie in 1979. According to star Bruce Campbell, the movie’s stars weren't always available (it was an extremely low-budget production), and there were frequent special effects shots of characters covered with gore or turned into zombies. Raimi thus enlisted a veritable army of Fake Shemps -- the film’s credits list 18 -- to fill in as both monsters and doubles for his absent stars. Most of Raimi’s films since then have included Shemps in the credits.

3. Gene Hackman

The creation of Superman II was rife with conflict. Director Richard Donner shot most of the movie simultaneously with the first Superman. But he wasn’t allowed to finish the second film, being replaced by British comedy director Richard Lester. Gene Hackman, who played Lex Luthor, refused to have anything to do with Lester’s reshoots. Therefore, he was “Shemped” in a handful of shots by stand-ins and vocal impersonators. Despite all this, the 1980 release has become a fan favorite.

4. Tom Baker

The longest-serving Doctor Who had been gone from the show for only two years when producers decided to make a team-up episode called “The Five Doctors,” featuring all the actors who had played the Gallifreyan up to that point. Unfortunately the very first Doctor, William Hartnell, had been dead for eight years, so the role was recast. (One semi-Fake Shemp already!) But Baker refused to take part, saying he couldn’t return after such a short time away. His appearance in the 1983 episode was thus taken from old footage, shot for an abandoned episode. And when he refused to even show up for a publicity photo, producers put in a call to Madame Tussauds and used their wax dummy instead.

5. Harrison Ford

When the actor hurt his back while filming 1984’s Indiana Jones and the Temple of Doom, director Steven Spielberg didn’t miss a beat. He rearranged the schedule and kept filming, using Ford’s stunt double. The amazing part? Ford’s double, Vic Armstrong, looked so much like him that it’s difficult to tell what scenes he’s in. Spielberg even confused the two on set. According to Ford, “We could go home to the wrong wives and they wouldn't notice!”

6. Crispin Glover

Who doesn’t love George McFly? Marty’s adorably dorky dad in 1985’s Back to the Future was played impeccably at two ages by Glover. But when it came time to negotiate his role in the two sequels, something went awry, and Glover refused to return (he either demanded a preposterous amount of money or was offered insultingly too little, depending on which side you believe). Director Robert Zemekis therefore cast Jeffrey Weissman in the role. Weissman was disguised with prosthetic makeup and sunglasses, turned upside down, and intercut with footage of Glover from the first film. Glover ultimately sued over the use of his likeness; the Screen Actors Guild barred such moves in future films.

7. Brandon Lee

Still from 'The Crow' / TV Guide

Until this point, the Fake Shemps we’ve seen have been analog. But with 1994’s The Crow, digital Shemps made an early appearance. Lee was fatally shot while filming a scene, meaning that filmmakers had to scramble to rescue the film. As usual in such cases, a stand-in was used, along with repurposed footage. But a digital “mask” of Lee’s face was also used to disguise his stand-in. And such trickery was only getting started.

8. Nancy Marchand

Manipulative matriarch Livia Soprano was a highlights of the first two seasons of HBO’s groundbreaking series The Sopranos. But after actress Marchand died in 2000, series creator David Chase was left with with the problem of filming an appropriate exit for the character. His solution -- using old clips of Marchand, as well as digitally pasting her head on a stand-in’s body -- wasn’t particularly well received.

9. Oliver Reed

The burly, brawling Reed died during the filming of director Ridley Scott’s Gladiator (2000). How did Scott deal with the challenge? Stand in? Check. Digital mask? Check. This time, though, the digital trickery looked reasonably convincing. The price tag for such Shempery -- some $3 million -- probably explains its effectiveness.

10. Heath Ledger

When the 28-year-old Ledger died from a drug overdose in 2008, he was in the middle of filming Terry Gilliam’s The Imaginarium of Doctor Parnassus. For Gilliam, who has a legendarily difficult time getting his films financed and finished, it might have seemed like the end. But his daughter Amy, serving as a producer on the film, persuaded him to persevere. Gilliam ended up enlisting Johnny Depp, Jude Law and Colin Farrell to play other incarnations of Ledger’s character, adding an even more surrealistic element to the movie.

11. Natalie Portman

The Oscar-winning actress wasn’t available for reshoots for Thor: The Dark World (ostensibly because she was working on another project, but possibly out of embarrassment for being in yet another Thor movie). Star Chris Hemsworth’s wife, Elsa Pataky, stepped into the breach, and appeared as Portman’s double for a kissing scene.

All images courtesy of Getty Images, unless otherwise noted.