Throughout the history of commercial arts, creators are limited by what's available and what they can afford. Sometimes the artist will be forced to go another direction. Many do it gracefully, others leave so much of their original idea in the piece that what remains can only be seen as a poor substitute.

This trope can apply to Actors, licensed Music, and anything that could have strings attached. Similar issues occur in the tropes CaptainErsatz, PoorMansSubstitute, and ReReleaseSoundtrack.

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!!Examples:

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[[folder: Films -- Live-Action ]]

* ''Film/StarTrekGenerations'''s producers hoped to get [=DeForest=] Kelley to appear as Dr. [=McCoy=], but due to his declining health, he could not get on-set insurance. Most of his lines in the opening scene were given to Pavel Chekov, which is why Chekov drafts reporters as nurses and heads to Sickbay. Scotty was given one line, asking Kirk if he wanted a tranquilizer. ([[http://www.imdb.com/title/tt0111280/trivia see here]])
** Likewise, they wanted Leonard Nimoy to play Spock, but when he declined his lines were given to Scotty.
* A music variant occurs in the final scenes of ''Film/TheDevilsAdvocate''. Evidently the filmmakers wanted to end the film with "Sympathy For The Devil" By Music/{{The Rolling Stones|Band}}. It would seem they had to settle for less appropriate "Paint It Black".
* A gender switch variant in ''Film/BallisticEcksVsSever''. The part of Sever was originally supposed to be male, but after Creator/LucyLiu was cast in the role the script wasn't changed to reflect this. That's why there's no {{UST}} between her and Ecks (Antonio Banderas) the way you'd expect. Source: Website/{{IMDb}} [[http://www.imdb.com/title/tt0308208/trivia Trivia]].
* In a college Q&A, Creator/KevinSmith discussed his experience with this. He wanted to use "The Most Beautiful Girl In The World" by Music/{{Prince}} in ''Film/JayAndSilentBobStrikeBack'' when Jay first sees Justice. Prince refused and offered him "Raspberry Beret" instead. When Smith tried to explain why that just didn't fit the scene, the [[CloudCuckooLander conversation went nowhere]], and he chose to go with "Bad Medicine" by Music/BonJovi instead.
* Creator/HalleBerry's role in ''Film/TheFlintstones'' was originally meant to be played by Creator/SharonStone. What makes this obvious? The character's ''name'' is Sharon Stone.

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[[folder: Live-Action TV ]]

* ''Series/GetSmart''. Don Adams was unavailable for the episode "Ice Station Sigfried" so Maxwell Smart's place was taken by a CIA agent named Quigly, played by Adams' friend Bill Dana. You can tell that very little rewriting was done to the script, and the writers simply gave Maxwell Smart's lines to Quigly.
* This happened a lot in classic ''Series/DoctorWho''.
** The most notable example is "[[Recap/DoctorWho20thASTheFiveDoctors The Five Doctors]]", which Creator/TerranceDicks wrote with actor availability in mind. Here is the problem: "The Five Doctors"' impressive cast forced Dicks to write those characters as generically as possible, ''and it's glaringly obvious'' in many places.
** "[[Recap/DoctorWhoS20E3MawdrynUndead Mawdryn Undead]]" was originally written as a return appearance by Ian Chesterton, but the actor was unavailable. It was rewritten for Brigadier Lethbridge-Stewart, but the school setting was retained, with a handwave about the Brig retiring from the military and becoming a teacher.

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[[folder: Web Original ]]

* Lampshaded in WebVideo/TheCinemaSnob's review of the ''Film/AClockworkOrange'' porn parody ''A Clockwork Orgy'', which replaces "Singing In The Rain" with "Take Me Out To The Ballgame":
-->'''Snob''': Oh yeah, Creator/GeneKelly's ''second'' most popular song! Let me guess, they're going to replace Beethoven with "On Top of Spaghetti"!
* In WebVideo/TheNostalgiaCritic's review of ''[[Film/{{Garfield}} Garfield: A Tale of Two Kitties]]'', he believes the character Lord Dargis, played by Creator/BillyConnolly in the film, was obviously written with Creator/JohnCleese in mind.
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