* KeepCirculatingTheTapes: With its mysterious removal from the App Store and Google Play, it is no longer possible to obtain Shadow Vanguard.
* TheOtherDarrin:
** John Clark was played by Creator/WillemDafoe in ''Film/ClearAndPresentDanger'', but the first game had him voiced by Douglas Rye instead.
** Between the two ''Vegas'' games, every voice actor except Jung Park's (Paul Sun-Hyung Lee) was replaced.[[note]]Denis Akiyama, the voice of Kan Akahashi in the first ''Vegas'', is credited for the same character in ''Vegas 2'', despite the character not having any speaking role in the game other than multiplayer voice lines.[[/note]] Particularly notable in that a lot of the characters in ''Vegas 1'' had distinctive accents that, except for Michael Walter (from Isaac Singleton to Kwasi Songui), the replacement actors [[NotEvenBotheringWithTheAccent did not bother to replicate]].
* NoExportForYou:
** The South Korean-made game ''Take-Down - Missions in Korea''. It was supposed to get a worldwide release, but it never happened.
** Due to the poor reception of ''Critical Hour'', plans to release the game outside of North America were cancelled, along with ports to other platforms.
* RecycledScript:
** The plot of the ''Vegas'' games is very similar to that of the ''Black Thorn'' ExpansionPack for ''Rogue Spear'', though considering the obscurity of the expansion, it might have been accidental. The plot of ''Black Thorn'' involves an ex-SAS operator, who failed to get into RAINBOW (thanks to ColdBloodedTorture, leading to mental problems), masterminding terrorist attacks worldwide to prove how good (and petty) he is.
** To a lesser extent, the plot of ''Raven Shield'' also bears some noticeable similarities to that of the original game and novel. Terrorist attacks bankrolled by a hidden villain who turns out to be a friendly face, stealthily wiretapping the home of a political figure to see where they stand, the presence of neo-Nazis, and a climax involving the potential release of a deadly virus at a famous national event that will spread the virus all around the globe - the motivations are the only thing significantly different, as the first game's bad guys were a WellIntentionedExtremist group trying to save the environment by killing off the rest of humanity before they could destroy the Earth, while the third's was simply a dying old man acting on [[UsefulNotes/WorldWarII sixty-year-old hatred]].
* TroubledProduction: The original went through this, mostly due to Red Storm's inexperience with game development[[note]]It was only their second official game - their first being a SoOkayItsAverage Clancy-inspired RTS game called ''Politika''[[/note]]. This [[https://www.eurogamer.net/articles/2015-12-04-the-agony-and-ecstasy-behind-the-first-rainbow-six retrospective/interview describes the process in pretty vivid detail]].
* WhatCouldHaveBeen
** The first game in the franchise began life as a tactical shooter based on the FBI Hostage Rescue Team. It was changed to an adaptation of Tom Clancy's novel to give it more appeal to international audiences. Amusingly, the devs later got to basically make the game they originally envisioned; the LicensedGame to ''Film/TheSumOfAllFears'' puts you in the shoes of the HRT for a mission or two and plays very similarly to ''Rainbow Six''.
** Before ''[[VideoGame/RainbowSixSiege Siege]]'', there was the unreleased ''Patriots'' with the basic premise being domestic terrorism, making split second decisions on whether that woman in civvies and wielding a gun is a threat or not, and having to make the call on whether a hostage with bombs strapped to him should be shot or risk terrorists using him as a suicide bomber. It even got a special weapon paint scheme in ''VideoGame/GhostReconFutureSoldier'' and another trailer showcasing Rainbow being trained in South Korea's head-first fast roping (virtually running down the side of a building) before the game disappeared completely.