!The series as a whole
* DuelingGames: Friendly, with the {{Quake}} series, natch. Specially, ''VideoGame/QuakeIIIArena'' vs. ''VideoGame/UnrealTournament'', (being the greatest FPS feud of all time, and one of the ultimate cases of InternetBackdraft in its time) and to some extent, ''VideoGame/QuakeII'' vs. ''Unreal''.
* HeyItsThatSound: If you're a fan of the Unreal games, you'll notice that there're several event/weapon/explosion/ambient sounds carried from older Unreal games. Hell, you can even hear some sounds from the first ''Unreal'' game in some stages of ''Unreal Tournament III''.
* PromotedFanboy: The first Unreal Tournament came to the stores with around 8 mappers having worked on it, some of them gathered from the same Unreal community. The game was a success. Also, its modding and mapping community grew very well. By the time Unreal Tournament 2004 came out, the quantity of mappers grew up to almost 20. [[http://ut2004stats.epicgames.com/index.php?stats=maps The most played map of the game]], Rankin, which also made its way onto the demos, was made by the community mapper Hourences. He also made the most played Onslaught map of the game, Torlan, also in the demos as well. Both maps were made for that game in particular. Hourences is now working on the RPG ''The Chronicles Of Spellborn'', and has released two books called "The Hows and Whys of Level Design".\\
Due to this, Epic Games tried to do [=UT3=] more "modding friendly", and the success it has [[InternetBackdraft is still up for debate]].
** In an interesting bit, before the launch of ''Unreal Tournament III'', [[http://utforums.epicgames.com/showthread.php?t=576680 a short contest]] was done in the Epic Forums, to give a name to a map. [[http://utforums.epicgames.com/showthread.php?t=577156 The winner was keyrat]], who was credited in the game.
* WhatCouldHaveBeen: There was a cancelled project called ''Unreal Warfare'', which became ''GearsOfWar'', according to WordOfGod. The name was used again to refer to a new gamemode for ''VideoGame/UnrealTournamentIII'', which ended up being basically Onslaught's power-cores-and-nodes with Assault-style mini-objectives added.
** In a lesser note, Vehicle Capture The Flag is a standard game mode in [=UT2004=], however as no maps shipped with the game that use the [=VCTF-=] prefix (and thus are recognised by the game as Vehicle [=CTF=] maps), the game mode is [[DummiedOut hidden]]. Only by downloading and installing user-made maps for the game mode can you play it. By [=UT3=], Vehicle Capture the Flag lost it's identifying prefix, meaning some regular Capture the Flag maps would have vehicles to use, and others wouldn't.

!Trivia about the Unreal engine
* Unreal Engine 3 is one of the most licensed video game engines of all time, with it being used to power games across multiple genres. Mostly sticking to first and third-person shooters like Epic's own ''[[{{VideoGame/Bulletstorm}} Bulletstorm]]'' and the ''[[{{VideoGame/Borderlands}} Borderlands]]'' series, however other genres have been made on the Engine, including [[VideoGame/BatmanArkhamAsylum superhero]] [[VideoGame/BatmanArkhamCity brawlers]], [[VideoGame/InjusticeGodsAmongUs fighting]] [[VideoGame/GuiltyGear games]], [[VideoGame/LollipopChainsaw third-person hack-and-slash-]][[VideoGame/Warhammer40000SpaceMarine and-possibly-shoot]] games and [[VideoGame/XComEnemyUnknown turn-based games]].