Easter Eggs are intentionally hidden messages, jokes, or features in XCOM: Enemy Unknown.
X-COM Arcade Game
The "X-COM Fighter Alpha" arcade game can be found in the Barracks facility in XCOM Headquarters and on the Bar map available in multiplayer or as a Terror Site mission. It features images of a soldier and a Sectoid from the original UFO: Enemy Unknown/X-COM: UFO Defense game.
While visiting the Situation Room, the comments Central Officer Bradford makes occasionally include hidden references:
- "We've been picking up some odd transmissions lately... some nut calling himself 'Commander Straker' has been all over the news ranting about shadow operatives."
This is a reference to Commander E. Straker and the SHADO agency from the 1970 UFO (TV series).
- "This is Central, I'm receiving you... what do you mean you think you saw a snake? What the hell does that have to do with anything?"
This is likely a reference to Snakemen, a species of alien from the original X-Com that was left out in this remake, though it is strongly indicated that they have been turned into the game's Thin Men. It could also be a reference to the returning reptilians The Vipers in XCOM 2. Alternatively, this could be a reference to Solid Snake from the Metal Gear Solid series, as this character can usually be found sneaking around in paramilitary bases, similar to the XCOM base.
- "Are you really using our tracking terminal to play Civilization?! I at least hope you're going for a Military Victory...."
This is a reference to Sid Meier's Civilization V, the other game that Firaxis was developing at the same time as XCOM: Enemy Unknown.
- "...and you are positive that a UFO crash landed in the low-downtown house backyard of a middle-class family... the Tanner residence. Roger, looking into it."
This is a reference to the TV sitcom ALF from the 1980s.
- "Don't patch that through - No....we're here to track alien activity, not investigate haunted houses."
This comment is added in XCOM: Enemy Within and is a reference to the iOS game Haunted Hollow released by Firaxis.
- "I don't want to hear anything else about forming an ace patrol... we don't have time for alien dogfights."
This comment is added in XCOM: Enemy Within and is a reference to the game Sid Meier's Ace Patrol also by Firaxis.
Like Bradford, Chief Engineer Shen may also make commentary in the Situation Room containing hidden references.
- "Men have fought for gods and kings alike, but now we fight for the survival of our species."
This is a reference to the first expansion pack of Civilization V, Civilization V: Gods & Kings.
- "I can only imagine the brave new world we have to face if the invaders succeed."
This is a reference to the second expansion for Civilization V, Civilization V: Brave New World, as well as the novel Brave New World by Aldous Huxley.
The comments made by soldiers during battle also occasionally include hidden references:
- When successfully using the Arc Thrower against an enemy, a soldier may comment with:
- If a MEC Trooper has been customized with the Polish language option, voice "1" (the "chill-out" one, or at least it's hard to hear this line from other voices), a successful kill may result in the MEC Trooper saying "A kto umarł, ten nie żyje" ( "And who died, is not alive" ).
The reports that players can read after the completion of the research projects include several hidden references and themes:
- Chryssalid Autopsy: Codename Ridley
Reference to the movie Alien, which was directed by Ridley Scott. The Chryssalid's abilities were partially inspired by the alien from the movie.
- Ethereal Device: "A team of brothers have already conceived of just such a facility."
The Gollop Chamber owes its name to the Gollop brothers, developers of the original game.
- Floater Autopsy: Codename Crimson Cape
Reference to the Floaters in the original game, who wear red capes.
- Hyperwave Communication: Codename Tachyon
Reference to a type of particle in the original game.
- Outsider Shard: Codename Novato
Reference to the location of 2K Games headquarters in Novato, California.
- Seeker Autopsy: Codename Lovecraft
Reference to Howard Phillips Lovecraft, horror fiction writer, creator of the Cthulhu Mythos.
- Thin Man Autopsy: Codename Viperus
Reference to the Snakeman alien in the original game (a Viper is a venomous snake). Vipers are also a race of alien in XCOM 2, theorized to be the original form of the Thin Man prior to heavy genetic engineering.
- Sectoid Autopsy: Codename Roswell
Reference to the Roswell Incident
- Several research project codenames are a species of bird:
|Alloy Cannon: Codename Avocet||Plasma Rifle: Codename Kestral|
|Heavy Plasma: Codename Kingfisher||Plasma Sniper: Codename Osprey|
|Light Plasma Rifle: Codename Corvid||Sectopod Autopsy: Codename Halcyon|
|Plasma Pistol: Codename Jacamar|
On the right most wall of the Research Labs facility the serial code OG 1994 is printed. This is likely a reference to the 1994 release date of the original game.
Test Firing Targets
After being built for the first time, both the Laser Rifle and Plasma Rifle each feature a test firing cinematic where the target is an image of an alien from the original game; a Sectoid and a Muton (respectively).
During the cinematic following shooting down the first UFO, the recon satellite imagery of the crash site displays a set of Latitude and Longitude coordinates (N 38 3.59562 W 122 30.958157) which correspond with the 2K Games Corporate Office in California.
During the cinematic where the Alien Base is revealed, the recon satellite imagery of the base displays a set of Latitude and Longitude coordinates (N 39 31' 16.68 W 76 38' 46.82) which correspond with the Firaxis Games studio in Maryland.
When renaming your soldiers, entering certain names will unlock "hero" characters with extraordinarily high stats and advanced equipment load outs. Activating any of these characters disables Trophies/Achievements for that game.
Inside the new bank map is a framed picture of producer Garth DeAngelis hanging alongside those of presumably some of the bank founders; Garth used to work as a VP for Bank of America before changing careers to work in the gaming industry.
During the Site Recon mission in Newfoundland, Bradford will comment on the crashed whaling ship stating "... at least it wasn't a cruise ship" and the after mission report mentioning alien interest in infesting marine life: A subtle nod to the infamous terror missions of X-COM: Terror From the Deep and the game itself respectively.
The Bureau References
The expansion also includes several nods to The Bureau: XCOM Declassified.
- A fedora makes an appearance as a new helmet/hair option available to soldiers.
- The project report for Meld Recombination contains a reference to "redacted data stores created in the 1960s".
- Renaming a soldier "William Carter" unlocks a new XCOM Hero.