XCOM: Enemy Within is an expansion pack for XCOM: Enemy Unknown. It was released on November 12th, 2013 in North America and November 15th 2013 elsewhere. Announced at Gamescom 2013, XCOM: Enemy Within adds new abilities, upgrades, weapons, and a new soldier class to combat new enemy threats. This expansion pack also introduces new resources, new maps, new tactical and strategic gameplay, and new multiplayer content.

XCOM: Enemy Within won Best Strategy/Simulation Game of the Year at the 2014 D.I.C.E. awards.

XCOM: Enemy Within is available as a download for PCs and Macs for $29.99. For consoles it is only available in disc format as XCOM: Enemy Within – Commander Edition, a standalone expanded experience that includes all XCOM: Enemy Unknown content plus the Elite Soldier and Slingshot add-ons, for $39.99.

XCOM: Enemy Within became available as a mobile app download for select iOS, Android and Amazon Fire devices on Nov. 12th, 2014 for $12.99. The following day, 2K Support released an iOS/Android XCOM: Enemy Within FAQ to address common questions regarding the mobile port; notably it clarified that the Elite Soldier, Operation Slingshot and Operation Progeny content are not included in the mobile versions.


XComEW Meld symbol.png
XComEW Meld symbol.png
XComEW Meld symbol.png

Meld is a new resource found in canisters that can be recovered during most mission types. Recovering Meld opens up a new research project called Meld Recombination, which unlocks two new base facilities: a Genetics Lab and a Cybernetics Lab. In the Genetics Lab, Meld can be used to grant soldiers super-human abilities through Gene Mods. In the Cybernetics Lab, Meld can be used to transform soldiers into MEC Troopers and to build MECs for them to use in combat.

  • The addition of Meld doesn't significantly change the research/tech tree; instead, most Meld-related tech and upgrades are unlocked as part of existing research, such as alien autopsies.
  • Although using this resource requires the construction of two extra facilities in the base, the Genetics Lab and Cybernetics Lab count as a Laboratory and Workshop, respectively, for the purpose of adjacency bonuses.

The five types of genetic modifications cost Meld5 - 35 each- a maximum of Meld130 for the more expensive of each body area, while a max level (3) MEC suit costs Meld210 (including the Meld10 for the augmentation of the pilot). 

Gene Mods[]

  • Alien Autopsies reveal genetic modifications ("Gene Mods" or "G-mods") which can be applied to soldiers in the Genetics Labs.
  • Any soldier (except MEC Troopers) can receive Gene Mods. A genetically modified soldier can undergo Psi testing and the modifications stack with Psi abilities.
  • Soldiers with Gene Mods receive unique versions of the various armor types (featuring sleeveless armor designs and their own armor deco options) and have access to eight different armor deco options just for them.
  • Gene Mods can be applied to a soldier's: Brain, Eyes, Chest, Skin, and Legs. There are two options available for each type (and they can be swapped at a cost).
  • Applying Gene Mods costs varying amounts of credits and Meld and removes a soldier from active duty for about 3 days per mod.

MEC Trooper[]

  • With the Cybernetics Lab, MEC Troopers can be created from any soldier class, maintaining their rank but losing all abilities and Gene Mods they previously had; Rookies cannot become MEC Troopers. MEC Troopers replace their arms and legs with cybernetic implants but remain human enough to be affected by Psionic abilities, including Mind Control.
  • MEC Troopers cannot be genetically modified or undergo Psi testing; a Psionic soldier cannot become a MEC Trooper.
  • A MEC Trooper does not use regular equipment in combat but instead utilizes a Mechanized Exoskeleton Cybersuit (aka MEC Suit). MEC Suits grant MEC Troopers armor and several additional bonuses, and can be armed with a Minigun, Railgun or Particle Cannon; as a disadvantage, MECs are incapable of using cover. MEC Suits can be upgraded through three tiers, each of which has a different name, set bonus stats and selection of Tactical Subsystems.
  • MEC Troopers retain and gain experience and ranks conventionally and have their own unique training tree.
  • MEC Suits have armor deco options that paint different patterns on the suit.

New Enemies[]

New Aliens[]

The expansion introduces two new alien types:

XCOM EW Mechtoid.png

The Mechtoid is a Sectoid in a mechanized suit. It is a robotic unit armed with twin Plasma Mini-Cannons and can fire twice in a turn if it doesn't move. Mechtoids don't utilize cover but have a solid block of health (20 HP on normal difficulty). Sectoids can Mind Merge with a Mechtoid to give it a Psi Shield which grants a health buff and reduces damage against the Mechtoid by half. Mechtoids are first deployed during the fourth month, along with Cyberdiscs.

XCOM EW Seeker.png

The Seeker is a flying squid-like robotic unit. Capable of cloaking themselves for a limited number of turns, Seekers utilize a brand new AI that focuses on hit and run style attacks. Seekers are spotted in pairs but largely act individually (i.e. can strike during different turns) and have a preference for attacking isolated units with their special Strangle attack. XCOM starts to encounter Seekers early in the game (mid-to-late April).


XCOM EW EXALT HiddenEnemy.png

The expansion introduces a new enemy faction in the form of a secret human paramilitary society titled EXALT. Its members work to disrupt XCOM's activities as they see XCOM as a rival in the acquisition of alien technology and an impediment to the aliens' human experimentation. To this end, EXALT sets up sleeper cells in Council nations around the world; the cell's hidden presence magnifies the effects of any panic the country may receive. Furthermore, a cell can go active, performing one of three different EXALT Operations against XCOM: Sabotage, steals funding from XCOM; Propaganda, increases panic in the country where the cell is located; or a Research Hack, reverses progress on the project currently being researched.

To counter EXALT's activities, the Council has provided XCOM with additional resources which can be accessed via a new Covert Operations menu in the Situation Room. From here the player is able to perform Intel Scans for hidden EXALT cells and launch Covert Operations against identified cells (but only one cell at time). Successful Covert Operations yield EXALT Intel that grants clues to the location of EXALT's main base. Once XCOM successfully identifies the EXALT headquarters, the player is able to initiate a base assault mission to eliminate the terrorist group once and for all.

XCOM EW EXALT Squadbig.jpg

In addition to the strategic threat posed by EXALT, the organization's operatives present a very real tactical threat during Covert Operation missions. EXALT introduces eight new enemies to the game: four standard units and four upgraded, genetically modified Elite units. These paramilitary agents may be dressed like bankers but they have abilities and equipment that match those utilized by XCOM. Also like XCOM, EXALT soldiers come in four classes that may be encountered in the field.

Class Changes and New Technology[]

Support Class

  • Covering Fire now fires before the enemy uses its weapon.
  • Smoke and Mirrors now provides two additional Smoke Grenade uses.
  • Deep Pockets now gives an additional charge to limited use items such as grenades, Arc Throwers, Medikits, etc.

Assault Class

  • Close and Personal now gives a free shot when within 4 tiles of an enemy. Cannot be combined with Run & Gun.

Heavy Class

  • HEAT Ammo damage bonus reduced to +50% against robots.
  • Grenadier now gives +1 damage to Frag, Alien and Needle Grenades in addition to its usual bonus of allowing a soldier to carry two in one item slot.

Sniper Class

  • Snap Shot aim penalty reduced from -20 to -10.
  • Squadsight only gives Critical Damage if Headshot is used.

New items:

New Foundry projects:

Gameplay and Interface Changes[]

  • The game intro receives a new quote, replacing the one from Arthur C. Clarke:
XCOM(EW) DevilsToys.jpg
  • There is a new tutorial mission introducing Meld that can be played in addition to or in place of the regular tutorial mission or disabled completely.
  • Enemies that don't utilize cover (Mechtoids, Cyberdiscs, Sectopods) may enter Overwatch when spotted.
  • Sectopods receive a new trait called Reinforced Armor that halves all incoming damage; this was added in order to increase their toughness compared to the Mechtoid.
  • Psionic powers remain largely unchanged except for some bug fixes related to some of the AoE abilities.
  • There have been several major bug fixes (including the "teleport bug" and a variety of cover-related bugs). There also has been a patch for the Slingshot Content Pack, as Shaojie Zhang can now be given custom facial hair and armor decos.
  • Panic was rebalanced to make it less likely for soldiers to fire on their squad mates; panic now includes an Aim penalty which also makes those rarer incidents of "friendly fire" less likely to hit.
  • The critical chance bonus granted to stealth attacks was reduced from 100% to 30%.
  • The Foundry now counts as a Workshop for the purpose of adjacency bonuses.
  • Laboratories offer some incremental protection against Research Hacks by EXALT.
  • Don't Die On Me has been removed from the Officer Training School due to the addition of the Secondary Heart Gene Mod. It is replaced with Lead By Example: The squad leader substitutes his or her Will for that of all nearby lower-Will squadmates.
  • Medals can be earned by completing certain tasks on missions and then can be awarded to individual soldiers. There are five different types of Medals. They can be renamed, and each type permits a choice between one of two buffs.
  • Normal difficulty may actually be slightly easier to beat due to the new tech, but Classic and Impossible difficulties have become more challenging; in addition to the threat of new enemies, research times, manufacturing costs, and experience required for soldiers to rank up have been increased.
  • New Second Wave options:
    • Aiming Angles: Units receive an Aim bonus the closer to flanking an enemy they are.
    • Save Scum: Loading a saved game resets the random number seed, so taking an identical action may yield different results.
    • Itchy Trigger Tentacle: Non-cover aliens (Mechtoids, Cyberdiscs, Sectopods) have a 50% chance of firing at a soldier upon being spotted.
    • Training Roulette: Each soldier's training tree is mostly randomly generated. Does not apply to MEC Troopers.
      • After a soldier receives a class and their first ability, additional ranks can grant randomized abilities from a pool of the all the class abilities sets minus any skills that are dependent on a specific weapons (which are still class-locked). So it becomes possible for an Assault to have Sprinter, or a Heavy to have Deep Pockets.
    • Mind Hates Matter: Psionic soldiers can't become gene modded or vice-versa.
  • Pre-mission/squad selection User Interface improvements: Equipped items now appear below each soldier's name and rank.  There is also a button ("Make items available") that strips all equipment from any soldiers not currently assigned to the Skyranger team.
  • The Memorial Wall now features "killed by" information with each soldier's name and which medals they were awarded.
  • There are new helmets, new armor decos for all armor types, and even new tint colors for customizing XCOM soldiers. Additionally, the color of weapons is now affected by the tinting option chosen for armor.
  • Players can now personalize their soldier's voice using the available audio packs for the current language localizations: French, German, Spanish, Italian, Russian, and Polish. Polish soldiers are now available for recruitment.
  • There is an option to disable Dr. Vahlen's and Dr. Shen's tutorial voice overs.

New Maps[]

  • There are new maps; 47 new maps officially, but is realistically about half that number due to Covert Operations (see below) re-utilizing new and old map types but requiring new squad and enemy spawn points. New map types include a bank, a new truck stop, a roadhouse, an ice cream shop, a coffee shop, a hydroelectric dam, a tire shop, a rural highway construction site and several new crashed UFO maps (notably a few urban crashes and one at a farm).
  • Some of the original Enemy Unknown maps have been "tweaked," some to address exploding cars issues and to add Meld canisters, while other have been adapted for new mission types. Use of the old and new maps is mixed, but the game is set so that the player sees more of the new Enemy Within maps during gameplay (for initial playthroughs but balancing out over time).

New Missions[]

Covert Operations[]

XCOM EW CovertOperative Surprise.png

Covert Operations are new tactical missions used to counter the threat posed by EXALT. Covert Operations are initiated from the Situation Room and require the dispatch of a Covert Operative. The Covert Operative remains unavailable for other missions during the several days in which they complete their assignment and then signal for extraction. If the Covert Operative is not extracted they are permanently lost. Extracting the Covert Operative requires the player to send a regular squad (which they control along with the Covert Operative) to complete one of two new Covert Operation mission types:

  • Covert Data Recovery: Requires the defense of an Encoder and a Transmitter against a large horde of aggressive EXALT agents in a "King of the Hill" type scenario until all enemies are eliminated.
  • Covert Extraction: Requires the Covert Operative to hack two specific EXALT Comm Arrays and then safely reach the extraction zone.  This mission does not actually require the complete elimination of the enemy for success.

There are 10 maps available for each mission type with some utilizing new maps introduced with the expansion and others give a new spin to existing maps.

Operation Progeny[]

XCOM EW ProgenyCharacter.png

The expansion includes Operation Progeny, a new set of three linked Council Missions which take place in France; like Operation Slingshot, it can be enabled or disabled separately from the game's advanced options menu. Narratively the missions involve of all three of the competing factions in XCOM: Enemy Within and have a tie in with the new XCOM Base Defense mission (see below).

The first Operation Progeny mission happens during the second month of the campaign and involves investigating a French military convoy that has been attacked; the mission can be extremely challenging on the higher difficulty levels. Much later in the campaign, XCOM receives the second mission which sends a squad to a hydroelectric dam to rescue a new playable character, Annette Durand; Annette is guaranteed to be Gifted if tested in the Psionic Labs. Operation Progeny's final mission takes place in the French Alps where XCOM attempts to rescue other civilians who were abducted.

XCOM Base Defense[]

XCOM EW BaseDefense EngineeringSabotaged.png

This is a new essential mission included in the expansion. This mission plays out on a massive new map which details Delta section, an area of the XCOM headquarters located behind Mission Control. The player initially controls a squad consisting of the top three soldiers from the Barracks (with whatever equipment they possess at the time the mission triggers) and several XCOM Base Security personnel (functionally Rookies with default equipment and slightly reduced stats). The squad must eliminate several waves of aliens, but receive additional reinforcements (groups of Security personnel and additional soldiers) as the mission progresses. Failing this mission results in a Game Over, but it can be restarted, even in an Ironman game.

Site Recon[]

XCOM(EW) SiteRecon Docks.jpg

A special Council Mission taking place in Canada.

It has chryssalids. A lot of 'lids. Bring a lot of firepower and fast troops, you'll need them.

Our sources indicate a developing incident in Newfoundland, up the coast from St. John's. A fishing village has gone dark: reports from intel sources suggest alien involvement. We should send a team to investigate the site and figure out what happened.


  • Players can now edit their squad and save several loadouts in offline mode.
  • Multiplayer unit costs have been rebalanced: Rookies and other basic units have received point reductions as have AoE weapons like grenades and rockets.
  • Mechtoid and Seeker added.
  • EXALT agents added.
  • Most aliens added.
  • 8 more maps for Multiplayer.


XCOM: Enemy Within has 30 new console achievements and trophies to unlock.


Official Screenshots[]

Additional Resources[]

Community 2K @ PAX Prime 2013
Strategy Masterminds Mega Panel @ the 5:45 hour mark
Interview with Lead Designer Ananda Gupta @ the 34 minute mark

Firaxis Developer Blogs
Q&A With Ananda Gupta on XCOM: Enemy Within
The Seeker
The Mechtoid
Who is EXALT?

Wikia Expert Showcase (Special Edition)
XCOM: Enemy Within Community Question Answers

Gameplay Videos
XCOM Base Defense mission playthrough with cutscenes