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Part 31
XCOM: Enemy Within

Part 31

Learn how to complete the extraction mission and defend your XCOM base in Part 31 of the XCOM: Enemy Within guide.

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Learn how to complete the extraction mission and defend your XCOM base in Part 31 of the XCOM: Enemy Within guide.

Walkthrough
  1. 1
    For the extraction mission, move your soldiers to the extraction point. Kill Chryssalids as necessary and avoid being surrounded. Chryssalids can spawn from previously non-bursting pods. Consider using explosive abilities or flamethrowers to aid your escape. Extract at least one soldier to win, leaving others behind.
  2. 2
    For the XCOM Base Defense mission, the game auto-selects your highest-ranking and high-stats soldiers. Ensure these soldiers are properly equipped before the mission begins, as the game does not auto-equip them.
  3. 3
    The mission starts with two soldiers in the command section, with aliens entering through the ceiling and underground tunnels to the left. XCOM security personnel with rifles and grenades will assist; these personnel are expendable.
  4. 4
    Brad may open security doors, potentially yielding more soldiers and security personnel, especially if personnel have died.
  5. 5
    After the first wave, aliens will attack from the MEC bay (right) and tunnels (left). Cyberdisks will appear from the tunnels, and Mutons from the MEC bay. Cyberdisks may get stuck at command section doors, and Mutons can be easily dealt with from high ground overlooking the MEC bay.
  6. 6
    Subsequently, aliens will emerge from exploding tunnels on the far right. Depending on your game progression, you may face an Ethereal, Sectopods, or a Mechtoid.
Tips
  • For the extraction mission, focus on reaching the extraction point. Dash away from enemies if they have already moved and cannot attack.
  • For the XCOM Base Defense mission, equip your best troops with their necessary weapons.
  • Utilize the high ground in the command section of the XCOM base for significant combat bonuses. Camp here rather than engaging aliens on level ground in the MEC bay or eastern tunnels.
  • The rewards for the extraction mission are not great, and you can choose to ignore it.
  • The XCOM Base Defense mission is not difficult unless you have pressed the 'make items available' button on the squad selection screen, which may lead to under-equipped soldiers.
  • Expendable XCOM security personnel do not appear on the memorial wall if they die.

Base Construction Example (DLAI Method):

The player's base construction example includes specific placements of Satellite Uplinks, Power Generators, Cybernetics Lab, Officer's School, Workshop, Genetics Lab, Alien Containment, Foundry, and Thermo Generator across three floors. This example prioritizes building an Officer's School and a sixth Satellite Uplink by the end of the second month, and saving Meld for a Tier 3 MEC. Capturing aliens was deemed unnecessary due to moderating panic bonuses and the lack of the 'we have ways' bonus.

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