Alien Base Terrain
The aliens will occasionally set up shop earthside in an underground base. Their operations need to be shut down, and the only way to do that is send troops in and clear it out. Alien bases are normally hidden on the Geoscape. To find them, you need to leave an X-Com craft flying over them for a short period. X-Com undercover agents will occasionally report a base location to you at the beginning of the month, but that shouldn't be relied upon.
Most of the base will be unlit or only partially lit; be prepared to fight in darkness. Expect a maze of corridors, with aliens lying in wait.
Alien bases are always entered through two large entry lift areas with bright green floors. The two lifts will be scattered randomly through the base. Most of your units will start on these areas, though depend on a couple to jump the gun and be waiting for orders in the base below.
The headquarters you attack on the second second stage of the Cydonia raid has the same layout as alien bases; only the command center is different.
Common Modules
See Xcom_and_Alien_Bases#Alien_Base for a full set of maps.
- Entry Lifts - where your soldiers start.
- Storage Rooms - Hangar-size rooms full of rows of vats, with a security watchtower in the centre. The ceiling is two levels up, the upper level is wide open.
- Storage Lofts - Single-square lift closets leading up to a second-level room chock full of vats. The southeast room will contain two UFO power sources.
- Checkpoint Closets - Four single-square lift closets connected by a U-shaped hallway on the upper level.
- Alien Gardens - Dark rooms with jagged rocks and strange pulsing mushrooms. The ceiling is two levels up -- the lower level is a claustrophobic maze, the upper level is wide open. Burn 'em.
- Alien Entertainment - Flashing walls and floors that you thought went out with disco in the seventies.
- Plasma conduits - explosive red pods.
- Command Centre - the double-walled area where you'll find the Base Commander and some consoles on the second floor. He often gets a Blaster Launcher and bodyguards.
- destroying the contents of this room on the second floor renders the base destroyed for all intents of a base assault.
Battle Notes
- The southeast room of the storage loft will contain two UFO power sources, and one of these sources will usually contain 50 units of elerium.
- Any large section of alien garden section is a warren. Completely dark and loaded with winding corners and small niches to hide in, they are the some of the most treacherous areas to fight in. However, the upper level is wide open. Use heavy weapons, saturate with explosives and use flying units to attack them.
- The storage rooms will be heavily populated with aliens, and expect one or two snipers in the central tower. The second level is wide open except for the tower, so flying units are helpful here as well.
- If you are trying to capture a commander, be aware that before entering the inner door of the command center, if the commander is not killed or incapacitated before the end of the turn where the door is opened, he may fire his blaster launcher and kill himself and most of the aliens in the command center accidentally.