Niveus is a very vertical map, with 4 floors to it. Aside from the main stairwell, there are numerous ways to get around the level. The first level has the highway, the default human base, the back corridors, and the stairwell. Humans will want to move out of the default base as soon as possible, into either the back corridors or a room on the second level.

Immediately forward of the starting base. Can be useful if the humans attack early from above.

Not far from the starting base. One of the most popular alien bases as it has only one incoming attack route. However this means it has only one escape route too!

Easy to find. With three incoming routes not the easiest to defend.

Close to the human base. The central room has four doors - two blue doors which are the incoming routes, and two yellow doors leading to dead-end side rooms. This offers a wide range of possible base layouts in one, two or all three rooms. The ceilings are low which makes this base harder to defend in the later stages.

Has a high ceiling space and plenty of cover for structures. Has two incoming routes, one of which is up a steep flight of stairs giving defenders a height advantage.

The window room is perhaps the most well known base on this map, and therefore often the first place an opposing team looks to. This base is closer to the default alien base than the default human base, but it is better for a dretch to accompany any grangers.

The first thing an alien builder should do in the window room is to build an egg behind the boxes in the corner. The boxes provide some cover. The primary purpose of this egg is to allow defenses to be built around the door.

Acid tubes should be arranged around the door such that an attacker cannot walk through, only jump. If there are enough build points, three lines of acid tubes (one parallel to the door and two perpendicular, making a “box” around the door) can be built. This “box” pattern is effective because it does not immediately overwhelm attackers. A human is not critically hurt upon opening the door, so will tend to run forward into the base. At this point the attacker is susceptible to all of the acid tubes and, even if wearing light armor, will die almost instantly. At stage two, acid tubes will be relocated to above the door and the acid tubes on the ground can optionally be replaced by barricades. Barricades will not only stop humans from sprinting past defenses at the door, but will also deflect grenades out of the base.

At any point after some defenses are set up or other aliens are in the window room to defend, the overmind can be moved. The best place for the overmind in the window room is on top of the barrels in the corner. Because this corner is to the immediate left of the door, it cannot be shot unless a human has stepped through the threshold. Being on top of the barrels makes grenades and painsaws less effective, although it does not completely stop them.

Once the door is adequately surrounded by acid tubes and a barricade or two is between the overmind and door, a single granger can remain and all other aliens can focus on acquiring stage two. The last granger should build one or two “escape eggs”. These are undefended eggs hidden across the map far from base so that if the base happens to be destroyed a new base can be built. More eggs can also be placed in the window room.

Once stage two is acquired advanced grangers can climb the wall and improve the base. Acid tubes can be built on top of the two beams above the door. Acid tubes on top of the beams are harder for humans to attack. Acid tubes can also be placed on the sides of the beams, facing each other. Remember though - damage from acid tubes has nothing to do with the green “acid” blobs vomited from the tubes. It is only based on a human's distance from the tube itself.

The ceiling of the window room is slanted on the sides, making it hard to aim trappers directly in front of the door. But with practice, 2 or three can be placed. Trappers on the ceiling and barricades on the ground stop humans from sprinting through the door's defenses and entering the base unscathed.

Eggs can be placed on the roof and on the beams. It is best to build them such that they cannot be easily shot from outside the door. It is also a good idea to build boosters directly below the eggs so that spawning aliens will fall on them.

Once hives become available, they can be arranged on the wall on the side of the door and on the bottoms of the beams. Hives and acid tubes can also be placed on the wall directly above the door, but this location will block and trappers on the roof.

Remaining build points can be spent defending the hallways leading to the window room, in the window room itself, or building forward and escape bases.