Aliens: Dark Descent is a squad-based tactical RTS in which players must command a squad of Colonial Marines as they battle against a rise of Xenomorphs across a variety of semi-open world missions. One of the game's key materials that players will have to acquire is Xenosamples, which can be used in the Otago's Laboratory to research Xenotech upgrades. These upgrades can provide a variety of bonuses to the squad before each deployment, and range from passive effects to specialized tools.
In order to unlock specific Xenotech upgrades, players will first be required to retrieve the Blueprints for the item, which will be located throughout the levels, most often as loot from defeating Queens.
10 Pheromones
Pheromones are a useful tool when it comes to stealth and keeping detection levels and enemy aggression low. When equipped, it will Reduce Alien Detection Time by 10%, allowing the squad more time to pass through precarious areas, such as around sleeping Queens.
The Blueprint for this particular Xenotech upgrade can be acquired by defeating the Queen in Hangar C of Berkley Docks. While this upgrade can be useful for certain missions, there are many better options available that provide greater benefits.
9 Soothing Serum
Reducing Stress is an important element of running a successful mission. Marines overcome with excessive Stress will gain penalties, which will render them less effective in combat. Fortunately, players can utilize the Naproleve drug to reduce Marines' Stress levels. While the standard application will reduce the Stress of a unit by 100, the Soothing Serum upgrade will bolster this to 150.
While this upgrade can be useful, particularly among squad members with less favorable Personality Traits, these afflictions are still bound to build up and are best treated at the Otago's Psychiatric Care Unit rather than in the field. This will free up important Medical Supplies for physical injuries, which could potentially be more detrimental to the health of the squad.
8 Chitin Kevlar Plates
Chitin Kevlar Plates are one of the first Xenotech upgrades players will be able to find in Aliens: Dark Descent. Once researched, all squad members will receive Armored Plating at the start of each mission, extending their health and giving them an extra barrier for a few encounters before the need to use Medical Supplies.
The Blueprint can be found in a chest in the 2nd floor Laboratory area of Dead Hills. This can be located via the sector map to the South of the Command Room. This upgrade is very useful early on, but since it is a passive upgrade and there are other ways of increasing armor points, it is not one of the best available.
7 Xeno-Zip
Xeno-Zip is a useful upgrade that will add 1 HP to every Marine in the squad at the start of the deployment. While it may not seem like much, this bonus can be the difference between life and death, and can greatly affect the rationing and distribution of Medical Supplies on a given mission.
The Blueprint for this Xenotech upgrade is found in the Queen's Lair in Jackson's Landing, and players will be required to defeat the boss to gain the blueprint. Like many other bosses in the game, the Queen will drop additional Xenosamples for players to collect, which can be used to research and apply the upgrade for the next deployment.
6 Pheromone Mine
The Pheromone Mine is a useful tool upgrade that will give the squad the benefit of an additional and specialized trap. Mines will now attract Xenomorphs with Pheromones provided that they are within the creature's field of view and that the squad is undetected.
The Blueprint can be found in the colony room on the surface during the mission "Atmospheric Nightmare." The room can be seen on the map to the left of the Laboratory, and the blueprint will be contained within a chest there.
5 Hive Tranquilizer
The Hive Tranquilizer upgrade can be used to delay the Aggressiveness of Xenomorphs by 15%, giving squad members more time to complete various objectives within a given location before increasingly difficult enemies will spawn.
The Blueprint can be located in the Montero area, on Deck Level B north of the Medbay. While not essential in earlier missions, this upgrade can make a big difference later on, particularly as the planet's infestation level increases.
4 Hive Jammer
The Hive Jammer is another useful passive upgrade that will shorten the duration of a Hunt by 15%. Hunts will begin when a squad is detected and engaged in combat for prolonged periods. This upgrade will also help slow down Aggressiveness levels since Hunts will be shorter.
The Blueprint is located in the Alien Queen's lair in Basement 1 of the mission "Extraction." Using a Marine in the Tekker class will unlock this room, and players will have to defeat the Queen to unlock the Blueprint.
3 Extraction Device
The Extraction Device is a tool that could easily be considered essential as soon as it becomes available. This tool will give Marines the ability to remove Facehuggers from any squad members who have one attached to them. Without it, there is virtually no way to combat a Facehugger once it has taken control of a squad member.
The Blueprint can be taken from the Xenomorph Queen in the Old Mine on the perimeter of Dead Hills. While the initial encounter with this boss is optional, it is worth taking it down to gain this Blueprint as well as additional Xenosamples.
2 Anti-Acid Gel
Anti-Acid Gel is another upgrade that might be considered essential since it addresses one of the fundamental issues of Xenomorph combat - their corrosive and damaging acidic blood. With this upgrade, Marines' armor will become immune from Acid damage, giving Marines better combat longevity.
This Blueprint can be acquired during the mission "Nuclear Protocol." Players must defeat the Xenomorph Queen and a variety of Synthetic enemies before they will be able to acquire the upgrade. The Queen's lair is located in the Cerberus Protocol Room of Pioneer Station.
1 Aerial Xenotoxin Application
The Aerial Xenotoxin Application fundamentally addresses one of the core challenges when it comes to gameplay difficulty in Aliens: Dark Descent - planetary infestation level. This upgrade will reduce the Infestation Level by 1 and can be used repeatedly. Each time the infestation level is reduced, Xenomorph Aggressiveness will also decrease, making Marine's lives significantly easier on deployment.
The Blueprint can be found during the mission "Extraction" and is located in Basement 1 Floor. Overall, this upgrade will make the most difference to the survival of the squad as a whole and will affect all locations that the player chooses to deploy in, giving them more time to complete each mission.
Aliens: Dark Descent is available now on PS4, PS5, Xbox Series X|S, Xbox One, and PC.