Aliens: Dark Descent is based on the movie Aliens. It tries to create the same tense setting as the movie.

I will in this guide explain many game concepts and will give advice for three different types of players so that every player type will have a great time with this game.

This is important because the developers, in my opinion, has made the difficulty settings not reflective of the player type. I have also watched many online streams, and it occured to me that game mechanics I rely heavily on to beat the game on max difficulty is not even used by most players.

After selecting New Game, the campaign difficulty can be selected.
It is not possible to change the difficulty afterwards.

So the three player types:

Casual

• Gaming goal: Story and atmosphere
  
• Pause: Does not pause the game much
  
• Stealth: What is stealth?
  
• Reaction speed: Playing turn based
  
• Multitasking: One task at a time
  
• Typical fight: Likes to pet aliens
  
• Game mechanics: Not interested

Experienced

• Gaming goal: Both story and challenge
  
• Pause: Uses pause to give orders
  
• Stealth: Tries to use stealth
  
• Reaction speed: Normal reaction speed
  
• Multitasking: Can handle a bit happening at the same time
  
• Typical fight: Shotgun range
  
• Game mechanics: Interested in the basics

Expert

• Gaming goal: Story with a tough challenge
  
• Pause: Instantly pauses game based on sounds nearby
  
• Stealth: Uses stealth all the time
  
• Reaction speed: Fast reaction
  
• Multitasking: Master chef
  
• Typical fight: They never see me
  
• Game mechanics: Wants to know everything

Enemy hit points
Goes from about 10hp on easy, 20hp on medium to 30hp on very hard on a standard alien drone.
This compared to rifles doing about 2 damage per second(dps) we get about 8 dps on a squad of four marines. With aliens running very fast towards you, this setting changes the game completely. On open spaces you have about 4-5 seconds, but on closed spaces and small rooms you have less than two seconds to shoot aliens before they are in petting range.

Casual
Easy

Experienced
Medium

Expert
Very Hard

Enemy detection time
All enemies have different stages of alertness. Ranging from unaware of where you are, to you being detected. When there exists a direct line of sight between one of your marines and an enemy the detection timer starts counting down. This timer is visualized by a yellow line between the two. This line will start turning red from the enemy and move towards your marine until the whole yellow line has become red, indicating that the squad has now been detected.
This is when stealth ends, and a fight begins.
Having this on lowest setting just adds to the immersion. Setting this higher makes stealth harder.

Casual
Easy

Experienced
Easy

Expert
Very Hard

Aggressiveness incrementation delay
On the top right of the HUD the alien hive aggressiveness is shown.
It ranges from easy, medium, hard and finally maximum agressiveness.
It resets back to easy on every deployment on the same mission.
The higher this gets on a mission, the more aliens will hunt you, and they will tend to run more around searching. The game gets exponentially more difficult as this rises.
But it only rises when the squad is detected or hunted by aliens.
The normal play is to extract your squad, and redeploy a fresh rested squad if this gets too high.
This is the main reason for stealth in this game.

Casual
Easy

Experienced
Medium

Expert
Very Hard

Death clock campaign turns
At a certain point in the campaign a countdown will begin.
It ranges from 30 days on easy to 20 days on very hard. It can also be set to disabled.
When it reaches 1 day left, it means this is your final day, day 0 starts with game over screen.
This will also directly impact the ability to deploy multiple times on a mission, as you can only deploy once per day.
For some players this may be stressful.

Casual
Disable

Experienced
Easy

Expert
Very Hard

Save system
It has two modes.

Permissive
The game autsaves often, on every mission objective completed, elevator used, before many scripted events in addition to the normal saving, after resting, or after new day on the Otago.

No One Can Hear Them Scream(NOCHTS)
The game restricts save games to two slots. After resting on a mission and on the Otago.
No other autosaves. This means you need to plan ahead and sometimes force a rest to save.
As this game do not have any Ironman mode, this is the closest it gets.

Bugs
There exist game breaking bugs.
Bugs that only a reload may fix.
Most people will not encounter any bugs that halts progress, but some do.
I always play on NOCHTS, but in general advice it is not recommended.

Casual
Permissive

Experienced
Permissive

Expert
Permissive

Perfect Organism
This modifies the damage aliens does.
A standard alien drone does 1 damage per default.
A marine has 6 hp and 2 points of armor. Hitpoints can be healed up, but armor once lost is gone for the whole deployment.
Sentry turrets I believe have 4 hp.
I will advice a +1 damage adjustment for the Expert player, because that would take a marine down to 4 hp if no armor, and will still survive another hit. +2 damage if you really want to fear aliens coming close, but then a marine needs more hitpoints to survive two hits.
I always play on +5 alien damage, but I have played through the game a dozen times, and will on average be hit by aliens 1-2 times total in the campaign.

Casual
Default

Experienced
Default

Expert
+1 damage

We're too late
This setting modifies the infestation level of the planet.
It ranges from 1 to 5.
It impacts the number of roaming aliens at the same time on a map. And also the number of aliens that are sent from the hive during a massive onslaught event.
In my opnion, this should always be at 5. Because this is an alien game and we already adjusted alien hitpoints to fit the player type. I think it would lessen the game to reduce the ammount of aliens being slaughtered.

Casual
5

Experienced
5

Expert
5

Classes
There exists 5 different classes.

• Sergeant
  
• Gunner
  
• Recon
  
• Medic
  
• Tecker

When a marine reaches level 3, you get to chose one of two random classes to upgrade into.
The game increases the random chance to get classes that you have less of in the squad.
The choices may change if another marine picks one of the classes that another marine has been presented. One strategy is to level up marines that you are dissatisfied with and selecting classes you do not want for them, thereby increasing the odds of getting the correct class for the marine you want in your A-team.

Each class gets a unique attribute at levels 3, 6 and 10.

Also each class gets access to 3 additional upgrades unique to their class.

Max experience level in normal campaign is 10. For NG+ campaign the max level is 15.
There is enough experience in the campaign to get your A-team to level 10, but there is not enough experience to get two teams to level 10. So if you switch out marines from mission to mission, they will not reach level 10. Keep this in mind, as some really good attributes and weapons unlock at level 10.

I will in this guide give advice for each class according to the player type and above difficulty.

Sergeant
The sergeants main role is command point economy and stress control

Unique attributes
Charismatic (lvl3)
Increases bravery of every marine in the squad by 10 points
Bravery reduces incoming stress by a percentage.
Per default a marine has a bravery of 10%.
This attribute raises every marines bravery to 20%, including the sergeant.
Does not stack with other sergeants.

Reprimand (lvl6)
Grants the Reprimand skill. Costs 1 command point to activate.
Prevents stress from increasing on every marine for the next 30 seconds.
While active the skill Retaliation is unavailable.

Encouraging speech (lvl10)
This increases the ammount of stress reduction when resting by 50 points.
Default is 100 points of stress reduction on resting, bringing this up to 150 points reduction.
It stacks with other sergeants, giving additionally 50 points per sergeant.

Class upgrades
Radio backpack
Increases max command points by 1
Default max command points is 3, this upgrade will raise it to 4.
This stacks with other sergeants, giving you an extra command point per sergeant.

Advanced radio backpack
Regenerates command points 10 seconds faster.
Default is 60 seconds per command point, this upgrade lowers it to 50 seconds.
This stacks with other sergeants, reducing time by 10 seconds per sergeant.

Honour ribbons
Increases the marines bravery by 5.

My opinion
Besides shooting normally, when it comes to solving a tricky situation, you will need to use command points. The more dangerous the situation, the more command points you will spend.
So this means on the lowest difficulty command points hardly matters, while on the higher difficulty it may save your squad from a wipe. I think the Casual player and the Experienced player will want to bring one sergeant for spamming Reprimand to keep stress in check. But the Expert player may want to consider bringing 2-3 sergeants because of the reduction in command point regeneration time, and having a large command point pool is really nice when sniping from stealth.

Gunner
The gunners main role is dps and crowd control.

Unique attributes
Weapon training - M56 Smart gun(lvl3)
The marine can equip the Smart gun

Bone breaker(lvl6)
Increases by 1 point the dismemberment chance of the marines primary weapon.
Default is listed in the weapon description for each weapon.
Smartgun has default chance of dismemberment of 0.3 % per bullet.
This attribute would raise that to 1.3% per bullet.

Unleash hell(lvl10)
The higher the stress step of the marine is the higher their firing rate is.
At the start of a deployment, the stress step is 0. It can reach stress step 3.
Through testing it seems that each stress step increases the rate of fire by 33%.
At max stress level 3 this means 100% increased rate of fire, double dps.
This stacks with the Suppressive Fire skill to boost the normal smartgun rate of fire of 4 bullets per second to become 16 bullets per second. Adjusted for accuracy it is still impressive.
And then if combined with the Dead Eye skill(increase critical hits by 38%) Well, lets just say this is max dps.

Class upgrades
M56 ACT
Allows the marine to deploy the smartgun as a sentry gun.
While deployed the gunner will use his secondary gun.

Advanced tracking system
Increases the marines accuracy by 10 points against enemies targeted by Kill That Bastard(click on the enemy and a skull appears indicating it is activated)

High impact rounds
Increases the slow effect of the Suppressive Fire skill for the whole squad.
Default slow effect reduces alien speed to 70%.
I do not have the exact numbers, but it is significant extra slow. I would estimate that aliens move no faster than 50% speed, mabe even down to 40%.

My opinion
I think the gunner deserves a spot in every squad, the damage is too good. And the extra slowness from suppressive fire, buys the squad more time to shoot at aliens before they can get too close. For the Casual player i would reccommend 2 or even 3 gunners. For the Experienced player I think 1 or 2 gunners would do. For the Expert player it will suffice with 1 gunner, this is because even with all that extra dps, it is still not enough to kill every rushing alien in closed spaces on high difficulty.

Recon
The recons main role is stealth and movement increase

Unique attributes
Weapon training - M42A3 Sniper rifle(lvl3)
The marine can equip sniper rifle as a special weapon.
It costs 1 command point per shot
Takes 1 second to aim before shooting and is not moving while aiming the sniper.
Will stun bigger aliens for about 1 second.

Fast deployment(lvl6)
The squad movement speed is increased.
Testing shows the speed increase is about 15.5%.
Does not stack with other recon with fast deployment.
It does stack with the common perk Fast(about 3.5% extra movement per marine).
Combined if the perk Fast is also taken on every marine about 30% with a squad of four.

Infiltration tactics(lvl10)
Enemy detection time is increased by 25%

Class upgrades
Silencer
The precision shot skill no longer generates noise.
Enables killing enemies silently with the sniper.

M11 Battle scanner
Gives access to the Scanner skill, which reveals the position of all moving entities on the current sublevel.
It costs a tool to activate.

Infrared goggles
Enables the flashlight to see through walls in a 10m range.
Will highlight enemies in a green contour when on other side of walls.
Will also detect enemies that do not show up on motion tracker.

My opinion
The ability to silently kill aliens from long range without triggering a hunt or any suspicion is way overpowered. For anyone considering a stealth approach, a recon is a must. It gets even stronger at level 10 with the extra time before detected when in line of sight. For the general flow of the game, the strong speed buff is really noticable. The infrared goggles also comes in real handy when you want to know what is in the next room without opening the door. The battle scanner costs a tool to activate, and therefore is too expensive to be of any use. When the fight starts the sniper is mostly useless, because most fights have the squad moving while shooting, and the recon is very vulnerable if standing still to aim. But the stun effect may come in handy in some encounters. To get the most out of the recon it requires a bit of management and tinkering.
For the Casual player it depends on the interest for stealth, if not interested, then consider dropping the recon altogether. For the Experienced and Expert player always bring 1 recon.

Medic
The medics main role is healing, both hitpoints and stress.

Unique attributes
First aid instructor(lvl3)
Healing interaction durations reduced by 50%
This makes using a medkit take half the time to apply.
Does not stack with other medics.

Medical assistant(lvl6)
All marines not in a coma or dead heal 1 hitpoint when resting.
Stacks with other medics.

Emergancy surgeon(lvl10)
Reduces healing duration for every marine returning from a mission by 30% rounded up.

Class upgrades
Morphine
Healing a marine also reduces its stress by 30 points.
Marine needs to have lost hitpoints to be healed first.
Unknown if stacks with other medics

Combat drugs
Increases the hitpoints of every marine in the squad by 1.
Does not stack with other medics

Reanimator kit
Gives access to the Reanimation interaction.
Allows the marine to heal another marine in a coma state.

My opinion
It is somewhat hard for me to give advice on the medic. As stated earlier, I normally only get hit by aliens 1-2 times in total in a campaign. And playing on +5 alien damage makes it a gamble if there is anything left to heal after a hit is taken. But adjusted for difficulty and playstyle, I will think that the medic is very useful the more damage you sustain overall on a mission. So the Casual player should bring 1 medic or even 2 for the extra healing when resting. The Experienced player should bring 1 medic for the occasional coma healing. The Expert player should consider dropping the medic altogether.

Tecker
The teckers main role is scouting by drone and utility.

Unique attributes
Hacker(lvl3)
Grants access to the Hack interaction.
The marine has the option to unlock encrypted doors.
Costs 1 tool.
This is the same as the common perk Smart Ass.

Sentry gun overcharge(lvl6)
Grants the Sentry Gun Overcharge interaction.
Improves the damage of a sentry gun.
Costs 1 tool.

Hacker Expert(lvl10)
Ulocking encrypted doors and repairing synthetics no longer cost tools.
This applies to the whole squad.

Class upgrades
Tactical drone
The marine is followed by a drone.
Excellent to scout the whole map with while the squad hides in safety.
The drone is not targeted by the aliens.
Drone can be controlled and make noise to attract aliens and lure them into a sentry gun trap or close to the ARC.

Tactical drone welder
The drone can now weld or breach doors.
The drone will be preferred for this task, even if a marine is closer.

Battle drone
The drone now has a M39 submachine gun.
It has 48 ammo.
Reloading it costs 1 ammo clip.

My opinion
I think the main strength of the tecker is the make noise action of the drone, to clear whole rooms of sleeping aliens and lure them into a death trap while staying undetected. I can find no use for the option to weld or breach doors with the drone. And the extra submachine gun from the battle drone would be 3.3 dps if 100 accuracy, but have not tested it. But 48 ammo eats up real fast. I would only get the first drone upgrade and skip the other two. As for the unique attributes there really is not enough encrypted doors or synthetics to repair to justify a tecker based on tools, just get the common perk Smart Ass on any marine to unlock doors with a tool. The sentry gun overcharge attribute I have not tested. But the thing is that when you hunker down, and have all your sentry turrets deployed, this is the moment in game when you are safest. The unbuffed sentry turrets are already very strong. But maybe something to consider if one wanted to do a challenge run with 2 or 3 marines only in squad, then the extra damage on sentry turrets would come in handy. The Casual player should consider dropping the tecker altogether because of the micromanagement style of play. The Experienced player, if likes to tinker from a safe spot, should consider taking 1 tecker. The Expert player should consider dropping it in favor of a recon doing the same tasks, although if on the first playthrough and without map knowledge the scouting can come in handy.

Based on the classes ability and different difficulty settings I have put together three squad compositions, one for each player style. The fifth marine for later in the campaign.

Casual

• Sergeant
  
• Gunner
  
• Gunner
  
• Medic
  
• Gunner

Experienced

• Sergeant
  
• Gunner
  
• Recon
  
• Medic
  
• Tecker

Expert

• Sergeant
  
• Sergeant
  
• Gunner
  
• Recon
  
• Sergeant

Happy Gaming!

Guide on Strategy & Tactics
https://steamproxy.com/sharedfiles/filedetails/?id=3225332177


Guide to Weapons
https://steamproxy.com/sharedfiles/filedetails/?id=3214857204


Guide to Perks
https://steamproxy.com/sharedfiles/filedetails/?id=3206245408


Guide to Stealth
https://steamproxy.com/sharedfiles/filedetails/?id=3232146428


Expert Guide on stress
https://steamproxy.com/sharedfiles/filedetails/?id=3193340311


Guide for Max DPS Squad
https://steamproxy.com/sharedfiles/filedetails/?id=3216824877