This guide is currently WIP and nowhere near complete - it's also not intended to be read all at once, much like Payday 2's legendarily long guide. The purpose of this guide is to serve as a reference point for in-depth technical information on how the game's mechanics work - if you want information on a particular thing, find the relevant section. ctrl+f is your friend.

Note that this guide is written primarily around Overkill difficulty, but info on lower difficulties is included when applicable. If you're wondering what difficulty something is in reference to and it isn't specified, it's probably Overkill.

The information presented in this guide is in the process of being updated for 1.2.0. If you have any information about anything that this guide is unsure of or currently does not mention, feel free to bring it up!

This is written and worked on as a labour of love by community members who simply want to understand how the game functions; all of the information documented is discovered by a combination of independent testing, calculation, and comparing with datamined game files when applicable.

Skills in Payday 3 are built around 3 primary buffs: Edge, Grit, and Rush. Edge grants a 10% increase to damage dealt, Grit grants a 10% decrease to damage received, and Rush grants a 10% increase to movement speed. The effects of Edge, Grit, and Rush are additive with other sources, meaning the 10% damage granted by Edge combined with the 20% damage from Combat Marking would result in a total 30% damage bonus.

Many skills require an active buff to utilize them, giving them new effects or interacting with them in some way, and certain skills will allow you to gain, refresh, or consume the core buffs. You can only gain a buff from a skill if you don't have it and you can only refresh a buff if it is currently active. All three buffs will last for 20 seconds, however certain skills will consume them to activate their effects, instantly removing it.

The base damage multiplier is 1.0, but Precision Shot will overwrite this with the scope multiplier. All other damage buffs are additive - Edge adds 0.1 to this value, Combat Marking adds 0.2, Finisher adds 2.0, and so on.

The highest multiplier you can achieve would be 9.2x (6.0 from Precision Shot, 0.2 from Edge with Pain Asymbolia, 0.35 from High Grain, 0.1 from Face To Face, 2.0 from Finisher, 0.1 from Coup De Grace, 0.25 from Duck And Weave, and 0.2 from Combat Marking). Ultimately the small 10% and 20% damage bonuses don't actually add up to that much and you're better off focusing on just a few of them to hit breakpoints that match your weapon and play style.

The headshot damage multiplier is applied multiplicatively and does not add to the standard damage multiplier.

For easy calculation of breakpoints you can use the Payday 3 Weapon Bench.[puppy-girl.github.io]

The base damage reduction is 0 and Grit adds 0.1 to this value, which is additive with other sources of damage reduction. For example, Threat Assessment will add 0.2 to your damage reduction for a total of 30%.

The damage reduction granted by armors is applied multiplicatively with other sources, meaning a 25% damage reduction from armor will multiply with a 10% damage reduction from Grit to reduce armor damage by 32.5%.

All armors in the game currently operate in a similar way with the main differences being number of downs, number of chunks, regen time, movement speed, damage reduction, and trauma scale. For more information on movement speed check the dedicated section.


All chunks can take 75 damage regardless of the armor type, however the non-adaptive armors have a 25% damage reduction for an effective total of 100 damage per chunk while the adaptive armor has a 5% damage reduction for an effective total of 78.95 damage per chunk.

The damage reduction from Grit (and other sources of damage reduction) is applied multiplicatively to the inherent damage reduction that armors have, meaning that the effective total is ~111 damage per chunk with non-adaptive armor and Grit. In practice this amounts to being able to take one extra shot from most enemies on Overkill. Against dozers you will only be able to take 3 shots both with and without Grit.

Upon taking damage the armor bar will begin flashing red, indicating the armor that you can recover by waiting out the regen time. For non-adaptive armors, 35% of all damage taken is permanent and cannot be recovered - this is called trauma.

Individual chunks cannot armor gate, but the final chunk can. This means that any excess damage dealt to your last chunk will not be applied to health, it will simply disappear. If you have 10 armor left and take 50 damage, your armor will break and the remaining 27.5 damage (reduced from 50 to 37.5 due to the 25% damage reduction) will be ignored. Enemy snipers in this game follow armor gating rules unlike in Payday 2.

The lighter armors are incredibly viable due to their shorter regen times, providing a play style closer to previous Payday games. There is less of a point investment required to make them work and the faster movement speed allows you to play more aggressively, giving you more build flexibility than if you were to play with Heavy Ballistic Lining.

The maximum HP value without skills is 100, however this is a little misleading due to a hidden damage reduction mechanic. When HP drops below 30 all damage beyond that point is halved; this means that the last 30 HP is effectively 60 HP, being worth almost the entire health bar up until that point. The existence of this hidden damage reduction means that your effective health is 130 rather than 100.

It's worth noting that this damage reduction is guaranteed to occur, even if you are above 30 HP when taking damage - if you have 40 health and take 20 damage you will lose 10 HP as expected (30 HP remaining) but the leftover 10 damage is halved because you are now at 30 HP, so instead of 20 damage you take 15. To put it another way you can be at 100 HP, take 100 damage in a single hit, and survive with 15 HP remaining (100 - 70 = 30 HP; the remaining 30 damage is halved to 15; 30 - 15 = 15).

Fortitude Basic increases your max health by 50, from 100 to 150. The 30 HP damage reduction still applies, meaning you have an effective 180 HP. With the Unyielding skill you gain an additional 15 max HP for each down you have. With Fortitude Aced this means your HP can go as high as 225 (255 when factoring in the 30 HP damage reduction).

When healing above max HP you gain adrenaline - this is displayed over your health bar and your max adrenaline is equal to your max HP. If you have 165 max HP you will only be able to store up to 165 adrenaline. You lose adrenaline at a rate of 1 point every 2 seconds, though this can be slowed or completely halted with Walking Tall. Upon taking damage this degradation is paused for 6 seconds.

Damage to adrenaline is applied before damage to armor. Adrenaline cannot damage gate - that is to say, any excess damage dealt to adrenaline will always be applied to the next resource in queue (armor or health). Damage that bleeds from adrenaline to health appears to have some kind of damage reduction applied, but more testing needs to be done.

When you are revived you always get up with 50 HP, no matter how high your max health is.

Fall damage ignores damage reduction and always deals full damage. The minimum fall damage you can take is 10% of your max health after falling 3.8m, but it begins to scale up fast - after falling 4.8m the damage jumps to 30% then gradually increases up to 50% at 6m. Between 6m and 7m the damage doesn't change, but past 7m it jumps to 110% guaranteeing that you die unless you have adrenaline. Fall damage is first applied to adrenaline, so having at least 11% adrenaline will allow you to survive a lethal fall from full health.

The player camera is 1.58m tall when standing, however player pings are 0.5m off from the actual distance shown. The first 2m of ping distance is visually wrong and represents 1.5m instead, so 2m is 1.5m and 3m is 2.5m. If you want to approximate how much fall damage you will take using a ping you must subtract 2m from the ping distance.

The base movement speed multiplier is 1.0 and Rush adds 0.1 to this value, which is additive with other speed improvements. Movement speed is capped, however the cap depends on your current weight tier and stance (sprinting, walking, or crouching).

Buffs can only increase your speed by up to 1.5m/s while sprinting, 0.5m/s while walking, or 0.25m/s while crouched. Going beyond these values does nothing.

This means the 10% bonus from Rush is enough to max out your movement speed while crouched. The bonus needed to reach max walking speed depends on your weight tier; at weight tier 1 you need the 20% bonus from Pain Asymbolia in the Fortitude skill line, but higher weight tiers only need 10% Rush. To max out sprint speed you need the 20% bonus from Pain Asymbolia and the extra 10% bonus from Swift; this applies to all weight tiers.

Increasing movement speed past 30% currently has no benefit.

Player speed is divided into four weight tiers, where each tier moves slightly slower than the last. There are currently two things that affect your weight tier: equipped armor and carried bags.


When you pick up a bag it will increase your weight tier by 1, 2, or 3. How many tiers your weight is increased by depend on the bag you pick up. Most bags only increase your weight tier by 1, with the following exceptions:

+2: big money, gold, rare minerals, zipline bags
+3: RTC cage parts, G&S drill parts, NRFTW thermite rig, meth ingredients
+20: carrying two bags with Power Lifter

An interesting observation is that dyed money has a lower modifier than full money bags, meaning you move faster if you let the dye packs go off in No Rest for the Wicked and you don't have Beast of Burden.

If you are already at weight tier 4 then you cannot move any slower. This means the 4 chunk armor (Heavy Ballistic Lining) is less affected by speed penalties than any other armor type, as it starts at tier 3.

Despite the game saying that Standard Lining is faster than Adaptive Armor Lining and Light Ballistic Lining, all three armors move at the same speed (tier 1).

Sentries are somewhat straightforward on the surface but have some nuance to how they work and how the skills interact with each other.

Sentries deal a base 15 damage per shot with an AP of 0.5 and fire in bursts of 14 - this means they deal 210 damage per burst, however due to their low AP value they must break enemy armor to actually kill. Their damage is set in such a way that they cannot kill a single light SWAT before they finish a burst - it will always take one burst and one extra bullet to kill. The AP Turret skill allows them to kill light SWAT in around half a burst instead.

How sentries fire bursts can be somewhat manipulated by using the mastery skill to manually mark the sentry target. When a sentry changes its active target the burst is reset, allowing it to immediately start firing a new burst. If the sentry finishes a full burst then you must wait for it to start a new burst for this to happen again. [This paragraph is speculation. Confirm it?]

Against regular police officers and security guards they will always aim for the head and kill in one shot. Against every other enemy they will aim for the chest. They have unique tracking for shields where they will try to aim at the shield window and break it before killing the shield through it - this has issues however when the sentry is to the left or right of the shield and not directly in front of it, as it can over aim and shoot too high to hit the shield and miss.

Sentry skills describe "heat", but this can be simplified to health. Sentries have 250 base health and every time they shoot they decrease their own HP by 2, meaning they can fire a total of 125 shots before breaking without skills. After a sentry breaks you can pick it up and redeploy it, fully repaired. Picking up a broken sentry takes 2.5 seconds as opposed to the 1 second of an unbroken sentry.

Engineer Basic and Aced simply multiply the sentry base HP by 1.2 and 1.4 respectively. Cooling System is somewhat misleading in its description and may be bugged, as it says that it decreases heat buildup on sentries by 30% from damage. The issue lies in the fact that sentries damage themselves when they shoot, which means this skill decreases the 2 damage sentries deal to themselves to just 1.4. If you're making a build where you want maximum up-time on sentries, Cooling System is absolutely required.

The Cooling System interaction also extends to the Dual Sentries skill which multiplies self-damage by 1.5. Because Cooling System is already multiplying self-damage by 0.7, these two skills end up cancelling each other out and change the self-damage multiplier to just 1.05 - only slightly higher than if you had neither skill.

The frag grenade, flashbang, and smoke grenade alert everyone within a 50m radius when they detonate. Without skills you start with 3 grenades (any type) or 2 throwing knives. Throwables do not receive damage bonuses from skills unless the skill states otherwise.

3 seconds after pressing the throwable button the grenade will detonate, dealing [150 / 125 / 100] damage up to [2.5 / 4 / 8] meters away with an AP value of 2. [Needs a rewrite, add more info.]

3 seconds after being thrown the flashbang will detonate, affecting all NPCs within 8m (9.6m with Tactician Aced). The blind effect lasts 4 seconds (4.8 with Scramble), during this time civilians are unable to follow you and all NPCs are immobilised with the only exception being the dozer. Blinding cloakers is potentially dangerous as they will begin flailing, dealing 90 health damage every second to any players standing near them. The damage they deal when flailing does not change with difficulty.

Currently throwing knives are the main throwable for stealth as they can be used as remote lures. When a knife hits a surface it will emit a sound that can be heard by any guards within 15m; one guard within range will move to investigate the point of impact. The guard that is picked is a little inconsistent and can often not be the guard you expect. If you have Retriever then the guard can see the knife and will call a search - you can stop this by picking up the knife before he begins calling. If you are already in search there is no penalty to leaving throwing knives in the open.

With Blade Bouncer each knife impact can lure a different guard, potentially luring up to 3 guards at once. This can potentially be useful but due to how hard it is to predict the path of Blade Bouncer it can often have undesirable or unexpected results. If a single guard is alerted by multiple bounces of Blade Bouncer they will investigate the sounds in reverse order, from the last bounce they heard to the first bounce.

If you have both Retriever/Blade Bouncer and the knife bounces within range of a guard they will immediately begin calling in a search, even if the knife immediately bounces past the guard. It only needs to pass through his call radius once for this to happen. You can stop the guard calling by picking up the knife, but depending on how the knife bounced it may not be possible to do in time.

When a knife hits someone it deals 150 damage with 1.5 AP - this allows it to one shot SWAT and specials but not shields. Throwing knives also have a 2x headshot multiplier, though this is pretty insignificant and doesn't change how they function in any meaningful way.

Throwing knives can penetrate and kill one additional target, however this is pretty hard to force to happen as they become stuck in the first person they hit. There seems to be a short amount of time after a knife kills someone where the damage hitbox is still active, and if the corpse passes through another NPC during this time it will deal damage to the second NPC (killing them if they are not a shield or bulldozer). Only one extra target can be killed this way.

With Blade Bouncer you can deal enough damage to one shot a shield (requires one bounce, doesn't need to be a headshot). You can never deal enough damage to break the dozer visor, even with two bounces - it only deals 750 damage, 100 less than is needed.

2.5 seconds after throwing a smoke it will detonate, creating a smoke cloud. The cloud is created at the position the smoke grenade detonates, and does not follow the physical position of the smoke grenade. Over the next 12 seconds the cloud will expand outwards to a maximum width of 10m and height of 8m. If the smoke is against a wall, it will only expand 5m away from the wall - half of the total volume is lost. After 12 seconds have passed it will dissipate over the next 2 seconds for a total duration of 14 seconds. The effects of the smoke are still active until it fully clears.

The way the cloud propagates makes it a little inconsistent, and the size can vary slightly - generally smoke clouds are 8m or 9m wide for most of their life and hit max size just before they start dissipating, even with Tactician Aced.

While the in-game description states that enemies must be in the smoke for their accuracy to be reduced, this isn't true. As long as the smoke breaks line of sight between you and the enemy it will multiply their accuracy by 0.3 (70% reduction), making it an absolute life saver in certain situations. The way the penalty is applied means you don't have to think too much about how you're using it, as throwing a smoke at a choke point will make all enemies firing through it less accurate. You can also throw it at an objective to make interacting with it significantly safer, or simply throw a smoke at your feet to make all enemies less likely to hit.

The description also states that enemies move slower in the smoke, however this seems to either not work or the effect is so small as to be unnoticeable. There is one enemy where this effect is incredibly noticeable however, being cloakers; if a charging cloaker enters a smoke cloud it will stop charging and begin slowly walking until it exits the cloud. This gives you plenty of time to kill the cloaker with complete safety.

1.5 seconds after pressing the throwable button the shock grenade detonates at its current location, stunning all enemies within 3m. Each stunned enemy can trigger an arc which will jump to a character (even your own teammates, though it will not stun them) and then chain again. Each arc chain can jump to up to 7 characters, and will not target characters that are already part of an active chain. All enemies that get hit are stunned for 1 second on each detonation. After the stun expires they are stuck in a recover animation for around half a second. The grenade will detonate two more times with the same 1.5s delay for a total of three detonations, stunning enemies within the detonation radius for a total of 4.5 seconds. [Confirm some of the numbers here!]

If you are within range of the grenade when it detonates it will stun you, triggering Code Blue on any teammates that have it. The stun lasts less time for you than it does for enemies, but it can arc to you from enemies and, annoyingly, teammates.

Any shields, tasers, or techies hit by the stun will instantly die. Specials killed by the stun will remain in the stun animation until the animation completes, at which point they will fall to the ground normally. When killed this way their bodies are intangible and will not block bullets.

The arcing and special killing attributes of the shock grenade give it distinct differences from the flashbang in usage, as it can theoretically extend further than the flashbang and affect enemies around walls, but you lose the ability to grab human shields - as such the choice is ultimately a matter of play style and build.

The radius of the shock grenade can be extended with Tactician Aced and Demolitionist Basic for a total 40% increase.

Tools are non-renewable and once placed cannot be picked back up without the Full Recall skill. They can stick to NPCs and most surfaces (there are placement issues in certain areas) allowing for some flexibility in how you use them.

You spawn with 2 cameras (3 with Extra Pockets). When activated you will pull out your phone and view the camera feed, functioning the same as normal cameras but without access to runtimes. You cannot cycle from a microcam feed to a security camera feed - they run on separate loops. Taking damage will force you to exit the microcam.

When aiming at the bottom of a door the microcam snaps to the other side. This allows you to place microcams through closed and locked doors, which can be useful on Gold & Sharke to help quickly find the correct room that contains the red keycard.

You can pick up a microcam at any time.

You spawn with 5 mines (8 with Extra Pockets). When activated all placed mines will simultaneously detonate, stunning everyone in a 5m radius for 6 seconds. Unlike other forms of stun, infrasonic mines do not require line of sight and can affect NPCs through walls.

Infrasonic mines do not proc Tactician Basic and do not benefit from Scramble. You can pick them back up at any time as long as you don't detonate them.

Needs filling out (Sarah will do)

You spawn with 2 sensors (3 with Extra Pockets). After being placed the sensor can mark 15 NPCs within a 5m radius before it stops working - anything within its radius is permanently marked and will remain marked even after the sensor stops working. If an NPC exits the radius, the mark is immediately removed and it will consume another charge to mark the same NPC again. This means NPCs on the edge of its radius can very quickly consume multiple charges by repeatedly entering and exiting the sensor area.

If you place the sensor directly on an NPC they will remain permanently marked as they never exit the radius.

Dozers that enter the radius are never unmarked, even if they leave the radius.

Motion sensors can only be picked back up if they haven't marked anyone yet.

While an enemy has any amount of armor any damage they take will be dealt to armor instead of health. If a shot were to deal more damage than the enemy has remaining armor the additional damage has no effect, meaning that, regardless of the damage stats of the weapon, all shots will deal 1 damage if an enemy has 1 armor left. While damage modifiers, such as Edge, do affect damage to armor, headshot multipliers do not.

In addition to damage to armor, weapons with armor penetration (AP) can also deal damage to health, dependent on the weapon's armor penetration stat and the enemy's armor hardness stat. While headshots do not affect damage against armor, headshot multipliers do still affect penetrating damage to health—low AP weapons gain no benefit from headshots against armor but weapons with more AP can still deal additional damage. To calculate effective armor penetration against an enemy you can use the following formula:


For each shot against an enemy you will both: reduce their armor according to your weapon's damage and any active damage buffs, and; reduce their health by your weapon's damage multiplied by damage buffs, headshot multiplier, and your effective armor penetration. Regardless of the armor stats of an enemy, a high AP stat and landing headshots may allow a weapon to reduce an enemy's health to zero before their armor breaks.

Protective objects carried by enemies—such as the shield unit's shield and attached visor—have their own armor hardness stat, however armor penetration works differently with these objects compared to an enemy's armor. Alongside damage dealt to the object, if your effective armor penetration is greater than 0 your shot will be allowed to pass through the object unobstructed. Rounds that penetrate an object will deal full damage as if the object wasn't there.

An easy way to tell if your weapon's AP can breach an object is to compare it to the armor hardness stat reduced by 1. For example: Shield objects have an armor hardness of 3. While the R900S' base armor penetration of 2 is not enough to penetrate the shield, increasing it to with High Grain will allow the bullet to pass through and hit the shield unit.

Unfortunately there isn't much to say here, as we don't really understand how most weapon stats work. All weapon mods give positive or negative modifiers to certain weapon stats (note that +Recoil means it makes recoil easier to control, not harder).

The current issue with these stats is that they are not directly comparable. For example, pre 1.1.4 Cutting Shot used the same weapon stat modifier system as the weapon mods by adding +30 to AP for all weapons - in practice this was a +0.5 increase in AP. The AP stat scales from -100 to 100, with 0 being no change and 1 being +0.1. 100 is +1.0. It increases linearly in steps of different sizes - that is to say, the lower values (+1, +2, +3, and so on) are worth more than the higher values (+80, +81, +82, and so on).
This graph shows how AP is affected by the AP stat (previously used by Cutting Shot).

We can extrapolate from this that all weapon stats use a similar system where a lower total has a bigger effect than a higher total, but since we don't know the exact way that weapon stats are changed by their stat modifiers and it's likely to be an arbitrary scale for each stat it's ultimately impossible to say what +5 Recoil and +5 Spread mean.

If you didn't understand any of that, the main takeaway is that weapon mod values are somewhat meaningless. You can use the values to get an approximate idea of what they will do to the weapon, but that still won't give you a proper picture of how it will affect the weapon - the best thing you can do is equip the mod and see how it feels. If you really don't care about any of this, just equip your weapon with whatever looks good. You'll have a similar experience, but if you notice that the gun feels bad in a certain way it may be the result of your weapon mods.

Enemies follow similar rules to players, having both health and armor. Enemy armor has a hardness value that dictates how much damage is allowed to pass through into health. For more information on hardness and armor penetration check the dedicated section.

Enemies have an accuracy stat that dictates how likely they are to hit - a value of 0.0 means they will never hit but a value of 1.0 does not mean they will always hit; there is a very small chance that enemies will still miss with 1.0 accuracy, but for simplicity sake you can think of it as being a scale between 0% and 100% accuracy.

Enemy accuracy and damage drop off with distance, so the values given here are not an accurate portrayal of how enemies perform as you start to move away; they are a good baseline for comparisons and are representative of close range encounters.

Enemy health and armor values do not change with difficulty. The only thing that changes is damage and accuracy. Enemy weapon stats are formatted in the following way:
[Normal/Hard/V. Hard/OVK]

Guards are active when the map first loads and will become civilians after first responders arrive. They have 100 HP with no armor and deal [4/4/6/10] damage with an accuracy of [0.6/0.7/0.8/0.9]. They can fire up to 8 shots per second for a max DPS of [32/32/48/80], though in practice they do not fire this fast.

First responders start spawning after the alarm and arrive during the first negotiation phase - after their arrival no more first responders will spawn. They have 100 HP with no armor and deal [2/2/3/5] damage with an accuracy of [0.3/0.4/0.5/0.6]. They can fire up to 13 shots per second for a max DPS of [26/26/39/65].

Light SWAT start spawning after the first negotiation phase ends. They have 70 armor with 1.5 hardness and 150 HP. There are three variations of light SWAT:


Shotgunners will swap from their shotgun to a pistol when in the presence of hostages, however this can be a little inconsistent. Sometimes they will swap to their pistol when no hostages are nearby, and sometimes they they will pull out a shotgun in the presence of hostages. Their pistol has the same damage and accuracy stats as security guards.

Heavy SWAT replace light SWAT when dozers become active. They have 170 armor with 1.5 hardness and 150 HP. There are three variations of heavy SWAT:


Shields are considered "uncommon"; while they are special enemies, up to two shield units can be active at a time instead of just one. They have 180 armor with 2.0 hardness and 160 HP.

The physical shield has a hardness of 3.0, making most weapons unable to penetrate it; exceptions to this are the Red Fox or R900S/Bullkick 500 with High Grain active which allow you to shoot directly through the shield. Unlike previous games, the shield has a visor that can be shot through to kill the shield head-on: the visor has 250 HP and a hardness of 1.75, meaning you need more than 0.75 AP to be able to penetrate the visor - this allows you to deal full damage. Weapons with 0.75 AP or less need to break the visor first which effectively doubles the shots to kill for most weapons (though it can vary a little from weapon to weapon; generally the shots to break the visor is the same as the shots to kill the shield).

Standing too close to a shield unit will cause it to bash. The bash stuns any player it hits and has a cooldown of 3.5 seconds, and can (frustratingly) stun players standing behind the shield.

Shields have a pistol that they will shoot you with. Their pistol is a lot more powerful than the normal pistol that enemies use, dealing [6/6/8/20] damage with an accuracy of [0.8/0.9/1.0/1.0]. They can fire up to 8 shots per second for a max DPS of [48/48/64/160], though in practice they do not fire this fast.

Snipers are considered "uncommon"; while they are special enemies, up to two snipers can be active at a time instead of just one. They have 40 HP with no armor.

Upon spotting a player they will begin aiming - after 5 seconds have passed they will shoot, dealing [100/100/200/400] damage. They have an accuracy of 1.0 on all difficulties.

Snipers can shoot you through human shields.

If you get too close to a sniper they will swap to a pistol, using the same damage and accuracy stats as security guards.

Only 3 specials can be active on the map at once, and only one of each special can be active at any given time.

Called "zappers" in-game but for legacy reasons they will be referred to as tasers in this guide.
Tasers spawn from the beginning of the heist. They have 140 armor with 1.5 hardness and 150 HP.

Naders begin spawning after assault progress hits 0.33. They have 140 armor with 1.5 hardness and 150 HP.

Cloakers begin spawning after assault progress hits 0.66. They have 150 HP with no armor.

Cloakers spawn from special vents on the ceiling and drop down. Vents that they have spawned through will explode from the ceiling, indicating where they are coming from.

After spawning, cloakers will begin sneaking around the map to close the gap on a player. Once they get close enough they will begin charging, indicated by their iconic sound. In this state they will only stop chasing if they are stunned, killed, or the player stands in a spot that the cloaker cannot reach. If they reach the player they will subdue them and begin dealing [2/4/6/15] health damage every second, completely ignoring armor. This damage ignores the 30 HP damage reduction.

When not charging they can shoot you with an SMG dealing [2/2/4/8] damage with an accuracy of [0.55/0.65/0.75/0.95].

Blinding a cloaker with a flashbang is potentially dangerous as it will cause them to begin flailing, dealing 90 health damage per hit on all difficulties for a total of five hits (before 1.1.3 this was 15 damage - it's currently unknown if dealing 6x damage is intended behaviour). This damage ignores the 30 HP damage reduction. Each of the five hits has a different delay. Being hit will stun you for around 1 second, giving you a very brief window to escape after the first hit. If you get hit by the second or third hits you cannot escape until the fourth hit, which you have approximately 0.2 seconds to escape from. The best way to escape would be to hold sprint and try to run away from the cloaker, otherwise you can try to kill them.

Techies begin spawning after assault progress hits 0.66. They have 140 armor with 1.5 hardness and 150 HP.

Dozers begin spawning after assault progress hits 1.0. They have 3500 armor with 4.0 hardness and 200 HP, however their visor only has 850 armor. Destroying the visor reveals their face, allowing you to headshot them. The visor cannot be penetrated by any means - it absorbs all damage taken. Dozers are immune to all forms of stun and stagger.

If you get too close to a dozer they will try to kick you, dealing 900 damage on Overkill (before 1.1.3 this was 150 damage - it's currently unknown if dealing 6x damage is intended behaviour). The same damage is also applied if you get hit by a dozer's charge.

In the presence of civilians dozers will try to avoid shooting.

300 HP.

All the information in this section should be taken with a grain of salt - it still needs verifying and may be wrong. How drama works also needs to be documented.

Assault progress is a core mechanic of how assaults and loud gameplay work. It is a value that goes from 0.0 to 1.0 and is increased by completing objectives. The higher this value, the harder assaults become:

0.0 - only tasers can spawn and the wait phase lasts 40 seconds.
0.33 - naders can spawn.
0.5 - the wait phase is reduced to 30 seconds.
0.66 - cloakers and techies can spawn, assault length increases.
1.0 - dozers can spawn, light SWAT are replaced by heavies, wait phase lasts 20 seconds.

On Overkill the assault progress can update in real time, however on lower difficulties the assault progress only updates between assaults. For example, entering the vault on NRFTW will set assault progress to 1.0 - on Overkill, heavies and dozers will begin spawning instantly. On lower difficulties heavies and dozers will not begin spawning until the next assault begins.

Assaults are broken into five phases:

Indicated by the text "assault incoming". During this phase cops can begin spawning [can they?] and moving around, but you won't see many of them until the assault actually begins. This phase always lasts 20 seconds.

Specials and snipers cannot spawn during the first build up, but shields can spawn.

Unknown.

The length of the wait phase depends on assault progress. At the start of the heist this phase lasts 40 seconds. At 0.5 assault progress (after naders start spawning but before cloakers start spawning) this is reduced to 30 seconds, and after dozers/heavies start spawning this phase only lasts 20 seconds.

Indicated by the text "police assault". During this phase cops will spawn whenever possible and will advance on the players.

The length of sustain depends on assault progress and the difficulty you are playing on; on normal this phase will last 90 seconds but will increase to 2 minutes after cloakers begin spawning. On difficulties above normal, this phase will last 2 minutes and will increase to 3 minutes after cloakers begin spawning.

After sustain ends the assault will continue for as long as you are in fade. The exact criteria for the assault to end after entering this phase is still unknown.

Indicated by the text "police regrouping". This phase lasts around a minute but the exact length depends on heist. This phase is extended by 1 second for each hostage you trade; after trading 10 hostages each hostage is only worth half a second instead. Manipulator skills do not extend the time gain from trading. During this phase traded hostages will alternate between dropping FAKs and ARKs.

Any enemies that are active on the map will run away. If they get far enough away they will despawn, but if they are still in the map when the next assault begins they will return. This is especially noticeable with dozers who move so slowly that they will often not escape before the next build up, allowing you to make use of any damage you dealt to their visor before the assault ended.

When the alarm goes off the game will enter a unique initial negotiation phase. During initial negotiations hostages do not generate resources but will extend the negotiation timer by 15 seconds upon trading a certain number of civilians. You can only trade hostages when the negotiation timer is below one minute. Each heist has a different threshold for how many hostages need trading to extend the timer. Initial negotiations are immediately ended when you walk through certain areas, complete certain objectives, or create an alert sound (gunshot, explosion, etc).

Once this phase ends a build up will start.

There are four types of stun and stagger in the game that all work in slightly different ways.

Electrical stun is triggered by detonating cameras with Hacker Aced (6 seconds), shooting a Taser battery (6 seconds), shooting a Taser mine (3 seconds), Kinetic Short Circuit (5 seconds), and shock grenades (1 second). They will be stuck in a stunned animation with an electricity effect surrounding them until the animation ends, at which point they will start acting normally again after a brief recovery animation. Enemies stunned this way cannot be grabbed as human shields.

Detonating cameras with Hacker Aced currently does not trigger Tactician skills.

The infrasonic mine functioned like electrical stun prior to 1.1.3 but now falls into its own category for one simple reason: it is the only stun type other than camera detonation to not benefit from Tactician skills. Enemies stunned this way cannot be grabbed as human shields.

Blind stun is triggered by flashbangs and lasts 4 seconds, during which time all affected enemies are completely immobilised. The duration can be extended through skills. While blind, non-special enemies can be grabbed as human shields - they are not counted as civilians or hostages and will pull out a weapon to shoot you after being shoved away. You can perform takedowns on enemies grabbed this way.

If a civilian is tied up and then blinded you cannot command them to follow you until the stun ends.

This is triggered randomly when dealing damage to an enemy [higher chance when they have no armor?], or by melee. Melee has a 5 second cooldown - after meleeing an enemy you cannot melee another enemy until 5 seconds has passed. While staggered they will play an animation where they stumble slightly. The animation lasts around one second. Enemies staggered this way cannot be taken as human shields.

This is triggered randomly when dealing damage to an enemy or by Shock & Awe, Heavy Hipfire, Suppressive Fire, and Slide Tackle [anything else?]. Heavy stagger is represented by an animation where the enemy stumbles to the ground and tries to regain their footing, which takes around three seconds. Enemies staggered this way cannot be taken as human shields.

The Medic skill line is based around reviving teammates and improving medic bags.

"If you have GRIT, successfully reviving your teammate will give both you and that teammate damage immunity for 5 seconds."

When combined with Medic Aced and Code Blue this skill can be incredibly powerful. 5 seconds is enough to regen Standard Lining/Adaptive Armor Lining, negating some or all of the damage you take during the revive. Additionally the damage immunity you gain makes you immune to all forms of stun from either dozers or shields, making it an incredibly safe way to double team a dozer if someone goes down to one.

The immunity does not have a buff icon, so you will only know if someone has this skill if you ask or if you pay attention to the damage that you both take after being revived.

"Whenever a teammate is downed or disabled, you gain or refresh RUSH.
As long as you have RUSH, you pick teammates up 30% faster."

With this skill you gain Rush whenever a teammate is incapacitated by any means, including taser mines or the self-stun of shock grenades.

The Ammo Specialist skill line is based around picking up ammo and improving ammo bags.

"Your reserve ammo capacity is increased by 20%.
Ammo bags you deploy have 2 additional charges."

The reserve ammo bonus does not apply to starting ammo.

"Whenever you pick up ammo, if your current weapon's magazine is full, you gain EDGE if you don't have it."

This does not apply to ammo obtained from ammo bags - the ammo must be obtained from an ammo drop.

"As long as you have GRIT, ammo drops will instantly regenerate your current armor chunk.
This effect cannot occur more than once every 2 seconds."

One of the stronger skills, especially with armors that have a long regen time. By combining this with Combat Reload for infinite Grit/Edge as well as Replenish to instantly pick up ammo from enemies you kill it enables a playstyle similar to Bullseye from Payday 2, allowing you to recover armor after killing an enemy every 2 seconds.

"All placed Ammo Bags increase armor penetration for 30 seconds after interaction for you and all your teammates. Each additional crew member equipped with this skill increases weapon damage by 5% on top of that."

The effects of High Grain apply to every ammo bag, not just ammo bags placed by the person with the skill. The effect does not refresh, so for optimal usage you want to wait until the 30 seconds have expired before using an ammo bag again. The effect is triggered on everyone even if you do not have the skill - as long as one person in the lobby is running High Grain everyone will receive the buff.

The AP increase is +0.2 - this allows the B-9 and PC9 to penetrate shield windows, the R900S to penetrate shields directly, and allows the AK/CAR-4 to deal health damage to shields.

The stacking +5% damage only applies if multiple people have the skill - if only one person has this skill you will only receive the +0.2 AP.

The Signature 40/403, Stryk, Reinfeld 880, and FSA receive no benefit from the AP increase.

The Infiltrator skill line is based around stealth and throwing knives.

"Whenever you successfully pick a lock, kill an enemy with a throwing knife, or pick up loose cash, gain or refresh RUSH."

In combination with Transporter Basic and Bagger you can more optimally bag loot - pick up one piece of loose cash, pick up two bags, drop them both, pick up another piece of loose cash, and repeat.

The Rush on throwing knife kills is also a very effective way of maintaining permanent Rush with throwing knife builds, though it requires you to have throwing knives equipped in the first place.

"Whenever a guard begins to detect you, gain RUSH."

Very simple, but in stealth this gives a very easy method of gaining Rush for Quick Fingers. Simply walk into a guard's line of sight for a split second and you don't need to waste time picking locks on certain heists (like UTS).

"As long as you have RUSH, a successful lockpick jiggle will immediately pick the lock."

Picking a lock in this way activates Infiltrator Basic, refreshing Rush and allowing you to keep picking locks instantly.

"Your throwing knives won't break on impact with the environment."

Throwing knives never break on impact with enemies so this only affects misses - it can be a huge help if you're planning on using throwing knives regularly, otherwise you don't necessarily need it. You can restore throwing knives from ammo bags as an alternative.

Throwing knives that exit the playable space are unretrievable, so you probably still want another source of throwing knives anyway (or be careful about where you throw them).

"As long as you have RUSH, you bag loot 50% faster."

As nice as this skill feels to use it is incredibly situational. Primarily a speedrun skill and may help on certain heists (NRFTW loud, Road Rage) so that you spend less time bagging loot in a dangerous spot.

Note that the bonus speed only applies when bagging loot - when picking up a bag from the ground this skill has no effect.

"Your throwing knives will ricochet off the environment up to two times. The throwing knife will do extra damage for each bounce."

The angle of the outward bounce is equal to the angle of impact - think of the way a ray of light bounces off a mirror.
The knife does lose a small amount of distance on each bounce but this loss is marginal, each bounce can travel roughly the same distance as if you were to throw the knife yourself. The knife is also affected by gravity and is very slowly pulled to the ground, but this is often so subtle that it doesn't end up mattering in any significant way. The main thing to keep in mind is your angle when throwing the knife, as extreme angles are very unpredictable - for more predictable bounces you want to throw the knife as perpendicularly as possible.

Each bounce increases damage by 200%, going from 1x damage to 3x damage and finally 5x damage. While this might sound strong the only real use is for killing shields, as a single bounce deals enough damage to one shot them. Knives don't have enough AP to do anything against dozers and the 5x bounce damage is not enough to break their visors (assuming you're somehow able to make it hit).

The real benefit of the bounce is that it can often turn a missed knife into a hit, as it will rebound and kill someone that you didn't intend; sometimes this can work against you however and the knife will simply fly away never to be seen again. While Retriever has a slight issue with losing knives, Blade Bouncer can amplify that 10 fold - having another way to recover throwables is highly recommended.

You can also make use of the bounce to hit enemies around corners without ever exposing yourself, but this takes some degree of practice and familiarity with how the bounce works and the map layout to pull off effectively or consistently. Marking enemies can help you.

Ultimately while this skill makes throwing knives a lot more fun you are still giving up the utility of smoke grenades, flashbangs, and shock grenades so it's not particularly useful or practical.

The Tank skill line is based around armor and survivability.

"If damage would normally down you, you can instead consume available GRIT to stay on your feet and become immune to damage for 4 seconds, plus an additional 2 seconds for each crewmate that’s downed or in custody.
After this effect has been applied, you can't gain GRIT until you heal using a Medic Bag or First Aid Kit, or until you're downed."

Last Man Standing (LMS) is a skill that can either be incredibly powerful and save the heist or a skill that doesn't work at all and makes you regret picking it. There is an oversight in how the skill works while down; if you are down and somehow gain Grit (Enforcer Basic, Tank Aced, Cooker) the game will recognise that you have no health upon taking any damage and will consume Grit to activate LMS - this isn't helpful because you are already down, but the bigger issue lies in the reset trigger.

LMS is only reset when you go down, however in this scenario you are already down when it activates - this means it doesn't reset when you get back up so you are unable to gain Grit until you either go down again or heal. Because you can't gain Grit you also can't trigger LMS, meaning the skill can prevent itself from working.

The Sharpshooter skill line is based around ADS with a boost for scoped weapons.

"As long as you have EDGE and are aiming down sights, distance penalties do not apply to headshot multipliers."

Long Shot means that you always use the highest headshot damage multiplier no matter what distance you are at - with certain weapon types this can be a huge boost to damage at range though other weapon types will see barely any change.

The benefit of Long Shot is heist specific, as some heists have a lot of long angles while others are very compact. Your play style will also affect how useful this skill is, as it only helps when shooting at range.

Because you need to be in ADS to use this skill it has no benefit for hipfire builds.

"As long as you have EDGE and are aiming down a scope, your shot will deal extra damage based on your scope magnification."

Precision Shot only applies to weapon mods that are classed as scopes - in the current version of the game only two weapons have scopes, being the SA A144 and the R900S. If you are using any other weapon then this skill will do nothing, and it will only apply to the SA A144 and the R900S if you are using the Fluted Marksman Scope, the Primed Marksman Scope, or the R900S' default scope (5x).

"As long as you have EDGE and are aiming down a scope, your shots will penetrate through 1 additional target."

"Increase your ADS and scope speed."

This adds 20 to your scope speed stat which amounts to a 0.125s increase in speed (assuming no weapon mods are attached).

The Escapist skill line is based around movement.

"If you have EDGE available and vault or mantle, it's consumed, and you gain or refresh GRIT"

This is a bit of a sleeper skill in that it doesn't seem particularly useful at first glance and may even seem detrimental to a lot of builds, but there are some builds that Move & Cover is excellent for - primarily Gunslinger builds. You can change weapon to gain Edge then mantle something to convert it into Grit, then change weapon again to regain Edge. In most maps there are countless places to safely do this, giving you a completely free and non-resource dependent way of maintaining Grit.

"As long as you have EDGE, GRIT, or RUSH, you can sprint through locked doors to breach them.
Only effective on doors with locks that can be picked or shot"

The last line may be a little confusing, but you can use this skill on any swinging lockpickable door even if the door cannot be shot open. Doors opened this way have their handles broken and cannot be closed, and guards are able to see the door and will call a search.

Despite the description explicitly saying "sprint", you can also slide into a locked door for the same effect.

The Manipulator skill line is based around hostages and improving the effects of trading them.

"You can shout at guards, SWAT or Heavy SWAT within 5 meters of you to force them to surrender. As long as you're aiming at them, they will go down on their knees and drop their weapon. Any damage dealt to them or taking your aim off of them interrupts this process.
Once fully surrendered, the SWAT obeys all the rules of a civilian, including any penalties for killing them. You can't have more than one SWAT as a hostage at any time."

You can use this skill to take security guards hostage before first responders arrive and can force guards to surrender while unmasked. Guards and first responders do not count towards the one SWAT limit, you can take as many guards or first responders hostage as you want.

The Gunslinger skill line is based around making hipfire more reliable.

"As long as you have EDGE, your hipfire spread is decreased."
Spread is decreased by 30%. With some weapons this is unnecessary, but for weapons that have high spread you want to take this.

"As long as you have EDGE, hipfire shots will cause heavy stagger."

Another sleeper skill, Heavy Hipfire can synergise with Coup De Grace but has a (likely unintentional) hidden feature. The heavy stagger applied by this skill also applies on melee, meaning that as long as you have Edge and melee an enemy they will be heavy staggered. This works on specials (allowing you to melee shields from the front and stagger them) and can be used to stunlock guards in stealth at the cost of being unable to do anything else.

"If you have EDGE, the last shot of your magazine will consume it to deal 200% more damage."

This adds 2.0 to your damage multiplier, increasing it from 1.1x to 3.1x with no other damage skills. With a few weapons this damage increase allows you to kill SWAT in a single headshot, but it does allow a few weapons to kill SWAT in a single body shot (Bison, Castigo[?]).

The main benefit of Finisher is that it allows you to make builds with compact mags or low capacity weapons that are still effective against dozers, as the damage increase benefits all weapons against dozer visors. When used with the Red Fox you can also kill dozers in a single body shot, which can helpful in a pinch if you only have one bullet left.

"Increase your weapon swap speed."

This skill adds 30 to your weapon swap speed stat which amounts to increasing switch speed by 0.15s (assuming no weapon mods are attached).

The Hacker skill line is based around accessing cameras and remote stealth interactions.

"You can overload a device that already has an active Runtime. This will cause an electrical explosion that will stun anyone within range and destroy the device.
You gain one additional Runtime."

While this may not seem like a very useful skill, the overload ability is actually incredibly strong. It functions as an electrical stun affecting all NPCs within a 15m radius that have line of sight. The overload can be performed on cameras and drones, which will permanently destroy them. You cannot overload titan cameras. You need either Secure Loop or Routed Ping currently active to overload a camera.

When used in stealth affected civilians will become alerted and run away, triggering the alarm if they escape. Guards will become alerted and call a search.

"You can use one Runtime to make the security camera you're controlling loop its footage. Cameras looping their footage cannot detect you or anything out of the ordinary.
If the camera is destroyed, you regain your Runtime use. If you apply a new Runtime when you're at max Runtimes, your oldest active one is removed."

Looped cameras turn blue and are represented with a blue circle.

"You can spend a Runtime to make the hacked camera automatically mark any guards or law enforcement within its range.
Targets stay marked for 5 seconds after leaving the camera's view and do not count towards your maximum number of marked targets"

In stealth you can combine this with Secure Loop to create a safe area that marks guards, however you can use this skill in loud! On heists that don't have Cerberus Core you can set up Routed Ping on cameras overlooking key areas to mark all enemies that move through the camera's line of sight, allowing you to use skills that require enemies to be marked on normal SWAT. This is especially effective if titan cams are active.

Note that this skill is currently somewhat bugged, and applying Routed Ping to a camera after the alarm goes off will not work.

Cameras that have Routed Ping active are represented with a red circle.

The Tactician skill line is based around stuns, though it includes some smoke grenade bonuses as well.

"Whenever you stun or stagger an enemy, gain EDGE."

The infrasonic mine cannot trigger this skill.

On the surface this seems quite simple, but it has a lot of nuance. Shooting enemies can cause them to stagger which will give you Edge, however the game calculates damage after applying Edge.

This means that any weapon which requires Edge to kill in a single headshot can shoot an enemy and, if they stagger, proc Edge - despite the shot being fired without Edge the game will recognise that you now have Edge and include the 10% damage bonus in the damage calculation, turning what wouldn't have been a one shot kill into a one shot kill.

When this happens the hit marker is yellow instead of red, indicating a headshot but no kill. Despite this the enemy will die anyway.

Skills that require Edge (Cutting Shot, Precision Shot, Finisher) will not activate when you gain Edge in this way [VERIFY THIS? Cutting Shot definitely doesn't work]. If a skill consumes Edge you will gain the 10% bonus damage but the Edge icon will never appear due to being instantly consumed.

"Your flashbang, smoke grenade, and shock grenade area of effect is increased by 20%."

On flashbangs this extends their range from an 8m radius to a 9.6m radius - while this is a good improvement the normal range is already very large and covers almost all use cases. If you're making a build based around flashbangs and have an extra point, it wouldn't hurt to put it here (though it likely won't do much).

The effectiveness of Tactician Aced on smoke grenades is hard to quantify due to the inconsistent gradual propagation of smoke grenades. It does increase the final diameter of the smoke from 10m to 12m, however that only results in a 1m increase to the radius which is nearly unnoticeable even if you're looking for it.

The base radius on shock grenades is fairly small, but combining Tactician Aced with Demolitionist Basic increases the radius by 40% (from 3m to 4.2m). This presumably increases the distance it can chain as well, but this has not been tested.

"If you have EDGE, you will deal 10% more damage when you shoot a staggered or stunned enemy."

Infrasonic mines do not count towards this skill.

"Shots fired at enemies affected by your flashbang will ignore armor for as long as they are stunned."

The armor value of all affected enemies is set to 0 - once the stun expires their armor is restored. Because enemy armor is completely nullified this skill actually benefits the rest of your team, allowing all players to ignore armor even if they don't have the skill.

This skill also applies to enemies stunned by shock grenades.

"Any stun effects you apply last 20% longer."

This does not apply to the infrasonic mine or stagger.

The CQC Specialist skill line is based around improving human shields and takedowns.

"If you have RUSH and shove away a SWAT you held as a human shield, RUSH is consumed, and you repair your current armor chunk if it's damaged. This ability only triggers once per enemy.
You move 5% faster while holding a human shield."

Soft Assets effectively functions like using an ARK when you shove a SWAT, fully recovering the active chunk as long as it isn't broken. The Rush requirement is non-existent since CQC Specialist Basic gives you Rush whenever you grab a human shield, making this a free way of recovering armor when combined with throwable skills for infinite flashbangs.

Clean Slate does not work with Soft Assets.

"You perform takedowns 60% faster."

Takedowns normally take 5 seconds - with Groundskeeper they only take 2 seconds.

"If you have GRIT and shove away a SWAT you held as a human shield, GRIT is consumed, and the SWAT’s smoke grenade is triggered when they land. Only one grenade per SWAT can be triggered.
You move 5% faster while holding a human shield."

The smoke grenade that is spawned upon shoving a SWAT is treated as your own - it counts as throwing a smoke grenade and receives bonuses from any smoke grenade skills you may have.

The Scrambler skill line is based around ECM's, cameras, disrupting drones, and countering the techie.
"You can hack drones by spending one runtime. Stealth drones stop moving and are unable to detect you or your crewmates for 7 seconds, after which the stealth drone will continue working as normal and your runtime will be refunded to you. Combat drones will become indestructible for 6 seconds and fight on your side, after which they will self-destruct and your runtime will be refunded to you."
Scrambler basic is a strong skill on its own even if you don't intend to spec into the rest of the line, allowing the player to hack drones in stealth and loud while also blessing the player with an additional runtime allowing for synergy with hacker to loop 3 cameras at the same time.
"Whenever you place a tool, gain RUSH."
Scrambler aced awards
"As long as you have RUSH and an ECM Jammer is active, your hacking attempts, phone searches and QR code interactions are 50% faster and radios of guards you kill are answered instantly."

The Fortitude skill line is based around improving adrenaline and increasing survivability from sources of health.

"Increase your base maximum health by 50.
If you have no Adrenaline and you heal to or above maximum health, you gain or refresh GRIT."

This skill increases your max HP to 150, which after accounting for the 30 HP damage reduction is equivalent to 180 HP.

The Grit you gain from this skill does not count to Triage on the heal that applies it - if you have two buffs and then heal to gain Grit, you will only receive the healing you would expect from having two buffs. After gaining Grit from this skill you will get the full healing bonus on subsequent heals.

"The maximum number of 'downs' you can have is increased by 1, and your bleedout time is extended by 50%."

You start with one extra down, making Standard Lining go from 4 to 5 downs and Heavy Ballistic Lining/Adaptive Armor Lining go from 2 to 3 downs. Your bleedout timer is increased from 30 seconds to 45.

"When a crewmate heals using one of your Medic Bags, you heal for 40% of the amount they healed. Any amount of healing gained this way that exceeds your total health is gained as Adrenaline instead."

This skill is less effective than using medbags yourself, but is useful if you're building around giving heals to the team or you desperately need health and are away from any source of healing. With Supraphysiological and the base Steady Hands bonus you can gain up to 42% adrenaline from anywhere on the map any time someone uses your medbag without skills. If the person using your medbag has Triage then this can go as high as 69%, and with all teammates running Steady Hands this can go as high as 78% adrenaline. [re-read this recently, wtf are these numbers? Double check this]

The heal from Health Siphon resets Last Man Standing.

"Your maximum health is increased by 15 for each "down" you currently have."

With 5 downs from Fortitude Aced and Standard Lining you can get up to 225 HP (255 after accounting for the 30 HP damage reduction). When you go down the end of your health bar will turn red to represent the HP you are missing - you cannot heal above this point until you use a medbag to reset your downs.

The health you heal is a percentage of your current max health - if you have 5 downs and have been down twice, you will heal for a percentage of 195 instead of 225. If you use a medbag you will heal based on how many downs you have after using the medbag, not before - that is, if you have 0 downs and use a medbag you will heal for a percentage of 165 instead of 150 like you might expect.

As Unyielding increases your max HP, it also increases your max adrenaline - this means your adrenaline gain is effectively increased by 10% per down.

"Whenever you have Adrenaline, you gain 10% additional Adrenaline for each "down" you currently have."

The extra adrenaline is applied multiplicatively - with 5 downs this multiplier is 1.5, with 4 downs 1.4, and so on. Without skills FAKs heal 25% of your max HP but this is halved for adrenaline down to 12.5% - with 5 downs and Supra this only gets increased to 18.75%. If you have Steady Hands and 2 buffs for Triage then you will gain 56.25% adrenaline, enough to max out in two FAKs from full health.

The skill description may be a little confusing, but you gain the extra adrenaline even if you currently do not have adrenaline. The multiplier only applies to the adrenaline you gain; for example if you have 5 downs, 50% HP, and recover 100% health from a medbag (Steady Hands and Triage with two buffs), you will recover 50% of your max health to reach 100% health and then the remaining 50% healing will be multiplied by 1.5 for 75% adrenaline.

If you only have 1 point to spend on either Supra or Unyielding, Unyielding is always better as it has the same effect but also increases max health and, consequently, the adrenaline cap. You always gain the same amount of adrenaline from both skills, though Supra will be limited by the 150 adrenaline cap - the only time you should ever take Supra is if you already have Unyielding or if you have Assassin's Mettle.

"Your Adrenaline degrades 25% slower for each "down" you currently have.
If you have any amount of Adrenaline, you can use First Aid Kits to pause its degradation for 15 seconds."

This does not slow degradation to 0% - it increases the timer by 25% per down. With 5 downs this is a max of 125%, slowing adrenaline degradation from 2 seconds per point to 4.5 seconds per point.

"As long as you have Adrenaline and either EDGE, GRIT, RUSH, the effects of these buffs are doubled, and you take 10% less damage to your Adrenaline."

This may sound like a big buff but ultimately it's not particularly strong - the Edge bonus is interchangeable with any other 10% damage increase and will have varying effectiveness depending on your weapon. The Rush bonus is nice but not required, check the section on movement speed for more information.

You gain Grit when you gain adrenaline if you don't already have it because of Fortitude Basic, so you are guaranteed to take 30% less damage for 20 seconds upon gaining adrenaline. This is an effective increase of 28.5% adrenaline over normal Grit (43% without Grit), which can make it last considerably longer when combined with the other health increasing skills in the same line.

You gain 10% damage reduction if you have any buff, so having Edge or Rush will function like having normal Grit.

If you are planning on playing around adrenaline then this skill will greatly extend how long it lasts, otherwise you can ignore it.

"If you have a deployable bag in your loadout, it has 2 additional charges."

Increases deployable charges by 2 to a max of 8 in a single bag or 6 per bag with Deep Pockets (total of 12).

The Assassin skill line is based around marking enemies and silent kills.

"Whenever you kill an enemy with a suppressed weapon, gain RUSH."

As long as you have a suppressed weapon this allows you to have effectively infinite Rush.

"Whenever you manually mark a guard or law enforcement, refresh RUSH."

This does not work if the enemy is already marked - you need to wait for the mark to disappear before it will allow you to refresh Rush, which weirdly enough means this skill is less effective when you have Strategist Basic/Aced.

"As long as you are wielding a suppressed weapon, your crouching movement speed is increased by 20%.
This can't let you move faster than your current armor speed penalty allows."

Due to an oversight this skill isn't as useful as it necessarily sounds. Refer to the Movement Speed section for more information, but to summarise you only need +10% speed to hit max crouching speed - this skill is basically just a replacement for Rush and nothing else.

The only time the +20% bonus does something is if you crouch and ADS, because ADS lowers your movement speed more than normal.

"If you have no armor, killing a marked enemy with a suppressed weapon will heal you for 10 health. If you are at maximum health, this health will give you adrenaline instead."

This is the first source of healing added that gives a fixed amount of health instead of a percentage of your max HP - as such, it receives no benefit from skills that increase healing. The adrenaline gain from this skill is affected by Supra, allowing you to gain up to 15 adrenaline per kill instead of 10. This creates a unique situation where it's optimal to run Supra without Unyielding as the increased health means that you need more kills before you start gaining adrenaline, making it harder to benefit from Pain Asymbolia or Supra's enhanced adrenaline gain.