SAS Zombie Assault Wiki
Skill Point.png

In SAS: Zombie Assault 4, the player earns a skill point to spend on skills every level when leveling up. Upon creating a new character, that character will automatically have one skill point into its first class skill. Originally only a maximum of 100 skill points could be obtained. However, in the Flash Version an additional 8 can be earned with the addition of the Augmentation Rewards Update, added on the February 3rd, 2015.

Players can only spend up to 25 skill points in a single skill. For Steam version, it costs US$3 per respec.

General Skills

These are skills available to all classes.

Skill Logo Skill Description Initial Max Growth Related Achievements
Fast Reload.png
Fast Reload-Mobile.png

Fast Reload

Decrease reload time

3.5% 58.96% reload speed increased by 100*(1-0.965^levels)%

See notes for stacking

Growth chart
Reload time skill growth chart sasza4.png
Fast Movement.png
Fast Movement-Mobile.png

Fast Movement

Increase movement speed

+3% +39% +1.5% move speed / level Quicksilver


Increase max HP

+300 Max HP +7500 Max HP

+300 Max HP / level

Augment stacks multiplicative

Recovery Time.png
Recovery Time-Mobile.png

Recovery Time

Reduce your recovery time when knocked down in multiplayer games

10% 130%

5% / level

See notes for stacking

Health Regen.png
Health Regen-Mobile.png

Health Regen

Passively regenerates your health over time

+2.5 HP/sec +62.5 HP/sec +2.5 HP/sec regen per level Regenerator
Pay Grade.png
Pay Grade-Mobile.png

Pay Grade

Increase the end of mission cash reward. Affects failed mission cash reward as well.

+12.5 % 312.5% +12.5% cash reward / level none
Body Armour Expert.png
Body Armour Expert-Mobile.png

Body Armour Expert

Increase the total resistance for all armour worn

7% +175%

+7% / level

Energy Boost.png
Energy Boost-Mobile.png

Energy Boost

Increase max energy

+10 max energy point +250 max energy point +10 max energy point / level none
Energy Regen.png
Energy Regen-Mobile.png

Energy Regen

Increase the amount of energy regenerated per seconds

+0.25 +6.25 +0.25 point / sec regen per level Regenerator
Field Supplies.png
Field Supplies-Mobile.png

Field Supplies

Get extra premium ammo for current active gun used whenever you pick up any loot (Maxed at 100 per loot)

15% of clip size 375% of clip size

+15% clip size / level

Rounded up

Grenade Damage.png
Grenade Damage-Mobile.png

Grenade Damage

Grenade do extra damage

+15% damage +375% damage

+15% damage / level

Critical Shot.png
Critical Shot-Mobile.png

Critical Shot

Chance per shot to do more damage (base crit damage is +100% without any level)

Chance +4% , Damage +105% on crit rather than +100% Chance +16%, Damage +201% on crit rather than +100% +0.5% chance & +4% crit bonus damage / level

See notes for Critical Damage stacking



  • For reload speed, the number stacks multiplicative with base reload speed first, then other multiplier augments or other reload speed effects. For example a gun with 2 seconds with reload speed 50% from skill +  25% reload speed from nimble augment + 50% from Adrenaline will results in calculation of 2 x (1-0.5) x (1-0.25) x (1-0.5) = 0.375 sec reload time instead of instant reload. Titan IDS arm and nimble augment stacks additively as one multiplier.
  • For recovery speed, the calculation: base recovery time / (1 + (1 x recovery skill multiplier) + 0.25 if rubicon equipped + (1 x total percentage of resuscitating augment)) = current recovery time, if a nearby medic exists with speed up recovery aura, it will further reduce current recovery time / 1+(1 x medic skill multiplier)
  • For the Body Armour Expert skill, the multiplier is applied to both the armour's base resistances AND augmented bonus resistances.
  • The damage reduction formula:
    sqrt((total displayed resistance BASE number x (1 + Body Armour Expert skill multiplier)) + total of augment bonus + total of mastery bonus + medic aura if exist ) = actual damage reduction.
    For heavy class, the left over percentage is then reduced again by Toughbody if exists or Die Another Day skill if activated. For example 30% damage reduction from armor would result for level 25 Toughbody which have 56% damage reduction to be only effectively only (70% left over x 0.56 ) = 39.2% added value for end total of 69.2% damage reduction.
  • Critical Damage increases the damage multiplicatively from the displayed number of damage of the gun used only. For example with head augment which increase damage for 15% and critical hit 25 (+200% crit damage ) will make the gun does a total of 315% damage from 100% base + 15% + 200% crit instead 345% from (100% base + 15%) * 300% on critical hits. Please also know that Critical hits, like other additional damage buff, does not increases DoT damage caused by the gun nor damage from active skills.

Assault Class Skills

Skill Logo Skill Description Initial Max Growth Related Achievements


Increase movement, firing and reload speed for short duration (20 energy cost, 25 sec cooldown)

+25% move speed, rps and reload speed for 5 seconds +53.82% faster for 11.0 seconds

speed = 100*(1-0.75*0.98^(levels-1))%

(Average of 1.17% / level)

+0.25 sec duration / level

see notes

Deadly Force.png
Deadly Force-Mobile.png

Deadly Force

Increase global gun damage

+1% gun damage +25% gun damage

+1% gun damage / level

see notes for mobile version stacking

Close Quarters Combat.png
Close Quarters Combat-Mobile.png

Close Quarters Combat

Slash knife to enemies entering skill range (10 energy cost, 0 second cooldown)

+750 damage with 45' arc and 1m range +5550 damage with 93' arc and 2.2m range

+200 damage, +2 arc, + 0.05m range / level

see notes

Pistol Whipped
Gun Mod Expert.png
Gun Mod Expert-Mobile.png

Gun Mod Expert

Decrease gun augmentation cost, increase augmentation reward xp

5% reduced cost, +10% aug xp 48.26% reduced cost, +250% aug xp

+(4-0.16*(level-1)%, +10% aug xp / level

Stim Shot.png
Stim Shot-Mobile.png

Stim Shot

Heals when health is below 20% (120 seconds cooldown)

15% HP/sec for 2 seconds, 34 energy cost 21% HP/sec for 4.4 seconds, 10 energy cost

+0.25% HP/sec, +0.1 sec duration, -1 energy cost per level

Killing Spree.png
Killing Spree-Mobile.png

Killing Spree

Kill 20 zombies to activate increased damage and pierce. Keep killing to refresh duration

+30% damage and pierce for 2 seconds +150% damage and pierce, lasts 4.4 seconds

+5% effect, +0.1 sec duration

Assault Team.png
Assault Team-Mobile.png

Assault Team

Calls in an assault team to your position (60 energy cost, 120 seconds cooldown)

15 sec duration, 3 sas team, 10% damage, 1500 HP 63 sec duration, 4 sas team, 250% damage, 13500HP

+2 sec duration, +10% damage, +500 HP / level. +1 sas team on level 20

see notes

Field Commander


  • Adrenaline skill's RPS and reload speed stacks multiplicative, move speed stacks additionally.
  • Deadly Force stacks with Deadly augments and Elite Augment Cores. Prior to 1.10.2, this bonus only applied to base damage, making it as little as 30% as powerful as intended.
  • Close Quarters Combat has a slashing animation for 0.X seconds depending on the level, during which player can move (free backpedal speed) and any enemy caught in the area will still be damaged thus extending the attack area. During this animation however, some guns cannot be fired, meaning the player has to be careful when using it.
  • Only one assault team can be called at a time.
  • The assault team members use HVM Assault rifle, shotgun and MPG rocket launcher on random order. They only have pierce of 1 except for rocket launcher and the damage dealt is "n" percentage of the mentioned weapons, they also have same ammo capacity and requires reload. They also do not damaged by acid blood death pool or spitter and regurgitator (left over) acid pool.

Medic Class Skills

Skill Logo Skill Description Initial Max Growth Related Achievements


Drops a field medkit that heals any SAS who pick it up (45 energy cost, 4 sec cooldown)

heals 400 health heals 4000 health

+150 heal per level

Protective Aura.png
Protective Aura-Mobile.png

Protective Aura

Increases the thermal and chemical armor value for player and nearby allies (passive)

2m radius, +75 armor 4.4m radius, +1875 armor

+0.1m radius, +75 armor per level



Boosts revive time and health of nearby fallen teammate (passive, active when 1m or closer to fallen teammate) health boost is % of revived player's maximum health

+18% speed, +5% health +150% speed, +125% health

+5.5% speed, +5% health per level

Biocleanse Bomb.png
Biocleanse Bomb-Mobile.png

Biocleanse Bomb

Slows zombies by 50% and lowers their resistance by 50% when in blast radius (20 energy cost, 5 sec cooldown)

2m blast radius, 3 sec duration 4.4m blast radius, 15 sec duration

+0.1m blast radius, +0.5 sec duration per level

Cleanup on Aisle 13
Bad Blood.png
Bad Blood-Mobile.png

Bad Blood

Melee attackers take damage every time they strike you (passive)

40 damage to melee attacker 1000 damage to melee attacker

+40 damage per level

Final Farewell.png
Final Farewell-Mobile.png

Final Farewell

When you go down you heal everyone around you and drop medkits (active when player goes down, no cooldown*)

3.5m heal radius, 40% heal, 4 medkits 8.3m heal radius, 112% heal, 11 medkits

+0.2m heal radius, +3% heal per level. +1 medkit every 3 levels

Zombie Antidote.png
Zombie Antidote-Mobile.png

Zombie Antidote

Huge gaseous explosion of virus antidote does large damage to zombies in the radius (80 energy cost, 60 sec cooldown)

2m blast radius, 6000 toxic damage over 8 seconds 4.4m blast radius, 150000 toxic damage over 32 seconds

+0.1m blast radius, +1 sec duration, +6000 total damage spread over duration per level

Zombie Heal Thyself


  • Medic's dropped Medkit lasts for 15 seconds before it disappears. Unlike the normal Medkit drop which is permanent. In mobile version, the dropped Medkit cannot be moved by a player but can be pushed by moving an object through it.
  • Biocleanse Bomb stacks by multiplying with gun adaptive augment.
  • Protective Aura is not affected by Body Armor Expert.
  • Final Farewell is stated to have 150 seconds cooldown. This is false information actually just to prevent the state-check activated repeatedly, avoiding the bug which allows a dead player to get Final Farewell activated multiple times in single recovery period.
  • The number of extra HP gained through Revive is relevant to how long the medic stays with the fallen.

Heavy Class Skills

Skill Logo Skill Description Initial Max Growth Related Achievements
Hold The Line.png
Hold The Line-Mobile.png

Hold The Line

While standing still, increases your damage and weapon penetration for a short time (30 energy cost, 30 sec cooldown)

8 sec duration, +30% damage and pierce 27.20 sec duration, +126% damage and pierce

+0.8 sec, +4% damage&pierce per level

Heavy Gear.png
Heavy Gear-Mobile.png

Heavy Gear

Reduces percentage of negative movement effects for weapons and armor (passive)

-10% movement penalty -100% movement penalty

-3.75% per level

Tough Body.png
Tough Body-Mobile.png

Tough Body

You are so tough you are more resistant to damage than normal (resists Dark Minion zombies' attacks) (passive)

6% damage reduction 54% damage reduction

+2% per level

Die Another Day.png
Die Another Day-Mobile.png

Die Another Day

Become 90% immune to damage for a short time (39 energy cost, 50 sec cooldown)

90% immunity for 4 sec 90% immunity for 10 sec

+0.25 sec per level

Not Today
Brute Strength.png
Brute Strength-Mobile.png

Brute Strength

Your brute strength allows you push through obstacles and damage enemies in your path (passive)

+50% push force, 30 damage to zombies +530% push force, 750 damage to zombies

+20% push force, +30 damage per level



Your shots have a chance to stun enemies (passive)

5% chance, 0.5 sec stun 17% chance, 1.7 sec stun +0.5% chance, +0.05 sec per level
Only applies on player's guns' projectiles, including bullets, rockets, lasers, blades, and flames. The chance depends of number of fletchettes, making multi-fletchette weapons ideal with this skill.
Aerial Bombardment-PC.png
Aerial Bombardment-Mobile.png

Aerial Bombardment

Powerful orbital strike deals huge damage in a targeted area (60 energy cost, 90 sec cooldown)

6 blasts, 2000 damage each, 4m blast radius per blast 14 blasts, 32000 damage each, 4m blast radius per blast

+1 blast every 3 levels; +250 damage per level

Zombies Go Boom


  • Hold the Line effect stays active when the player pushed by forced movement such as zombies or other players.
  • Heavy Gear is counted before Masteries and Collection Rewards when calculating movement penalties.
  • Tough Body vs. Toughness, which will help you live longer?

    Toughness is better before level 48, after level 48 Base Health is high enough that maxing Tough Body becomes more important.