KF2 Perk Skills Reference: Every Skill Tested (Japanese Guide)

This is a translated, condensed version of a long Japanese guide whose author combined the in-game text, the Japanese wiki and the English wiki, found they disagreed or were unclear, and then switched each skill on and off in a test mode to measure it. Several skill names are translated back from the Japanese and may differ from the official English names, so confirm them against your in-game screen. Numbers below are the author's measurements.

How perk skills work

• A skill pair unlocks at every perk level that is a multiple of 5. Choose the left or the right; only that side takes effect.
• You can re-choose whenever you are allowed to: before deployment and during trader time. Pause (Esc), open the Perk screen and click Config. If you pick a different perk during trader time, the perk changes immediately and cannot change again until the next trader time. Check other perks' skills from the home screen instead.
• Mid-wave changes are queued and apply when the wave ends.
• Level 25 skills are ZED Time skills. They only work at ZED Time start or during it.
• Weapon-related skills usually only work on that perk's own weapons, with a few exceptions.

Switching tricks

• Start with a magazine-size skill and your starting weapon ammo grows by the added amount. If you fill the magazine, then switch to the opposite skill, the loaded rounds stay.
• A reserve-ammo skill does not raise your starting reserve ammo, except Demolitionist's Extra Ammo. If you buy ammo and then switch away, the excess disappears.
• Armor and HP boosts work similarly: start with the boost and you begin with the extra amount; switching away removes the excess above 100.
• Starting at 100 HP and then switching to an HP-boost skill increases max HP without raising current HP, so you can create a damaged state on purpose. The author explains a trader-time dosh loop in which a teammate heals you, you switch skills, and repeat. The money per trader time is small, best with a Medic healing, and the best target is a Berserker whose level 5 skill changes max HP by 100. Many players do not realize healing teammates gives dosh, so give up quickly if nobody understands.

ZED Time rules

• ZED Time triggers on kills or when a teammate falls. All motion becomes 20% speed for 3 seconds.
• Killing an enemy during ZED Time resets it to 3 seconds, once per ZED Time. Only Commando's perk bonus lets you refresh multiple times. It does not add time, so refresh near the end, before speed fully returns.
• After ZED Time ends, no new ZED Time can trigger for 10 seconds from the last start or refresh.
• If it has not triggered for a while, the trigger chance doubles, and after longer again quadruples; it resets on trigger.
• DoT kills (fire, poison), a single enemy killed by C4, kills by shrink effects from the Survivalist DLC weapon and kills by Commando DLC drones do not trigger or extend it. The patch notes mention that drones stopped counting, but this applies to the Sentinel only; kills by the HRG Bombardier count, though they rarely meet the conditions. A drone's self-destruct after running out of ammo or when repositioned is not treated as drone damage, so it can trigger ZED Time.

Berserker

Level	Option A	Option B
5	Dreadnought: max HP 200 (default 100). Stable tank, helps without armor, good with an active Medic.	Skirmisher: with perk weapon, move speed +20%, sprint +25%, regenerates 1 HP per second. Better solo, with no Medic, or on bosses.
10	Vampire: melee speed +20%, heal 3 HP per kill with perk weapons. Melee speed does not affect shooting, healing on kill does.	Butcher: damage and melee speed +20%. The same speed as Vampire, so the difference is heal-on-kill vs +20% damage. Works with ranged weapons too.
15	Resistance: damage taken -15%, poison and sonic further -15%. Unconditional. The Berserker's passive resistance is only up to 10%, so this brings it level with the Survivalist's 25%.	Parry: after a parry, 8 seconds of +35% attack, +5% melee speed and -30% damage taken. Needs parry skill; very good vs large Zeds.
20	Smash: heavy attack damage +50%, headshot damage +25%, flinch power +200% (headshot and flinch also apply to guns). Best with Zweihander and Battle Axe.	Massacre: light attack damage +30%, melee speed +5%. Good with Katana, Ion Thruster, and Frost Fang bash (counted as light).
25	Berserker's Rage: restore 50% of HP at ZED Time, and freeze Zeds within 10 m for 5 seconds. Heals 50% not 50 points, so with Dreadnought it is +100.	Spartan: you do not slow down in ZED Time; move, attack and even reload at normal speed. Simple and strong.

Commando

Level	Option A	Option B
5	Tactical Reload: ~20% faster reload on all perk weapons.	High Capacity Magazine: magazine +50%. Better vs large Zeds and for ZED Time extension. Does not affect single-shot grenade launchers or drone ammo.
10	Backup: 9mm/93R pistol and knife damage +85%, weapon swap time -50%.	Impact Rounds: flinch power +150%. Best with Mkb.42(H) and HMTech-401. Solo-oriented, since it may disturb teammates' headshots.
15	Tenacious: max HP and armor +25, start with 25 armor. Any armor lowers HP damage and 75+ takes 75% of hits.	Prepared: max ammo +20%. For FN FAL, M16 and HMTech-501.
20	Hollow Point Rounds: perk weapon damage +30%.	Eat Lead: magazine capacity +100%, stacking with High Capacity to +150%.
25	Tactician: faster reload and 2x weapon swap in ZED Time, which helps refreshes.	Machine Gunner: damage +3% and fire rate x3 in ZED Time (60% of normal because of slow motion). Good with large LMG magazines.

Support

Level	Option A	Option B
5	High Capacity Magazine: magazine +75%. Good for HZ12 and AA-12; no effect on Boomstick/Doomstick or HRG Buckshot.	Tactical Reload: faster reload on all perk weapons and pistols. Best for pump shotguns. The safe default.
10	Fortitude: max HP +50, damage taken -10%.	Salvo: perk weapon damage +30%. Simple and strong.
15	Armor Piercing Shot: damage +10%, penetration +4. Great in corridors.	Tight Choke: spread -50%, better at range and headshots.
20	Resupply Pack: your reserve +20%, and teammates taking ammo from you get +30%.	Concussion Rounds: flinch power +150%.
25	Penetrator: in ZED Time penetration +30, no damage falloff, faster reload.	Barrage: in ZED Time fire rate stays almost normal.

Field Medic

Buffs are applied to a teammate when you hit them with a heal. The author notes that the buff skills (Adrenaline, Focus, Coagulant) are multiplayer skills.

Level	Option A	Option B
5	Symbiotic Health: max HP +25 and heal 3% of max HP when you heal a teammate.	Low-HP resilience: every point of HP lost reduces damage taken by 1%, up to 30%.
10	Adrenaline Shot: healed target move speed +10%, up to +30%.	Combat Medic: magazine +50%, move speed +10%.
15	Focus Injection: healed teammate attack +5%, up to +20%.	Acidic Rounds: darts cost 20% less energy; hitting an enemy deals +100% and adds poison.
20	Coagulant Booster: healed teammate takes -10% damage, up to -30%.	Combat Surgeon: perk weapon damage +20%. Solo-oriented.
25	Airborne Agents: at ZED Time, spawns healing gas around you that also hurts enemies.	Sedative: perk weapon damage +30% in ZED Time, and killing an enemy releases a healing explosion.

Demolitionist

Level	Option A	Option B
5	Bombardier: perk weapon damage +25%.	Shock Trooper: faster reload and knockdown +10%.
10	High Impact Rounds: direct "shell" damage +25% (not explosion).	Extra Ammo: reserve ammo +10 (not C4, HRG Bombardier or the M16 rifle).
15	Sonic Resistant Rounds: Siren screams no longer disable your explosives.	Burst Rounds: blast radius +50% for all weapons, including dynamite.
20	Armor Piercing Rounds: direct damage +50% on weak spots.	Concussive Force: reaction, stun, flinch and knockdown +50%.
25	Annihilator: in ZED Time explosions become nuclear, no self-damage, no safety fuse.	Mad Bomber: in ZED Time fire and reload nearly normal speed, radius +25%, no self-damage.

Firebug

Level	Option A	Option B
5	Burn Them: perk weapon damage +35% (direct and ground fire).	High Capacity Fuel Tank: magazine x2.
10	Barbecue: burn duration +150%.	Ground Fire Wave: Ground Fire and residual flame damage +200%, plus a slow effect.
15	Napalm: burn duration +150%, and burning enemies ignite others on contact.	Zed Shrapnel: 30% chance a kill explodes, damaging and stunning nearby enemies.
20	Heat Wave: hitting enemies within 3 m always flinches them.	Firestorm: Chokeburn, Flamethrower and Microwave range +50%, ground fire +20% duration.
25	Pyromaniac: in ZED Time ammo does not decrease and fire rate is near normal.	Inferno: in ZED Time burning enemies spread flames, damage +50%, burned enemies -30% speed.

Gunslinger

Level	Option A	Option B
5	Steady: while aiming, damage +7.5% and no aiming move-speed penalty.	Quick Draw: less recoil from hip-fire, 2x weapon swap, move speed +5%.
10	Rack 'Em Up: a headshot counter. Each headshot adds a count, each count adds 10% damage, max 5; drops by 1 after 2 seconds without a headshot.	Hard Work: damage +20%, and +30% more on arm or leg hits.
15	Line Up: penetration +10, no damage loss when a bullet passes through.	Speed Reloader: faster reload.
20	Skull Cracker: headshotted enemies move 30% slower.	Beat Down: knockdown +410% when you shoot a running Zed's legs, flinch +410% on torso or arms.
25	Lead Storm: ammo in the magazine does not decrease in ZED Time.	Fan Fire: fire rate x3 and normal-speed reload in ZED Time; disables the ZED Time reload perk bonus.

Sharpshooter

Level	Option A	Option B
5	Sniper: when not moving, damage +25%.	Marksman: move speed +10%, fire rate +25%.
10	Stability: while crouching, damage +30% and reload +20%, plus +50% crouch move speed.	Ballistic Shock: stun power +100%.
15	Rack 'Em Up: the headshot counter skill.	Tactical Reload: faster reload.
20	Marksman's Skill: when aiming, headshot damage +10%, recoil -10%.	Always Prepared: reserve ammo +25%, grenade capacity +1.
25	Assassin: headshot has a 5% chance to trigger ZED Time; in it headshot damage +35%.	Ranger: same 5% chance; in ZED Time a headshot always stuns.

SWAT

Level	Option A	Option B
5	Heavy Armor Training: Clots cannot grab you (even at 0 armor), and you start with 50% armor.	Tactical Movement: move speed +20%, no slowdown while aiming or crouching.
10	Close Quarters Training: pistol, knife and bash damage +100%, and you start with two pistols.	Tactical Reload: faster reload.
15	Suppression Rounds: flinch power +200%.	Ammo Vest: reserve ammo +30%.
20	Assault Armor: max armor +50 and start with 75.	Weakening: perk weapon slow effect +15.
25	Ram: in ZED Time you are not slowed, move +25%, and knock down enemies you hit.	Rapid Attack: in ZED Time fire rate near normal, no ammo use, flinch +100%.

Survivalist

Level	Option A	Option B
5	Tactical Reload: faster reload for Commando, Gunslinger and SWAT weapons.	Heavy Weapons Training: faster reload for Support, Demolitionist, Sharpshooter weapons and the Freezethrower.
10	Medic Training: all healing +30%, syringe and dart cooldown halved.	Melee Expert: melee damage +75%, speed +20%, move speed +25% with a melee weapon.
15	Ammo Vest: reserve ammo +15%, Medic Grenade unlocked.	Weapon Harness: max weight +5, Molotov unlocked.
20	Zed Shrapnel: 30% chance a kill explodes and stuns nearby enemies.	Make Some Boom: all explosions +50% radius, explosion damage taken -50%.
25	Madman: fire rate x3 in ZED Time.	Lockdown: in ZED Time every weapon stuns every Zed (except the Killerwatt beam).

For a Survivalist example see Pulverizer build. For weapon sets by perk see Japanese loadout builds.