Pin the cores, burn the brood, break the beast—every KF3 boss solved.

Hub — Your Three-Boss Playbook

Killing Floor 3’s launch roster features three boss fights: Queen Crawler, Impaler, and Chimera. Each one caps a five‑wave run with a dedicated boss wave, and each comes with unique damage-type weaknesses, breakable weak points, and execution finishers that punish sloppy revives.

Below is the “at‑a‑glance” overview. Click through (or scroll) to each boss page for complete counters, loadout notes, and team tactics.

At a Glance

• Queen Crawler — Heat and Biological damage work best. Prioritize the glowing mouth and rear abdomen pustules; later phases add Mire portals and more hatchlings. Destroys downed players.
• Impaler — Weak to Electrical and Acid damage. Break forearm cores early, then pop back tubes/cores; interrupt missiles while charging. Multiple Impalers can spawn with larger groups; kiting and isolation are key. Executes downed players.
• Chimera — Weak to Force and Cold; heavy armor up front, then exposes more weak points at half HP. Shoots Mire energy orbs (destroy them), gains a ranged orb volley and short‑range teleports in phase 2. Also executes.

Universal prep

• Bring at least one Fire/Heat option, one Electric option, and one Force/Armor‑breaking option across the squad so you can pivot mid‑fight.
• Keep someone on egg/orb duty (Queen/Chimera) to prevent adds from snowballing.
• Assume bosses execute downs—don’t crawl to “help.” Stabilize from cover and clear space first.

Queen Crawler — Full Guide

Weak to: Heat, Biological. Resists: Force, Acid. Weak points: Head, inner mouth, rear abdomen pustules, abdomen scar pustule. Mechanics: Eggs, web traps, late‑fight Mire portals; executes downed players.

TL;DR Win Condition

1. Kill eggs/webs on sight to control the arena.
2. Burn the Queen—Heat damage melts her quickly; then ADS the mouth or rear pustules during Zed Time.
3. In phase 2, avoid Mire portals (she can emerge with burst damage). Keep distance and keep burning.

Loadout & Mods

• Heat: Incinerator M7 and any gun with Incendiary Rounds/Shells capitalize on her listed weakness. If your primary doesn’t support Heat, consider an underbarrel or sidearm that does.
• Biological: If your build includes weapons/mods that deal Biological damage, it’s a secondary boost here. Avoid Acid—she’s resistant to it.

Map & Positioning

• Hold a lane with cover and line of sight for the rear pustules; don’t chase into tight corners where eggs/webs accumulate.
• Mobility tools (slides, ziplines) help reset spacing when she lunges or leaps.

Phases & Counters

• Phase 1 (50–100%):
  • Spits eggs that hatch into Crawler Larvae plus web traps that slow you. Shoot both immediately; they’re destructible.
  • Weak-point fishing: Aim for inner mouth when she roars or rears; otherwise light up rear pustules between lunges. Zed Time is your friend.
• Phase 2 (≤50%):
  • Spawns Mire portals and can burst out for heavy contact damage. Watch the purple portals and sidestep pre‑emptively; re‑establish distance before returning fire.
  • Her hind weak points consolidate into a single glowing spot behind her; keep flanking to expose it.

Team Roles

• Firebug‑type: Lead DPS with Heat and area denial on adds.
• Sharpshooter‑type: ADS mouth and hind pustules during Zed Time.
• Medic‑type: Pre‑top teammates before portal punishes; do not revive in line of a portal.
• Engineer‑type: If a turret’s available on the map, park it on egg lanes for auto‑clear while the team focuses the Queen. (Turrets are specifically useful vs. adds.)

Common Mistakes

• Ignoring eggs/webs (you’ll get swarmed).
• Running in circles instead of holding ground with Heat DPS—she’s fast enough to punish running; controlled retreats are better. (Community feedback often rates her as the easiest of the trio—if you control eggs/portals, she drops fast.)

Impaler — Full Guide

Weak to: Electrical, Acid. Resists: Cold, Biological. Weak points: Head, forearm cores, back tube cores, rear core. Mechanics: Sprinting pounces with a red blade state, charge‑up missiles you can detonate on its back while charging, and multi‑spawn in larger parties; executes downed players.

TL;DR Win Condition

1. Break the forearm cores first to disable later rockets and farm Zed Time.
2. Shoot the missile bays while they’re charging (back glows) to cause self‑damage and interrupt.
3. Keep distance, kite on a loop, and isolate when multiples spawn.

Loadout & Mods

• Electrical: Ammo mods like Electric Slugs plus electric grenades are premium picks—shock helps control its movement and punishes blade lunges.
• Acid: Acidic Ammo deals bonus damage and chews through the cores quickly.
• Force/Armor‑breakers: Handy once cores are cracked to chunk health, but priority is still Electric/Acid.

Map & Positioning

• Track it constantly—it’s deceptively fast and loves to appear on top of you. Ping regularly in co‑op, and keep a kite loop that avoids hard dead‑ends. Use slides/ziplines to reset spacing.
• Isolation: When two or three spawn, split their aggro across lanes so only one has line of sight at a time. (Game data and community experience both support isolating multiples rather than dogpiling.)

Phases & Counters

• Opening (100–66%):
  • Forearm cores: Focus fire to stop future rockets; forearm shots also build Zed Time, giving your team slow‑mo windows to keep hitting cores/head.
  • Red blade: When the horn/blade glows red, it hits harder and won’t be interrupted by chip damage—don’t face‑tank; stutter‑step and side‑dodge the lunge, then punish the recovery.
• Mid (66–33%):
  • Missiles charging: The back glows before launches—shoot the bays to trigger a backfire and cancel the volley. Once missiles are in flight, you can’t shoot them down.
  • Keep working the back tube cores and rear core when Zed Time triggers or you’ve created space.
• Low (≤33%):
  • It accelerates and chains lunges. Shock keeps it manageable; Acid continues to tick. Coordinate staggered slows rather than blowing everything at once.

Team Roles

• Electric DPS (e.g., AR/DMR with Electric Slugs): Anchor that keeps the Impaler “honest.”
• Explosives/Force: After cores are down, burst big chunks on its body.
• Medic‑type: Keep stims for the post‑lunge punish; assume executes on downs.

Advanced Positioning (Community)

High ground that forces a mantle can give you breathing room—especially against a single Impaler—letting teammates rotate and reload. Don’t overuse; some arenas don’t have safe perch loops.

Common Mistakes

• Ignoring forearms first—you’ll eat rockets later.
• Trying to outrun it in straight lines—kite in loops, side‑dodge lunges, and use mobility tools.

Chimera — Full Guide

Weak to: Force, Cold. Resists: Heat, Electrical. Weak points: Head, glowing arm, chest, head pustules. Mechanics: Heavy armor at start; Mire energy orbs that spawn zeds (shoot them), ground tentacle projectiles, and in phase 2 a ranged orb volley plus short‑range teleports; executes downed players.

TL;DR Win Condition

1. ADS the chest/head through armor (or use Force to break it) until half HP.
2. Destroy Mire orbs immediately to prevent add spawns; avoid ground tentacles.
3. In phase 2, dodge/cover the orb volley, listen for teleport audio, slide away, and resume DPS on exposed zones.

Loadout & Mods

• Force / Cold: Weapons like Vulcan TA (Force) or Samaritan (Cold) counter the listed weaknesses. If your main kit doesn’t have these types, prep a secondary or mod path that does.
• Armor considerations: Early fight feels “brick‑walled” without armor‑breaking—Force helps shred plates; at ~50% it sheds armor and exposes additional weak zones (arms/back), making damage flow faster.

Map & Positioning

• Loop the map and memorize ziplines and any turrets—Chimera’s adds will overwhelm you if you try to face‑tank. Turrets can handle orb‑spawned zeds while your team focuses the boss.

Phases & Counters

• Phase 1 (100–50%):
  • Armor‑heavy: If you lack Force, ADS the chest/head to ensure hits even through recoil.
  • Mire energy orbs: Shoot these ASAP to stop spawns. Ignore and you’ll be fighting the room, not the boss.
  • Ground tentacles: Sidestep or jump to avoid—don’t waste ammo trying to break them.
• Phase 2 (≤50%):
  • Armor shed: Arms/back cores become fair game—dump Force/Cold here.
  • Orb volley: New ranged attack with multiple spheres—shoot them down or break line of sight behind cover/angles.
  • Teleport: A sharp audio cue precedes a short‑range blink near the target—pre‑slide on cue to avoid the follow‑up slam.

Team Roles

• Force/Cold DPS: Core damage dealer; focus glowing arm, chest, and newly exposed cores in phase 2.
• Add Control: One player dedicated to Mire orb denial; they should prioritize angles over boss DPS.
• Engineer‑type: Turret placement on add lanes; keep a Multi‑Tool ready to set/repair.
• Medic‑type: Pre‑top before orb volleys/teleports; discourage risky revives because executes are common.

Common Mistakes

• Tunneling boss HP while ignoring Mire orbs—adds will spiral.
• Standing still for volleys—angle break or pop them midair.
• Under‑valuing Force—it’s the difference between “stuck on armor” and “snowballing phase 2.”

Extra Notes, Patches & RNG

• Spawn RNG varies by session; players report streaks of one boss or another. Don’t assume equal distribution across a play session.
• Community‑tested tricks like elevation/mantle abuse can help, but rely on map geometry; treat them as emergency tech, not a game plan.

Alternate Builds & Quick Picks (if you like checklists)

• Versus Queen Crawler: Heat primary (Incinerator M7 / Incendiary Rounds), ADS for mouth/hind; one teammate assigned to egg/web cleanup; avoid Mire portals in phase 2.
• Versus Impaler: Electric primary (Electric Slugs) + Acid secondary (Acidic Ammo); forearms → back tubes → rear core; shoot missile bays during charge; kite loops; isolate.
• Versus Chimera: Force/Cold primary (Vulcan TA / Samaritan); shoot Mire orbs, ADS chest/head, prep for phase‑2 volley + teleports; leverage turrets on add lanes.

Aftercare: Boss‑Specific FAQs

Q: Do all bosses execute downed players?
A: Yes—each of the three has execution behavior. Don’t attempt “hero” crawls; clear space and coordinate a safe revive.

Q: Is Queen Crawler “the easy one?”
A: Many players say so, if you handle eggs/webs and portals properly. Sloppy control can make her just as punishing.

Q: Best generic counter if I don’t know which boss is coming?
A: Carry one Heat option (Queen), one Electric option (Impaler), and something with Force/Cold (Chimera). That trio covers all listed weaknesses.