Warhammer 40k Chaos Knights – 9th edition army guide

Chaos Knights are a fearsome, mechanical force of terror in Warhammer 40k - here's our guide to their codex, dread households, tactics, and more

Warhammer 40k Chaos Knights guide - Author photo showing a Chaos Knight model head on, with glowing eyes

To understand Warhammer 40k’s Chaos Knights is to understand what can happen when great power, supreme technology, and overwhelming pride are left to fester for millennia. Before the rise of the Imperium of Man, when the first human galactic civilization fell into Long Night, each and every human world stood alone, easy prey for deadly xenos and more sinister things lurking in the dark between stars.

Yet throughout this time of suffering, the Imperial Knight Houses stood proud. Piloting mighty walking war engines, bearing terrible armaments from the time of man’s greatness, they were blazing torches in the dark. When the Emperor’s Great Crusade reunited mankind’s lost domains, the Knight worlds pledged their blades to his cause. But a flame can gutter. Might begets hubris and pride ushers in a fall. When the arch-traitor Horus Lupercal turned his guns on the Imperium he brought with him many Knightly Households: the spurned, the avaricious, the bloodthirsty, and the cruel. In the age of Warhammer 40k, these ignoble cavaliers are known as the Chaos Knights.

When the Horus Heresy failed, the surviving renegade knights fled into the Eye of Terror, claiming hellish new domains in warp space. Some fallen Knights still observe perverse mockeries of their chivalric oaths, while others barter with daemons and the twisted genius of the Dark Mechanicum. When they ride forth to war, worlds burn in their wake.

This is our guide to Warhammer 40k’s Chaos Knights, an elite force of devastating, monstrous war engines that blend ancient technology with daemonic cruelty.

Here’s what to know about Chaos Knights in Warhammer 40k:

Warhammer 40k Chaos Knights guide - Games Workshop photo showing the Chaos Knights 9th edition codex cover artwork

Chaos Knights codex

Though corrupted by the warp, the Questor Traitoris pilot similar Knight suits and bear the same formidable arms as their loyalist counterparts, just with more spikes and black metal names. Our guide to Imperial Knights explains the core of that armoury, as well as how to construct detachments or field Knights as allies.

Knight Tyrants are analogous to the mighty Knight Castellan and Knight Valiant, fielding the same immense armament. Similarly, War Dogs are a Chaotic corruption of the loyalist Armiger-class Knight, with the Executioner and Huntsman built to the same standards as the Armiger and Warglaive (but with spikes on).

Slaves to darkness: Our guide to Warhammer 40k Chaos factions

The Stalker, Karnivore, and Brigand stray further from the holy STC of the Armiger, cursed machines haunted by Pterrorshade warp entities. The Karnivore is given over entirely to melee slaughter and the Brigand to close-range firepower, while the Stalker freely mixes armament.

War Dogs lope alongside their masters like the curs they are, benefitting from aura abilities projected by their masters: while close to a Knight Rampager, War Dogs will reroll natural to-hit rolls of one as their bellicose lord drives them into frenzy.

Warhammer 40k Chaos Knights guide - Author photo showing a Chaos Knight War Dog model

The Abhorrent-class knights are the mainstay of any traitor house. Freed from the tedium of Imperial dogma, the Knight Despoiler can mix and match its ranged weapons, letting dakka fanatics mount twin Despoiler Gatling Cannons and a Ruinspear missile pod on a single Knight. The frenzied Knight Rampager is armed with a Reaper Chainsword and Warpstrike Claw in mockery of the loyal Gallant.

The Knight Desecrator wields the unique Laser Destructor, a long-range laser that can melt through any armour and total tanks with its vicious d3+6 damage. Consider upgrading to the relic The Diamonas, which – at S16 instead of S14, and Heavy 3 instead of Heavy 2 – is half as much gun again.

Warhammer 40k Chaos Knights guide - Warhammer Community photo showing a Chaos Knight Abominant model

Knight Abominant

Perhaps most corrupt of all is the Knight Abominant. This beastly behemoth wields a Volkite combustor, a weapon of ancient provenance that can cause explosive bursts of mortal wounds, an infantry-threshing Electroscourge and tail-mounted Balemace.

This Knight’s greatest corruption is spiritual. The Knight Abominant is a psychic monstrosity that can call forth psychic powers from the Warp Storm Discipline.

Book days: Read our Warhammer 40k codex release date guide

While feeble Imperial Knights are restricted to corporeal weapons, the Abominant can blast enemies apart in the Psychic Phase with Coruscating Hate or render an enemy unit powerless against the traitors’ melee prowess with the Storm Malevolent.

Scornful of sorcery? Magic-hating worshippers of the Blood God Khorne can still pilot a Knight Abominant. The Knight will lose its (cowardly, treacherous) psychic powers, but gain +1 WS and +1 Attack to better channel its unholy rage.

Warhammer 40k Chaos Knights guide - Author photo showing the Chaos Knight Rampager

Chaos Knights Dread Households

Chaos Knights are drawn from traitorous Dread Households, each with a unique war culture and army-wide rules, relics, and stratagems. The Households are either frenzied Iconoclasts or demon-pledged Infernal Households.

The Chaos Knights Dread Households in the latest codex are:

  • House Herpetrax
  • House Khymere
  • House Lucaris
  • House Khomentis
  • House Korvax
  • House Vextrix

While all Knights must engage in melee to contest objectives and bring their foes to ruin, Iconoclasts take this to extremes, granting each Knight +1 attack and -1AP in the first exchange of any melee. Iconoclasts can be drawn from the Dread Households Khymere and Lucaris – both with further melee prowess – or doughty House Herpetrax, whose War Dogs have two extra wounds and other Knights four extra wounds.

Put it together: Read our Warhammer 40k detachments guide

Infernal Knights trade their own vitality for Daemonic Surges, fickle boons of the warp, able to suffer one mortal wound in exchange for a random buff that could make them ignore wound rolls of 1-3, increase speed or the damage of a weapon for a turn, or d3 to pick the boon. Resisting wounds is formidable, but it only matters against S9 and above weapons, so it should be clear based on your foe’s weapons when this is the right choice.

The Knights of the demonically infested Dread Household House Khomentis have more control over their Daemonic Surges, the elite House Vextrix can re-roll one hit and wound roll every time they shoot. House Korvax, who have rules for the first time in 9th edition, ride a wave of terror, making greater use of the Chaos Knights’ Harbingers of Dread ability.

Warhammer 40k Chaos Knights guide - Author photo showing a Chaos Knight Despoiler

Chaos Knights and the Marks of Chaos

A fantastic addition to Chaos Knights for 9th edition is the ability to pledge each of your Knights to a particular chaos god. For 1CP a Knight can kneel at the throne of one of the Chaos powers or even the Undivided Pantheon, gaining their ‘mark’, as well as access to a powerful new stratagem. Adherents of Nurgle have an Abominable Constitution, fighting as though they had suffered no damage, while the lackeys of Khorne can wrack the minds of enemy Psykers with the perils of the warp.

For an investment of points or Power Level, your Knights can claim the Favour of the Dark Gods. Each Favour pledges your Knight to one of the great powers and grants it an ability befitting its new master.

40k XCOM: Our Warhammer 40k Chaos Gate Daemonhunters review

Tzeentch’s Pyrothrone can turn any knight into a pskyer or increase the psychic might of a Knight Abominant, while the Beguiling Majesty of Slaanesh reduces melee to-hit and to-wound rolls against the Knight by one.

Should the Knight make a worthy offering to their patron (by slaying sufficient wounds of enemy models) they will be rewarded with even greater favour. The pantheon undivided can offer the Blessing of the Dark Master, preventing enemies re-roll hit, wound or damage rolls when targeting the Knight. Should the Knight become favoured, the blessing will also cause all unmodified hit rolls of 1-3 to miss them.

Warhammer 40k Chaos Knights guide - Author photo showing the Chaos Knight Tyrant model

Harbingers of Dread

Where the Chaos Knights walk, reality quakes. They are accompanied by a rising tide of dread, shattering the minds of their foes and, eventually, the very stuff of reality itself – represented in-game by the Harbingers of Dread rules.

Chaos Knights project a pall of Dread, usually 12” around their bases. This acts like an aura ability but isn’t shut down by things that would normally turn off auras: no amount of trickery can make a Chaos Knight any less terrifying.

Learn the ropes: Our guide on how to play Warhammer 40k

Some Knight abilities may force an enemy to take a Dread Test, rolling 2d6 and hoping to roll equal to or under their Leadership or suffer the consequences.

Over the course of the battle the nature of this Dread will warp and shift as you choose either a Doom, Despair or Darkness Harbinger ability. Think of these as three sinister channels, with Doom in the middle and Despair and Darkness to either side.

Warhammer 40k Chaos Knights guide - Author photo showing a Chaos Knight model faceplate

At the start of the battle the Knights are Harbingers of Doom, and those caught within their Dread range suffer -1 Leadership and -1 from Combat Attrition tests.

In subsequent rounds, the effects of Dread will build, with the Knight player choosing either to stay in their current channel and stack the next level of its ability – or move to one of the adjacent channels, to claim its boon instead.

Heretic Astartes: Our Warhammer 40k Chaos Space Marines guide

Doom Harbinger abilities attack an enemy’s leadership. Despair interferes with their ability to act cohesively on the battlefield: if you choose the Paralysing Insanity Despair effect on turn 4 it will strip the Objective Secured ability from enemy units within Dread Range.

Darkness protects Knights under its pall: if you choose the Gheist Storm on turn 2, enemies within Dread range must pass a Dread test, or else be restricted to shooting at only the closest Chaos Knight unit and halving the distance they roll when charging.

Warhammer 40k Chaos Knights guide - Author photo showing a Chaos Knight Acastus Lancer model

Chaos Knights Tactics

Chaos Knights bring soul-crushing individual power to the battlefield. The Tyrannical Court and Corrupted Heirlooms stratagems allow you to turn several Knights into truly monstrous characters armed with lethal warp-tainted artefacts, and the Arch-Tyrant ability grants your Warlord an additional Warlord Trait.

Combine that with a Favour of the Dark Gods, and your knights will each be a nightmarish bastion of power. This will be the smallest, most violent army possible – vulnerable in objective-based games but mind-shatteringly powerful in straight-up combat.

Sons of Barbarus: Read our Warhammer 40k Death Guard guide

With the proliferation of new War Dogs and the aura abilities of Abhorrent-class Knights, a pack of wild hounds can be extremely effective. The relic Helm of Dogs turns a War Dog into a leader among its vile kin, increasing its attacks and projecting its own aura that grants nearby War Dogs re-rolls on to-wound rolls of 1.

The many Favours of the Gods and Stratagems have lower costs for the small War Dogs; why not turn a Brigand into a Warp-Borne Stalker that teleports onto the battlefield from reserves?

Warhammer 40k Chaos Knights guide - Author photo showing a Chaos Knight War Dog Moirax

Alternatively, you could double-down as a Harbinger of Dread and suffocate your enemy beneath and inescapable shroud of debuffs.

House Korvax is your pick here, able to choose an additional Harbinger ability to take effect for its army once per game, as well as the Lord of Dread Warlord Trait, which enhances the range of their Aura abilities and Dread.

Transhumanity: Our guide to Warhammer 40k Space Marines

A Knight Abominant with the Vortex of Terrors psychic power, meanwhile, can reduce an enemy unit’s leadership and force them to pass a Dread test or suffer a reduction to their Weapon Skill and Ballistic Skill.

The Aura of Terror Warlord Trait forces enemies within Dread Range to take morale and Dread tests by rolling an extra d6 and discarding the lowest result, while the Traitor’s Mark relic both shreds enemy morale while they are in Dread range and grants the bearer the benefit of an additional Harbinger ability that the army has not selected.

Warhammer 40k Chaos Knights guide - Warhammer Community photo showing Chaos Knights models fighting Black Templars

How to start collecting Chaos Knights

Every Chaos Knight model is a massive investment of money, time and prayers to the dark powers. Start your army with a kit that you want to spend hours with, not what the internet says is the most competitive. As with any other Warhammer 40k unit, be wary: by the time you’ve built it, the meta may have shifted to favour something else.

There are now four dedicated Chaos Knight model kits (plus a variant of a loyalist Knight with resin upgrade parts sold on Forge World) but you must still raid Imperial supplies to construct a Knight Despoiler, Knight Tyrant, or the Executioner or Huntsmen War Dogs.

This is a perfect excuse to massively convert your army. Kromlech, Bitspudlo and many 3D modellers produce conversion bits to transform loyalist Knights into traitors – and neodymium magnets, a modelling saw and drill will allow you to magnetise weapons and get more value out of each kit.

Army in a box: Our guide to Warhammer 40k Combat Patrols

It’s also worth noting the Chaos Knights Army Box linked above packs the Codex, the Knight Abominant and two War Dogs. It was a limited edition and is in short supply these days – but it’s the best way to start an army – if you can find it in stock.

With thanks to 40kSteve for his lightning-wreathed Knight Desecrator, Medrengardian Knight Tyrant and lurid pink War Dog, Alex Morris’ sinister, converted red and blue Dread Household, and Gonders for his rune-etched Khornate Knight Desecrator.