The Horus Heresy was a struggle between the most powerful heroes and villains of their age– a clash of demigods upon the worst battlegrounds imaginable. And while the backdrop is a galaxy in flames, the most iconic moments of all are those epic duels between brothers and rivals.
Whether it’s two Primarchs trading blows while their Legions battle around them, or lone Captains bitterly locking blades in some forgotten cratered wasteland, these are the points around which the entire saga hinges.
Up until now, these confrontations weren’t really replicable on the tabletop – sure, the Primarchs have impressive stats and loads of special rules, but while they could certainly knock lumps out of one another, they hadn’t been duelling. Until now.
The new Challenge sub-phase makes these into the pivotal confrontations they should be. Broadly speaking it works like this:
This is an extra step in the Assault Phase. In your turn, you may issue one challenge per combat, as long as a character is involved.*
Your opponent may then accept – in which case they nominate a champion – or they may refuse. If they do, one of their “heroes” sheepishly steps back from the combat, and their cowardice is rewarded with a hefty penalty to their combat ability that turn.
Only models with the Command or Champion sub-types may issue and accept challenges. Champions are heroes whose main job is to take on these challenges, while Command models also bring other benefits to units, like helping them pass Advanced Characteristic checks.
If the active player declines to issue a challenge, their opponent may initiate a duel themselves, via the Heroic Intervention reaction.

Once the challenge is accepted, the two combatants are then separated from the wider fight and face off.
Starting with the active player, both players choose a Gambit for their champion. There are plenty to choose from, representing ways in which your warrior might approach the coming throwdown. There are nine universal Gambits, which offer defensive and offensive boosts, as well as several that are unique to Legions and characters. The Emperor’s Children are excellent single combatants, but the World Eaters' are more about carving up not only your immediate opponent, but anyone else foolishly standing nearby…

CORE GAMBITS
Seize the Initiative – If this Gambit is selected, then the Controlling Player may roll an additional Dice in the Focus Step and discard the Dice with the lowest result before determining the total.
Flurry of Blows – If this Gambit is selected, then the Model controlled by the Player that selected this Gambit gains a bonus of +D3 to its Current Attacks Characteristic, but any Hits inflicted by these attacks have their Damage Characteristic set to ‘1’ and this may not be modified by any Special Rule (including Shred (X) or Critical Hit (X)).
Feint and Riposte – This Gambit may only be selected by the Player choosing the first Gambit in the Face-Off Step. Once selected, the Player that selected this Gambit may name any one other Gambit (including Faction Specific Gambits that the Player does not have access to) and the Opposing Player may not select that Gambit in this Face-Off Step.
Finishing Blow – If this Gambit is selected, then the Controlling Player must roll an additional Dice in the Focus Step and discard the Dice with the highest result before determining the total of that Focus Roll. However, a Model for which the Finishing Blow Gambit has been selected gains a bonus of +1 to the Strength and Damage Characteristics of all Hits inflicted in the Strike Step.
Once your Gambit is selected, make the Focus Roll. The order of striking is usually decided by the Initiative – a significant advantage. Not so in a challenge!
Instead, both players roll a dice, adding their Initiative and any modifiers from Gambits, wargear, special rules or the support of nearby troops. There are penalties if your character is wounded or wearing especially heavy armour. The winner of the roll gets an extra attack and strikes first.

DUELLIST’S EDGE (X)
Some weapons are designed for use in personal challenges rather than the vulgar press of battle. Often light and perfectly balanced, they provide a key edge in duels and bouts of honour.
A Weapon with the Duellist’s Edge (X) Special Rule grants a bonus to Focus Rolls in Challenges.
In Step 3 of the Challenge Sub-Phase, the Focus Step, if a Player has declared that the Model under their control will use a Weapon with the Duellist’s Edge (X) Special Rule or has the Duellist’s Edge (X) Special Rule, then that Player gains a bonus equal to the value of X on the Focus Roll.
Certain weapons are better in a challenge than others. Anything that increases your initiative is very useful, such as the power lance, while weapons with the Duellists’s Edge (X) special rule add the value of X to the roll.
The Charnabal sabre is a consummate duelling weapon, offering an effective +2 to the roll, with a bonus to Initiative and Duellists’s Edge (1). It’s less lethal than a powered blade, however, so you will likely strike first – but you might not pierce armour as effectively.

CHARNABAL SABRE
IM | AM | SM | AP | D | Special Rules | Traits |
+1 | A | S | - | 1 | Breaching (6+), Duellist’s Edge (1) | Charnabal |
The Black Sword of Sigismund is a prime example of exquisite artificer weaponry, boasting Duellist’s Edge (2) alongside a profile to make any opponent worried.

THE BLACK SWORD
IM | AM | SM | AP | D | Special Rules | Traits |
I | A | +2 | 2 | 1 | Critical Hit (6+), Duellist’s Edge (2) | - |
Perhaps the standout duelling weapon in the game is the White Tiger Dao wielded by Jaghati Khan. This lightning blade increases his already impressive Initiative to 9 (higher even than Fulgrim), and with Duellist’s Edge to boot he is all but guaranteed to land the first blow.

THE WHITE TIGER DAO
IM | AM | SM | AP | D | Special Rules | Traits |
+2 | A | S | 2 | 2 | Impact (AM), Duellist’s Edge (1) | Power |
There is a fair amount of nuance and flavour to these rules, making them great for an epic narrative moment with tactical combat choices. These duels are worth enjoying – and they’re fought over several rounds until one party is dead or manages to withdraw.
Over the next few weeks, we’ll be pitting some of the heroes of the Horus Heresy against one another in duels over on our social media pages. Let us know what face-offs you would like to see. We’ll be back tomorrow with more lore of the Horus Heresy, while we’ll touch on the Force Organisation Chart – which is still very much with us – on Wednesday, and vehicle rules on Friday. Yes they’re tougher, and no we haven’t changed how it all works.
* It’s not mandatory at this stage to utter a contemptuous challenge or besmirch the honour of your enemy, but it would definitely help.