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The Horus Heresy Beginner’s Guide (Age of Darkness)

Warhammer: Horus Heresy is a miniature tabletop wargame published by Games Workshop.

In many ways, it’s a lot like Warhammer 40,000: It takes place in the far future, there are Space Marines and tanks all over the place, and you move miniatures around on a table and resolve their conflicts by rolling dice and consulting vast tomes of rules.

But, Horus Heresy is also something else: unlike Warhammer 40,000, which is a wide open space for the imagination to run wild with different campaign ideas and paint jobs for your miniatures, Horus Heresy is a bit more like a historical wargame in the sense that it takes place within a clearly defined timespan with specific events and characters.

This means that your battles are often a kind of reenactment of events you’ve already read about in lorebooks or novels from the Horus Heresy setting, and many hobbyists spend ages on providing their armies with the right heraldry and details for units taking part in a specific battle.

Rules-wise, Horus Heresy is also quite different from the current (9th) edition of Warhammer 40,000.

  1. Horus Heresy is primarily about Space Marines fighting Space Marines (more on that below), so Orks, Necrons and Aeldari aren’t the focus of the game. You can play non-Space Marine armies, but most of the time, you’re facing opponents with armies that look a lot like your own, but with different rules, characters and wargear options.
  2. The game’s rules are inspired by older versions of Warhammer 40,000, making it a bit slower and more detailed, with more rules you have to remember and appendices of special rules to consult, but that fits the historical wargame simulation style pretty well, so if you’re not afraid of really big rulebooks and a larger focus on narrative than the current high competitive style of Warhammer 40,000, Horus Heresy might be just the game for you.

In this guide, we go through the backstory of the Horus Heresy game, what you need to buy in order to play, and the basic principles of how the Wargame Warhammer: The Horus Heresy Age of Darkness plays.

If reading this leaves you with an urge to get into the game, the next step would be to go to our Horus Heresy Faction / Legion / Army Overview and guide for all the Space Marine Legions in the game to figure out which legion is the one for you.


Horus Heresy takes place before Warhammer 40,000, about 10,000 years before it in fact, but it still takes place in our far future.

In Horus Heresy’s version of our future, humankind colonised the galaxy after depleting most of the Earth’s resources, and untold billions of humans lived among the stars for thousands of years.

Then, two horrible things happened:

  1. The artificially intelligent machines which had helped Mankind conquer the stars turned on their masters, which led to centuries of war against the machines, and afterwards, humanity banned the use of artificial intelligence and took a big step down the technological ladder in general.
  2. A catastrophe of supernatural warp storms spread out across the galaxy and isolated all the Mankind-controlled worlds from each other, leaving room for alien civilizations to swoop in and retake the worlds they’d lost to the humans. A long era followed where each world had to fend for itself, and Earth became a post-apocalyptic hellscape of cults and techno-barbarians fighting over the last resources.

After centuries of darkness and destruction, a leader of Mankind finally emerged (apologies for the fascist overtones in the story here – remember that mankind aren’t the good guys in this fictional universe!).

He was called the Emperor of Mankind, and he swiftly united humanity under his rule, stomping out superstition and tyranny everywhere he went. When Earth was united, the warp storms stopped, and the Emperor embarked on a Great Crusade to reunite all the lost worlds of Mankind in a new Imperium.

To aid him in this Great Crusade, the Emperor created the Space Marines – genetically engineered superhumans who were nearly immortal as well as strong enough to carry power armour, bolters and all kinds of other technological marvels inspired by the ages before the Darkness while steering clear of robots and AIs.

He also created 20 Primarchs, which were gene-altered clones even more superior than the Space Marines, to be his sons and aides in governing the galaxy. Unfortunately, while the creation of the Space Marines went just as planned, a strange disaster whisked away the Primarchs just as they were born, and it took many decades of the Great Crusade to find them again.

Each Primarch had now grown up on the planet they had mysteriously disappeared to, and the hardships of their environments had changed them in different ways: Magnus had become a powerful psychic sorcerer, Angron was a deeply damaged super killer who had grown up in gladiatorial arenas, and so on.

Under the leadership of the Emperor and the Primarchs, the armies of Mankind reconquered most of the galaxy – but then, after a particularly great defeat of an alien empire on the planet Ullanor, the Emperor suddenly announced that he was withdrawing to Terra (Earth) to pursue a great, secret project.

In his stead, he promoted his most favoured Primarch son, Horus Lupercal of the Luna Wolves legion, to Warmaster of the Great Crusade.

It basically all went downhill from there.

What most inhabitants of the Imperium didn’t know was that behind the world they could comprehend with their intellect and their senses, a different world existed called the Immaterium or the Warp, and within that Warp, the Forces of Chaos resided.

The Forces of Chaos were twisted images of the emotions and thoughts of living beings, and they gain power the more those emotions and thoughts are nurtured. Out of these emerges the Chaos Daemons and the Chaos Gods, horrific beings of terrible power threatening to engulf all of reality in their madness.

The Emperor, of course, knew all about this, and his secret project on Terra had something to do with keeping the Warp from spilling out into reality, but most of his subjects, even the Primarchs, had no knowledge of the full extent of the Ruinous Powers.

Some Primarchs were tempted to grab for some power of their own by courting the Chaos Gods – first and foremost the religious zealots of the Word Bearers Legion, and before anyone could stop it, Horus the Warmaster himself had slid into the embrace of Chaos.

Horus had come to believe that the Emperor had abandoned his sons and kept the truth of the Warp from them, and he started harboring sentiments of resentment and revenge against his father (can you blame him, really?).

After many years of preparation, Horus let his rebellion break out during a battle on the planet Isstvan III, and over the next couple of tumultuous years, a full-scale galactic civil war split the Space Marine Legions into two camps, with half the Primarchs swearing allegiance to Horus, and the other half staying loyal to the Emperor.

Some chapters of each legion chose to defy the allegiance of the rest of their legion, but in general, the loyalist legions were:

  1. The Ultramarines
  2. The Salamanders
  3. The White Scars
  4. The Iron Hands
  5. The Dark Angels
  6. The Space Wolves
  7. The Raven Guard
  8. The Blood Angels
  9. The Imperial Fists

The legions who rebelled against the Emperor were

  1. The Sons of Horus (formerly the Luna Wolves)
  2. The Word Bearers
  3. The World Eaters
  4. The Death Guard
  5. The Night Lords
  6. The Alpha Legion
  7. The Iron Warriors
  8. The Emperor’s Children
  9. The Thousand Sons

The Horus Heresy war raged across the galaxy, and there were great victories and humbling defeats on both sides. The traitor legions tore down the barriers between reality and the Warp, and the daemonic horrors that the Emperor had hidden from his flock swarmed out across the galaxy, consuming worlds and corrupting the hearts of Space Marines and humans alike.

In the end, the war culminated with an apocalyptic siege of Terra itself led by Horus. In the final hours of the Siege, Horus fought his father in close combat, and he mortally wounded the Emperor before he himself was slain, and the traitorous Primarchs who survived the war retreated into the Warp.

Games of Warhammer: Horus Heresy take place between the beginning of the rebellion and the final hours of the Siege of Terra, based on the lore you can read in the game’s rulebooks, as well as the incredibly detailed account of the war that you can find in Black Library’s Horus Heresy series of novels, which at the time of writing this article consists of more than 40 books.

You definitely don’t have to read them all to play Horus Heresy, but Dan Abnett’s Horus Rising is the first in the series. It’s a genuinely great science fiction novel that even someone who is not a fan of Horus Heresy would enjoy, and it sets the scene of the 31st millennium pretty perfectly, so if you like reading science fiction, give it a go. They are on Audible if that is your thing.

Horus Rising: The Horus Heresy Book 1
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Some battles of the Heresy have specific scenarios, rules and even special units tied to them, which can be downloaded for free on the Warhammer Community site, and some have rules in campaign books for the game, but you can also absolutely make up your own minor battles or play counterfactual historical scenarios where a Primarch has switched sides or whatever your imagination comes up with.

However you choose to play, the lore of the Horus Heresy is extremely detailed and full of dramatic rivalries and betrayals, so if you like playing narrative wargames with a very high level of detail, it’s one of the best and biggest fictional game universes out there.

What do you need to play Warhammer Horus Heresy Age of Darkness?

We’ll get into the details of building an army a bit further down in this article, but to simply play the game at all, you need the following items:

Horus Heresy: Age of Darkness Rulebook
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The Age of Darkness Rulebook

The Horus Heresy Age of Darkness Core Rulebook for the game, containing all the lore and the basic rules for the game – but no full rules for any units at all. It’s a monstrous tome, and pretty expensive, but you need it and it’s also really pretty and full of lore and art to inspire your battles. You can buy a copy of the rulebook or you can get it via the Horus Heresy Starter Set.

Liber Imperium Army Book
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Liber Astartes Loyalist Army Book
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Liber Hereticus Traitor Army Book
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Liber Mechanicum Army Book
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Your faction’s army book

If you’re going to play Space Marines, you either need the Liber Astartes Army Book, which has all the rules you need for playing any of the 9 loyalist Space Marine Legions, or Liber Traitoris, which has all the rules you need for playing the 9 traitor Space Marine Legions.

If you’re into any of the non-Space Marine Imperial factions, the book you need is Liber Imperium, and if you’re playing the Mechanicum forces of Mars, you need Liber Mechanicum.

All of these are massive books, but most of the time, you only need the core rulebook and one of these army books, and you’re good to go rules-wise.

D6 Dice Set
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Like most Games Workshop games, almost everything in Horus Heresy is resolved using six-sided dice. Having around 50 of them is enough for most situations. You also need at least one scatter dice, which are used for figuring out the direction of grenades bouncing and similar situations.

If you don’t have the one from the starter set, they’re easy to find online.

Tape Measure Citadel
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Measuring Tape

Distances in Horus Heresy are measured in inches, and the battlefield can get pretty big, so an extendable tape measure is a must-have.

Games Workshop and other gaming companies have released multiple tape measures you can buy, but one from the supermarket is just as good.


Horus Heresy uses transparent templates for measuring the blast radius of grenades and the targeting area of the torrent of a flamethrower.

There are three templates in total, and if you don’t have the starter set (see below), you can buy them from all sorts of hobby shops. The starter set also comes with red plastic measuring sticks, but you can replace them with any other long object.

The Horus Heresy: Age of Darkness Starter Set
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Miniatures for Horus Heresy

Finally, you need some models to represent your army.

This is at once more simple and more complicated than most other Games Workshop games.

More simple, because a lot of the time, you just need to assemble and paint tons of Space Marines with slight differences in their weapons and wargear. More complicated, because many special units, characters and optional bits are released by Games Workshop’s frankly puzzling sister company Forge World, which releases its models in highly detailed resin rather than plastic.

Resin can’t be glued together with plastic glue at all (you need superglue for it), can bend out of shape during transport, needs to be washed and sanded before use (remember to use a mask!), is more fragile than plastic, and is also much more expensive, so it will be a turnoff to many hobbyists. Luckily, Games Workshop is taking over more and more of the production, so all the basic stuff such as marines, terminators, dreadnoughts and tanks are now in plastic.

If you want a surefire way to have what you need to play the game, you can also just buy the “Age of Darkness” starter set, which features everything mentioned above, except for an army book, as well as 2 Praetors, 1 Spartan Assault Tank, 40 MKVI Tactical Marines, 10 Cataphractii Terminators an a Contemptor Dreadnought, all in plastic.

If you’re planning on playing Space Marines, there’s no reason not to get the starter set – it’s a really good value.

If you start seriously playing games, you also need a game board and some terrain, but if you leave near a big town, there’s a good chance you can find a hobby store or a gaming club which has tables with terrain already set up for you to play at.

The Basic Rules of Horus Heresy: Age of Darkness

Very, very simply put, a game of Horus Heresy is about fielding an army of models against your opponent’s army of models on a battlefield with specific mission instructions for how you win the mission.

You take turns moving your armies, roll dice to determine the outcome of fighting and shooting, all to simulate a glorious battle between heroes and villains in the grimdark future. In order to simulate all this, the game uses a long list of different statistics and characteristics to show different units shoot, move, fight and react to different conditions. Before we go into how to play the game turn by turn, the next section goes through all the different kinds of characteristics that show up in the rules for your units and characters.

Characteristics and Stats in Warhammer Horus Heresy

If you’re used to playing Warhammer 40,000 or Warhammer Age of Sigmar in their current edition, the first thing you’ll notice when you browse the rules is that Horus Heresy has unit profiles rather than actual datasheets/warscrolls.

In short, this means that the entry for each unit doesn’t have all the rules you need to know how to play that unit – not the stats for your weapons, not a description of its special rules or anything like that. Instead, the names of its weapons and rules are mentioned, and you’ll have to look them up in appendices in the rulebooks. This can feel completely insane at first, but at least in theory, this is actually a streamlining of the rules in the sense that a bolter works the same for all units, if a unit is good at controlling objectives, it has a rule for that which is the same as the rule all other units with that ability has, and so on. It takes a bit to get used to, though, since there is a lot to memorize, even if you’re not counting Legion-specific rules.

Editor’s Note: Wow, I completely forgot that was how 40K worked back in the day. No wonder I could never get into it back then!

What you can memorize pretty easily, however, is the statline of 10 different statistics that represent any type of unit you can field, represented with the abbreviations M, WS, BS, S, T, W, I, A, Ld and Sv at the top of each unit profile.

Let’s have look at what they are, and what they do:

  • M is Movement: This is simply the amount of inches your models can move in a single movement phase. Like everything else in the game, there are tons of different types of moves (withdraws, charges, surge moves and so on), but this is the basic movement value of your model. Standard Tactical Marines, which is the type of model you see the highest number of in most legion vs. legion games, has a Movement of 7.
  • WS is Weapon Skill: This represents how good your model is at using melee weapons. You use this statistic in melee combat when you’re the attacker and when you’re defending. To figure out if you hit an opponent with a melee attack, before rolling any dice, you consult a table in the core book (or on the reference sheet that comes with the starter set).

    Looking at this table, you check your own Weapon Skill against the Weapon Skill of the defender and check the table to see what number you have to match or roll above with the dice for your attack.

    So, if a standard Space Marine with a Weapon Skill of 4 attacks another standard Space Marine with a Weapon Skill of 4, the attacker hits on a roll of 4 or more. If the attacker had had a Weapon Skill of 5 instead, it would have hit on a roll of 3 or more, and so on. Weapon Skill kan be a number from 1 to 10.

    If you’re coming from one of the other two current Warhammer tabletop games, it can be difficult to remember that your Weapon Skill isn’t just the number you have to beat, and that having a higher Weapon Skill is actually better in Horus Heresy as opposed to in Warhammer 40k, but as with most other things in Horus Heresy, it’s technically a better simulation of close combat than doing it the other way around, since it simulates two skilled fighters dueling, rather than just simulating someone trying to hit a stationary object.
  • BS is Ballistic Skill: Ballistic Skill shows how good your model is at hitting targets with a ranged weapon such as a bolter. Again, it isn’t just a number that shows what you have to roll to hit the target. Instead, you check your Ballistic Skill value and consult another table in the rules to see what you have to roll to hit with your ranged weapon.

    If you’re a standard Space Marine, you have a Ballistic Skill of 4, so you hit on 3s or more. The higher your Ballistic Skill, the lower you have to roll to hit. If you have a Ballistic Skill of 6 or more, you get to reroll a roll 1 of, but with a worse chance to hit. Basically, your chance to hit is 7 minus your Ballistic Skill for Ballistic Skills of 1 to 5, and for Ballistic Skills of 6 to 10, you hit on a 2 or more, and your rerolls get better and better the higher Ballistic Skill you have. It’s a lot of numbers, but manageable to memorize.
  • S is Strength: Strength is used to figure out if you wound a target, mainly in melee, since ranged weapons have their own Strength values. You have to both hit and wound an enemy target in order to damage it. For this, you consult another table in the rules. If a Marine with a Strength of 4 tries to wound a Marine with a Toughness of 4, you have to roll a 4 or higher to hit.

    The interesting thing about this table is that Strength values from 1 to 6 have Toughness values against which they can’t wound at all. This is pretty cool for a game of sometimes superheroic combat, since it lets the game simulate that some really big characters and machines just can’t really be hurt by ordinary people. Some melee weapons apply bonuses to your Strength value when using them.
  • T is Toughness: As explained above, a higher Toughness makes you harder to wound.
  • W is Wounds: This is basically your hit points. Your number of wounds is how many times you can be wounded without being killed.

    Most ordinary models have a wound value of 1, which makes sense since Horus Heresy weapons don’t have damage values, so when you hit something, it generally just dies, and a lot of what is simulated through damage values in 40k is simulated through Strength and Toughness as well as special rules in Horus Heresy. Again, tons of exceptions apply, of course (see Vehicles and Characters below), but this is the basic principle.
  • I is Initiative: Initiative is a bit more complex than the statistics previously mentioned here, since it is used for a couple of different things. It indicates how fast your model is (which, apparently, is different from how far it can move).

    In close combat, Initiative values decide which models attack first (more on that below), but Initiative is also added to your Movement characteristic if you decide to Run with a unit in the Movement Phase, among other things.
  • A is Attacks: It tells you how many attacks you have with a model in close combat. Often, this value is just 1. It doesn’t determine how many attacks you have when shooting.
  • Ld is Leadership: This determines the mental fortitude of a model, and it is primarily used for Morale checks. When a unit takes a lot of casualties (25% of its total amoun of models in a single phase) or loses a close combat by suffering more wounds than it inflicted, it has to make a Morale check. This is done by rolling 2 six-sided dice (2D6 in the game’s terminology).

    If the total of the two dice rolls is equal to or less than your Leadership, you’re okay, but if it is more than your Leadership, your units has to Fall Back. Falling Back is basically a “run away!” move where you you run 2D6 inches towards your own edge of the battlefield until you have a chance to pass another Morale Check to regroup and get back in the fight.
  • Sv is Save: If you’re used to playing Age of Sigmar, this is, for once, a statistic that works like you’re used to! Save is a number value with a + behind it, and it is simply the value you need to roll equal to or higher than when you roll a Save roll to see if you can avoid taking any wounds from an attack. The lower your Save characteristic, the better, but it doesn’t go lower than a 2+.

Weapon Profiles in Horus Heresy

Weapons in Horus Heresy have their own statline like the one for models discussed above, but it’s a lot simpler and pretty easy to remember:

  • Range: This is how far away targets for this weapon can be. For melee weapons, it’s usually “-“, which means it can only be used in close combat, but otherwise, it’s a value in inches, such as the 24” range of a bolter.
  • S: This is Strength, just as explained in the section above. It can be a number, or it can say “User”, which means it uses the Strength of the model carrying the weapon.
  • AP: This is Armour Piercing, meaning the weapon’s ability to ignore the armour of its target. In Horus Heresy, the value of your AP, which could be 5, for example, signifies the Save characteristics this weapon completely ignores, so the lower the value, the better.
  • Type: This is where it gets a bit complicated: All ranged weapons are 1 of 7 types:
    • Assault weapons can be fired in the same turn as the model carrying it makes a charge move
    • Heavy weapons can only be fired as if having Ballistic Skill 1 if you moved in the same turn you fire them
    • Ordnance weapons can’t be used after moving at all unless they’re mounted on a Vehicle
    • Pistol weapons are like Assault weapons but can also be used as close combat weapons and be dual-wielded for extra attacks
    • Rapid Fire weapons can be fired twice in an attack if they are within half of their maximum range of the target
    • Bombs are single-use weapons unique to Flyers and can only be fired in the Movement phase
    • Destroyer weapons are like Assault weapons but can cause extra damage and armour penetration to Vehicles.
    • Melee weapons are just Melee type, and on top of that, both kinds of weapons can have all sorts of Special Rules (which are far too numerous to mention here – we might do an article on these in the future), which is also something most models have. These have to be looked up in the core rulebook and in the appropriate army book for your legion.

Unit Types in Horus Heresy

Different types of units in Horus Heresy behave very differently. This is one of the elements of the game that makes it really different from Warhammer 40,000, and there’s far too much intricacy in the different subtypes and unit types to cover it all here, but to give you an idea of how it works, these are the main unit types and their function:

  • Infantry: This is the baseline that the game’s rules are written for, and the standard that other unit types deviate from. Units of Infantry can consists of all sorts of soldiers on foot, and infantry units can also be joined by characters and even Primarch, as long as the models it consists of are on foot.
  • Cavalry: This type consists of anything that rides a mount, be it a motorbike or a real horse. They resist the negative effects of terrain in different ways, can’t be pinned and move fast when falling back.
  • Automata: These are robotic machines that can’t get scared and who resist poison and other effects you need an actual body to be affected by. They can’t make Reactions (see below).
  • Dreadnought: These are huge machinic walkers that are as resistant as Automata, but they can also fire all the ranged weapons in each Shooting phase, among other bonuses.
  • Daemon: These are daemonic horrors summoned to the battlefield, and as such they get worse as the game progresses, losing their connection to the Warp. They cause Fear and are immune to it, among other effects.
  • Primarch: Primarchs are the superhuman leaders of each Legion, with a ton of special rules, who can’t have their characteristics debuffed by other units, and they are always the Warlord of your army if you’re fielding a Primarch.
  • Vehicles: Vehicles are the unit type that behaves the most unlike other types. For starters, they have their own statline:
    • Movement (M) works more or less like for regular models
    • Ballistic Skill (BS) also works as described in the above section
    • Armour has three subcharacteristics, allowing the vehicle to take more or less damage from different directions, which is a huge change from other GW games as it makes positioning and facing of your units really important:
      • Front (F) is the armour on the front of the vehicle
      • Sides (S) is the armour on both sides of the vehicle
      • Rear (R) is the armour on the back of the vehicle
    • Hull Points (HP) is the health pool of the vehicle
    • Type is where all the Special Rules are located for a Vehicle.

      Vehicles take damage differently: You have to roll armour penetration rolls to beat their armour value, and there’s an amazing Vehicle Table that you roll on to trigger all sorts of effects when they’re damaged in certain ways, which can lead to anything from scaring the crew to the Vehicle exploding and damaging nearby units!

      Vehicles have 18 pages of rules in the core book, so let’s just keep it at:

      They move, attack, behave and die differently from everything else, which leads to a lot more variety in the game experience as opposed to modern 40k, where vehicles are mostly just big models with some extra rules. And we haven’t even gotten into crucially different subtypes such as Flyers or Titans! Horus Heresy might be about Space Marines fighting Space Marines, but it’s also very much a game about big machines.
  • Characters: These are actually a subtype, but a very special one with pages of rules in the core book. Being a narrative game in many ways, Horus Heresy puts a lot of emphasis on interesting individuals in its game rules. Characters can be many things, from the sergeants of infantry squads who are always part of a unit to Leaders with specific names taken from the Horus Heresy novels.

    They can be part of units, so that your Praetor warlord, for example, can be embedded in a squad of Space Marines, but when damage is allocated to that unit, you can choose for it not to be allocated to the character (so the squad acts as a kind of extra armour for your character). One of the coolest things about the Character rules is Challenges.

    Once per combat, a character can issue a challenge, and the opponent can then answer the challenge with one of their characters locked in that combat. Those two characters then duel, and keep fighting in the following combat phases until one of them goes down or some special rule allows them to escape. This is an excellent way of creating drama within the game.
  • Psykers: This is also a sub-type, but it’s worth mentioning as the final entry on this list anyway. Psykers are Horus Heresy’s wizards, wielding the powers of the Warp to create horrors and wonders on the battlefield. Unlike other games with entire game phases for magic attacks, Horus Heresy simply treats many psychic powers as weapons, and otherwise, their powers are just carried out in other game phases.

    Otherwise, two important things to know about psykers is that, unlike in other GW games, they get access to everything in the Psychic Discipline (magic school equivalent) they belong to, rather than just one or two powers, which is fun, and they can suffer Perils of the Warp, which basically means psykers take damage if they fail casting their powers badly.

In addition to all of this, units can also be faction-specific, and many models have a couple of options to choose from for their weapon loadouts.

So much of the charm of Horus Heresy is in the customizability of your forces: no army has to be the same as the one your opponent is fielding, and if you have a fun thematic idea for your army, there’s probably a way the rules can allow you to build that.

To get a taste of the diversity of units and rules in the game, go take a look at our Faction/Legion Guide for the game.

The Phases of a Game in Horus Heresy

While there are the usual Games Workshop game modes in Horus Heresy – Open Play where there isn’t much structure, Narrative and Campaign Play where you’re playing through a story (which is the default mode in Horus Heresy, and competitive Matched Play, they all have the same basic game structure in common:

After setting up your armies and battlefield and selecting a mission (there are 6 to choose from in the core book and many more in supplements and expansions), each game is played in turns that each contain the following phases.

Movement Phase

For rules purposes, there’s technically a phase before this one called “The Start of the Active Player’s Turn”, but that’s just so that special rules and stuff can happen before anything else happens.

The Movement Phase is the first real phase, where the active player gets to move all of their units according to their rules. Movement can be affected by difficult terrain, giving a -2 to the Movement of a unit passing through it, among other things. Units of several models have to stay close to each other during the move, so you can’t just scatter a unit across a large area.

Since direction and facing matters for hitting and damaging vehicles, you can also use your movement to pivot a model on the spot to change which way it’s facing.

Shooting Phase

The Shooting Phase is where the active player gets to shoot with ranged weapons from their units.

We’ve gone through how shooting works in the Basic Rules section above, but it should be mentioned that targets have to be in range and within line of sight, and that the game has rules for being in cover, as well as multiple ways a model can mitigate damage in addition to their Save characteristic, much like in Warhammer 40,000 or Age of Sigmar.

Assault Phase

The Assault Phase is the close combat phase of the game, and it is split into two sub-phases.

  • The Charge sub-phase is where units charge into melee range. This is done by rolling dice to see if you can charge far enough to reach your target. If you charge, you get +1 to your Attacks characteristic in the subsequent fight sub-phase.

    If you don’t roll high enough to reach your target, you get a Surge move, which is half the distance you rolled for your charge. If you can shoot and charge in the same turn, you can only charge the unit you shot at in the preceding phase.
  • The Fight sub-phase is where combat happens. When fighting, both players get to fight, regardless of whose turn it is. The order of who attacks when is determined by the Initiative characteristic of units in close combat range. If any models in a unit are not in base contact with the units they’re about to fight, they can make a Pile-In Move of up to 3″ to get into fighting distance.

    An interesting aspect of the Fight sub-phase is that players can win or lose an Assault: You win by being the side that dealt the most Wounds to the opponent, and the loser has to make a Morale check, so they risk Falling Back.

…And that’s basically it! For a game with so much complexity, it’s a nice touch that Horus Heresy keeps the structure of a game turn relatively simple. Of course, all sorts of exceptions and special rules can mix things up, but that’s also fun if the basic unaltered structure is easy to understand.

Reactions in Horus Heresy

One important aspect of Horus Heresy that does complicate a game turn in a big but fun way is Reactions.

Reactions are actions that a player can take when it’s not their turn. If you’ve ever been to a tabletop tournament and either experienced going out for takeaway while your opponent finishes their turn or seeing your opponent start to fall asleep during your turn as you move 40 Marines one at a time, there’s a good chance you’ll love this system.

A player can make 1 Reaction per phase of the game, and while each faction in the game has its own special Reactions, all players have access to the following Core Reactions:

  • In the Movement Phase, you can use a Reaction if the other player finishes a Move within 12″ of one of your units. You can use one of the following:
    • Advance lets one of your units move up to the value of their Initiative characteristic towards the unit that moved close to it. Vehicles just move 6″ inches and pivot instead.
    • Withdraw is the same, but you move directly away from the opposing player’s unit.
  • In the Shooting Phase, you can use a Reaction after an enemy unit has made a shooting attack and made all its rolls, but before damage is assigned to your unit. You can use one of the following:
    • Return Fire simply lets you shoot back at the attacker with the unit being shot at. This can be a pretty strong incentive for not shooting at a unit with really good ranged weapons.
    • Evade gives your unit the Shrouded (5+) Special Rule, which lets you roll an extra 5+ save roll against all incoming wounds for that one shooting attack being made against you.
  • In the Assault Phase, you can use a Reaction when an enemy unit declares a Charge against one of your units. You use your Reaction after they resolve their Charge rolls, but before they actually move the distance the Charge lets them. You can use one of the following:
    • Overwatch is like Return fire: You simply make a shooting attack against the charging unit.
    • Hold the Line lets you make a Morale Check, and if you succeed and the Charge succeeds, the enemy unit’s charge counts as Disordered, which means that unit doesn’t get +1 to its Attacks from charging. If the enemy doesn’t succed their Charge but you succeed your Morale Check, any other Charge from other units against the Reacting unit will also be Disordered.

Reactions add so much to the game.

Not only does it give you something to do when it’s not your turn (apart from eating snacks and fighting in the Assault Phase), but since you only have 1 Reaction per phase, the Active player can also try to bluff you into spending your Reaction at the wrong time, so that you might Return Fire on one attacking unit only to be gunned down by another unit afterwards with no options for retaliation.

How do you build an army in Horus Heresy Age of Darkness?

When you have selected which faction you want to fight as, its time to start building an army list, which means selecting what units you want to field in battle. This is done by balancing two elements: Points values and Detachments.

Each unit in the game, and much of the wargear they can equip, has a Points value, and for each game, you and your opponent decides how many Points you can each field. It isn’t unusual for that number to be around 3000, but you can start lower just fine.

Detachments are groups of units that make up an army. Each Detachment has some spots that you have to fill out, determined by Battlefield Roles. The Battlefield Roles in the game are:

  • HQ, which are the leaders and officers of your army
  • Troops, which are the core units of your army, usually infantry, which are good at claiming and holding objectives.
  • Elites are high quality fighters, often with specialised roles on the battlefield
  • Fast Attack are units made for scouting and maneuvering, or for getting close to the enemy as soon as possible
  • Heavy Support are heavy weapons squads and artillery made for doing maximum damage to the enemy, such as big tanks or cannons.
  • Fortifications are literally pieces of scenery you can field in your army, such as bunkers and walls.
  • Lords of War are super-mega units such as big Titan walkers.
  • Primarchs are the protagonists of your story, the sons of the Emperor and the leaders of their Legions.

A Detachment tells you how many of each Battlefield Role you have to field in that Detachment. Most often, you have to field an HQ and some Troops, but other Detachments are more specialized. In addition to that, a Detachment will also have some optional spots you can field for other Battlefield Roles, so you can fit as much as you can into a Detachment. You can also field Allied Detachments in your force, which are Detachments made up of units that are not from your own army (if you really want an instant headache, go check out the chart in the core book for which Legions can ally with which Legions).

When you’ve filled up your Points quota and put everyone in Detachments, you must also select a Warlord for your army. If your Primarch is in your army, he has to be the Warlord, but otherwise, it can be a Character or HQ model. That Warlord then gets a special rule called a Warlord Trait. Each army has special Warlord Traits, but to give you an idea of how they work, these are the three Warlord Traits all armies can take:

  • Bloody-handed gives a +1 to wounds caused in combats taking place within 12″ of the Warlord, and it also lets you perform one extra Reaction in the Assault Phase.
  • Stoic Defender makes targets of shooting attacks from the Warlord or the unit he is part of take Pinning Tests if they suffer any wounds from the attack, which means they risk becoming unable to move or shoot properly. It also lets you perform one extra Reaction in the Shooting Phase.
  • Ever-Vigilant lets the Warlord or the Warlord’s unit add the Warlord’s Initiative to its Run distance rather than the lowest Initiative in the unit, and then add 1″ distance to the Run on top of that. It also lets you make an extra Reaction in the Movement Phase.

To truly understand how to build your army, take a look at our Legion Guide (LINK) to see how each Legion builds its forces in its own way.

Final Thoughts on Warhammer: Horus Heresy Age of Darkness

Horus Heresy isn’t a particularly easy game to learn to play. There is a lot to keep track of, but if you’ve gotten this far in this article, chance’s are you don’t mind that.

Horus Heresy is a game for narrative geeks who love making a truly unique army full of character and interesting options, and the game really, really rewards that kind of thinking with its unified basic structure that you can then add almost unending modifiers and special rules on top of.

The gameplay itself is fairly conservative, and the fun of the game is pretty dependent on not just playing games where you have to eradicate your opponent – with all those different rules, tables, charts and rolls, that can become a bit of a slog, but if you play fun missions with a story and some interesting objectives, and then add interactive systems such as Reactions and Challenges into the mix, the game really comes alive.

It has to be said that even though the game is pretty complex and old-school, the rulebooks do a pretty good job at explaining and exemplifying its rules.

The Horus Heresy: Age of Darkness Starter Set
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We wouldn’t recommend anyone playing Horus Heresy as their first tabletop wargame, but if you’ve been playing Warhammer 40,000 or Warhammer Age of Sigmar and you feel like you’re ready for something with a deeper rule system (in many ways, its more akin to a large-scale Necromunda than anything else), Horus Heresy is ready for you to dive right into.

Finally, getting deeply involved in the lore is the best way to fall in love with Warhammer Horus Heresy.

There are so, so many books out there to read, and if you haven’t already, do yourself the favor of listening to Horus Heresy novels as audiobooks while you work or do hobby – the publisher, Black Library, has an amazing track records of hiring narrators with tremendous dedication to the stories and the universe they take place in, and even huge space operas such as Dan Abnett’s Horus Rising almost become audio dramas instead with lots of different character styles, accents and personalities.

This writer will never forget how it felt to finish that book, and then browse the Forge World webstore and realize he’d actually met the characters who were there as models ready for him to buy – in his imagination, at least.