Liber Mechanicum, up for pre order today alongside Saturnine is the Warhammer The Horus Heresy 3rd Edition Army Book containing the forces of the Taghmata Omnissiah, the military forces of the Mechanicum of Mars. This is part of our 3rd Edition Heresy coverage in which we take a look at all the books out today, the new edition itself and the awesome Saturnine box! For a full list of reviews up today be sure to check out our Heresy 3rd Edition page!

In this article we’ll be taking a look at the book, seeing what units are included, what they do and talking about some example army lists. We’ll also be doing some comparisons to the previous Mechanicum book, though keep in mind that this is a new edition, so like to like comparisons are not the most useful here

Massive thanks to Games Workshop for sending us over the new Horus Heresy releases to check out on the site. If you would like to support the site then why not pick up your copy of Liber Mechanicum through our affiliate Element Games and save yourself some money too?

We’ve also filmed a full deep dive into this book (and the other Liber volumes) which you can check out on YouTube or just below

So without further ado, let’s dive into the Liber Mechanicum

Liber Mechanicum – Warhammer The Horus Heresy 3rd Edition Revew

The new edition of Warhammer The Horus Heresy is here, and on day 1 alongside the Saturnine box we have the Liber volumes for (most of) the main factions up for pre order too. If you’re coming into 3rd Edition from 2nd then you know the drill here – These are books that contain all of the rules for a faction and their units (Much like a “codex” for those coming from 40k)

Last time around the Mechanicum book contained the rules for the Taghmata (The Mechanicum army) alongside the Questoris Knights and the Titan Legions. This time the Mechanicum have been split into their own book, with Questoris Knights and Titans being in Liber Questoris (which we have also reviewed today here)

So whats new here? Well, in addition to the core auxiliary detachments listed in the Core Rulebook, Mechanicum have a couple of new ones available to all Mechanicum armies, and a couple locked behind specific traits. We’ll look at these traits in a little more detail later, but essentially when selecting units for your army you have to select from which “faction”of the Mechanicum it has come from, with each faction offering a different trait, some new abilities and some unique detachements.

For the Auxiliary Detachments available to everyone we get a couple of new ones that make it much easier to construct forces given the lack of troops choices (again, more on this later…)

The first is the Taghmata Cohort which allows for 4 support slots without any restrictions – this is good as a lot of your infantry falls into this basket! Secondly we have the Apprentice Cadre which has 4 troops slots (one of which is prime) letting you cram even more Tech-priests into your army.

It may be a bit of a shift in thinking compared to the 2nd edition rules, but you’ll pick up the new detachment system in no time at all, and it’s really quite flexable.

One thing that’s worth pointing out here is that this army list represents the Mechanicum at the start of the Heresy – while there are Daemon Engines in the book for Traitor players to take, the Dark Mechanicum as it becomes doesn’t really exist yet – I’m sure this will be expanded in future books though!

So what about the units? Let’s take a look at the Taghmata Army List

Mechanicum Taghmata Army List

Archmagos

The High Command choice for the Mechanicum comes in two flavours – An Archmagos with or without an Abeyant. Stat-wise the Archmagos has been hitting the gym since 2nd edition, now rocking BS and S 6 with a mighty 6 wounds, and even Toughness 7 when on the Abeyant at the cost of a point of Initiative due to the size of the platform. Both have Battlesmith (4) making them very good at repairing robots, and with Master of Machines is able to join Automata units. With a lot of Mechanicum units unable to score (Automata cannot contest objectives) the Archmagos makes up for that with the Comptroller (2) rule, meaning it scores an additional 2 points when it claims an objective – though this will mean your HQ choices are going to be in the thick of the fighting.

The Abeyant is well worth picking up as it has the “Command Throne” rule which is used to reduce the cost of reactions by 1 – they are limited to doing this once per turn, but essentially gives you an additional Reaction Point every turn, which is very powerful this edition! Hopefully we see him come to plastic soon!

Archmagos Scoria

At the end of the book we get two profiles for some Traitor named characters based on the Forge World models currently available. First up we have Scoria, the scorpion like heretech himself. He always had a pretty good profile, and we get the same again here with decent stats and a whole host of special rules. Interestingly he is now the Walker unit type, which means he is going to be acting a little more independently than he is today!

Archmagos Draykavac

The other named character is Draykavac, who can be taken on or off his Abeyant. This guy is a lot cheaper than Scoria, but still has some pretty cool rules such as a unique gambit that fires a gun just before the challenge starts – the kicker is the weapon is Poisoned 2+ and can also reduce the enemy toughness and Strength by 1!

He also has a fun rule that allows him to do a cool test at the end of any turn – pass it and he can be removed from the board – he counts as destroyed by the enemy gets zero points for slay the warlord, which can be handy to get him out of dodge!

Magos

Making up two choices in the Command slots are the Magos and Magos on Abeyant. These function like a lesser Archmagos with pretty much the same rules but lesser stats (the Magos is only Battlesmith (3) for example). Where things get really useful however is with the Officer of the Line (2) rule. This makes it so that if you fill a Command slot with one you are able to add 2 detachments to your army rather than just one. This is really handy, especially in Mechanicum where you have lots of toys in different slots. Take two of these in a larger game and you have more than enough slots to put together whatever army you want.

Arcuitor Magisterium

The final Command choice is the Arcuitor Magisterium, our close combat specialist. With a decent WS of 6 and access to any Mechanicum melee weapon, this is now a dedicated fighter! She also has Infiltrate, allowing her to set up further down the board. With master of machines you can also stick her with some fighting robots like Scyllax or Domitars. Interestingly her Loyalty is also at question, as Traitors are now able to take her too!

Scyllax Guardian Maniple

First up in the Retine slot are the Scyllax – these have had somewhat of a glow up now boasting WS 5 and a base S of 5. Their combat array also hits at AP3 base making these things pretty nasty, especially when combined with their Rad Furnace reducing enemy toughness!

Echidnax Servo Maniple

At first I was excited because I thought this was a new unit hiding in Liber Mechanicum, but its actually the Servo Automata from the Tech-Priest kit given a new name. These are now a repair unit that can Battlesmith with increasing values depending on how many models you take in the unit. One thing to watch out for is that they can only function if there’s a model leading the unit

Domitar Battle Maniple

Moving on to the Elites slot and first up we have the Domitar. These were always cool, but I feel they are even better now rocking a 2+ save while still having a 5+ inv – They also have the Firestorm special rule which lets then Volley fire at BS, and they can even opt not to complete the charge after firing said Volley Fire! This is ace as essentially allows you to use them to make two shooting attacks a turn and then pause just outside of their charge ready to return with more volley fire the following turn when their target charges them back.

Myrmidon Secutor Host

The Myrmidons are back in the Elite slot, and despite now only having BS4 they are still pretty nasty. Again there’s a range of weapon options for them, but what’s really nice is their Implacable Advance rule gives them the ability to Volley Fire with any non-heavy weapons! There guys want to be wading into combat (especially as their squad leader now gains Feel No Pain while in a challenge!) so some extra shots on the way in is always a bonus! Oh and with the Champion Type, the squad leader is able to challenge too!

Myrmidon Destructor Host

Rather blow things up at a distance? The Destructors are still ace and pack some of the heavier weapons in the book. Both flavours of Myrmidon have Vanguard too, making them well suited at nuking things off objectives.

Decimator

Liber Mechanicum includes a couple of Daemon Engines, which was a nice surprise – they are gathered together towards the end of the book, but I’ll include them here for ease of reading.

The Decimator is essentially a Mechanicum Leviathan, but interestingly takes a Elite slot, which should make it easier to fit it in alongside other units.

Castellax Destructor Maniple

Moving on to the Heavy Assault squads we get the Castellax Destructors. Now there is another entry for vanilla Castellax later on in the book – these ones are your specialist heavy weapon carrying robots. They have dropped to BS 3 rather than 4, but they now have the “Armour Breaker” rule which means whenever they get a penetrating hit on a vehicle they inflict an additional point of damage on a 4+

Just like the Myrmidons they also get to fire all their guns when doing Volley Fire

Ursurax Cohort

Some of my favourite models with the worst rules of 2nd edition now get a well deserved glow up. They are now initiative 3 with a 3+ save, meaning they might actually get to punch things back this edition! With the standard claws they are getting 5 attacks each with AP3 and Breaching, finally making them scary – or you can swap any model’s claws for power fists for added punch. Their Volkite Incinerators are Assault weapons too, meaning they can Volley Fire on the way into combat too!

Blood Slaughterer

Our second Daemon Engine is in the Heavy Assault slot, and are now bought in pairs (a sign of a new model coming maybe?). The harpoon now has Phage which rather than making charges easier, actually reduces the target’s toughness. The base Slaughterer Blades are nice too with AP3 and Shred, Breaching and Reaping Blow making these pretty nasty.

Tech-Priest

So we have a really odd one in the only troops slot in Liber Mechanicum – the humble Tech-Priest! Now I suppose the idea here is to buy multiples of these to lead your automata units and allow them to score, and with Battlesmith and some decent advanced characteristics these guys will keep them in the fight too. Nice and cheap and probably worth picking up a couple of them each game. Hopefully this means we’ll get a nice new plastic kit with a few different varients.

Tech-Thrall Covenant

Moving on to Support we see most of our core units. The Tech Thralls have had quite some big changes making them more like a tar pit than they were before. Firstly they are now T5 which makes them hard to chew through! You can also take up to 40 of them in a squad now (if you can stomach building 40 of the models!) They are about twice as expensive in points than they used to be, but I think this is a decent trade off. They can’t do reactions or volley fire, but they do best at standing on an objective all day long in an endless horde!

Thallax Cohort

Next up we have the Thallax, and these are toned down a little from last edition, now only moving 10 inches and not able to move after shooting. They do however now have a 3+ save and with Aegis of Pain can also cause fear too! Their weapon upgrades are no longer limited to one in three, you can upgrade all of them if you want!

Castellax Battle Maniple

In the Support slot we also have the vanilla Castellax with Bolt Cannons, same statline as the heavy ones, just without the ability to upgrade their Bolt Cannons. One thing to keep in mind with these is that Automata my themselves cannot score objectives, so you’ll want to stick a Tech Priest with these chaps if you;re running Cybernetica.

Thanatar Siege Maniple

Returning for Liber Mechanicum in the War Engine slot is the Thanatar. They are a little slower now with movement 6, but pack 10 wounds each now making them much tougher to kill. As before they can be taken in two flavours, the Cavas or the Calix, with the Calix still being bananas good with 2 shots at S10 AP2 with armourbane and damage 4 if it stands still.

Amiger Moirax

The other War Engine choice in the book is the Armiger Moirax. They retain all the various weapon options they used to have, and hopefully at some point we get a plastic one added to the range! Special rules are stripped down, but otherwise a very similar profile to last time

Triaros Armoured Conveyor

The only transport we have in the book actually lives in the Heavy Transport slot, which makes sense as this is essentially a Land Raider. Still a solid armour 14 with a flare shield and now 7 HP this makes this a very tough shell to crack – though it’s going to need bonus slots or a heavy transport detachment if you want to take a few of them.

Vorax Attack Maniple

The only Recon slot in Liber Mechanicum goes to the Vorax, which interestingly are now taken in unit sizes of 2+ (a sign that we might be getting a new plastic kit containing two models maybe?) A nice little fast unit for harassing enemy units, though as its an Automata it can’t be used to grab objectives quickly.

Vulturax Stratos Squadron

Moving onto the Fast Attack slot, we get another contender for a new plastic model, the Vulturax. Despite the unit entry being a “Squadron” these just come in singles, but they are still a decent quick unit with some great weapons for suppressing enemy units. I’ve always loved the look of these, so excited to paint some up!

Karacnos Assault Tank

One of my favourite tanks returns for Liber Mechanicum, the Karacnos – which 2nd edition players will remember for raining down death on unfortunate units. The main gun is no a 5″ marker, so a little smaller than the massive apoc template it used to have, though it is still poisoned 2+, still drops toughness on units affected by it and causes pinning. the two lightning locks are very good with shred and breaching with a stock AP of 3 and S7 making this the perfect marine killer. It also has Suppressive making the Karacnos very good at sticking status aliments on units.

Krios Battle Tank

The Krios is back with it’s two weapon varients. The Lighting Cannon is now a slightly better Lightning Lock, which is ace, while the Irradiation Blaster is more like a short ranged Karanos mortar rather than the Hellstorm hell it used to be

Krios Venator

The Venator also returns, packing it’s Pulsar Fusil which is basically a damage 3 lascannon that gets 4 shots if it stands still. This is great on everything from tanks to Dreadnoughts and Saturnine Terminators.

Brass Scorpion

The first Lord of War in the book is the Brass Scorpion, which is an absolute power house with toughness 8, 15 wounds and a 2+ save with 5+ inv and Eternal Warrior reducing incoming damage by 1 it’s going to be tough to put down. As you’d imagine it’s loaded with weapons and with the Unstoppable rule can just walk out of combat

Kytan Daemon Engine

The second Lord of War in Liber Mechanicum is the Kytan, and like the Brass Scorpian this thing is amazing, and works out quite a bit cheaper in points too. It’s suitably powerful and has some ace weapons too. I’m torn on which of the Lords of War to pick up to add to my Xana force!

You might note here that there’s no Ordanatus – I suspect these are now legends.

Liber Mechanicum High Tech Arcana

One of the things added in Liber Mechanicum is the ability to have your units come from certain Arcana. Each of these grants different benefits to your units, often with an upgrade that can be taken for a points cost. In addition giving your High Command model a High Tech Arcana also unlocks some new Apex detachments that really let you lean into the type of units that Arcana would take, with some restrictions for flavour. I think these Apex Detachements will be popular, as they

For example, Cybernetica gains the ability to have your Archmagos, Dominus and Tech Priests make units of Automata able to score objectives if they join them, while Macrotek can be used to give nearby vehicles Invulnerable saves and increase their stats with a Prime advantage.

There’s 7 different Arcana in Liber Mechanicum and I feel that these are going to allow for lots of nice and varied lists leaning towards different playstyles. As technically you now build your army list after generating the mission this also means you can put together a force to suit the goal at hand.

Cybertheurgy

In Liber Mechanicum, you also get access to a suite of powers known as Cybertheurgy. These work a lot like Psychic powers but are based on an Intelligence test. Each power has a difficulty, which is subtracted from your Intelligence, and then there’s a chart of other modifiers that make each one easier or harder to cast – Some of these are quite tough to get off but have some decent abilities. Paired with this there’s a list of core Cybertheurgic Status that can be applied to units by using these such as increasing Movement and Initiative by 1, Strength and Toughness by 1, or increasing BS and WS by 1. This might explain why some units have taken hits to some stats, as you are able to modify them as you need to by using Cybertheurgy.

It’s not just buffs here, as there’s some really fun offensive ones too – one of my favourites is “Unseal the Portal” which if successful causes an enemy unit to have to do an emergency disembarkation from their transport!

We also get a couple of “Heterodox” rites, ones that used by those on the very fringes of what is within the laws of the Omnissiarh, and which will everentually lead to the Dark Mechanicum – these include things like Scrap Code which can be used to wipe the positive buffs put in place on enemy automata.

Like with the Arcana, there’s various extra rites available to certain sub-factions, and I can see this being something that is expanded further in a future Journal release.

Making good use of knowing which units to buff and when will be key to winning games as the Mechanicum.

Liber Mechanicum Appendices

Before we wrap up the review I just want to give the Appendices a massive shout out. One of the things that bugged me about 2nd edition was that weapon profiles were stuck in the middle of the book, and special rules and wargear were spread between the core rulebook and the liber. In 3rd edition that has changed with Liber Mechanicum having all of the Special Rules, wargear and weapon profiles for every single unit in the book in the very back. This makes it so much easier to look up these rules during battle without having to make book marks and flick back and forth while playing! Anything that makes gaming easier gets a massive thumbs up from me!

Summary

So what do I think about Liber Mechanicum? Well, I was a big fan of the Mechanicum in 2nd edition and it’s great to see a lot of that flavour brought forward to 3rd edition while giving some of the units that didn’t quite work a second pass. 3rd Edition is a bigger change than I first expected it to be, and as such a lot of units now have much different roles than they did previously, but this make such that there’s lots of different tools in the toolkit in order to achieve your goals.

My favourite thing is the number of different armies we are going to see now – you can easily lean in lots of different directions and I feel there’s going to be less cookie cutter lists this time round. If you want to lean into cybernetica and take all the robots you can, and stick characters in the units and they can score without having to take units just because you have to. Equally if you want to bring as many tanks as possible you can lean into Macrotek and have a very different mechanised force.

I’m going to have a lot of fun making lots of different lists to try and recreate different moments in the vast narrative background of the Horus Heresy, and ultimately that’s what the new Heresy edition is best at, making the battles feel like moments from the books we’ve enjoyed

Liber Mechanicum is up for pre order today and is released Saturday 26th July

Massive thanks to Games Workshop for sending us free review copies to check out on the site.