Hammer of Math: Astra Militarum Regimental Doctrine Deep Dive

This week’s Hammer of Math takes a look at the new Regimental Doctrine system in the new Codex: Astra Militarum.

The Imperium of Man is a million worlds, and all of them are obligated to provide some sort of support in the defense of humanity. Some of those words provide food, others provide arms or precious resources, and countless others provide what is generally considered the most expendable resource of all in the 40k Universe; bodies. The diversity of these worlds is reflected in the diversity of the Astra Militarum, with each world providing varying numbers of regiments depending on the population, proximity, and needs of the Emperor.

Much like Space Marine Chapters, Hive Fleets, and numerous other armies, the newest Codex: Astra Militarum contains options for custom regiments through the Regimental Doctrine system. What is different from previous books is that there are no “standard” regiments. Instead every player has the option of taking the default doctrine of Born Soldiers, or selecting two options from 15 Regimental Doctrines (the exception being Trophy Hunters, which GW apparently thinks is so good that you cannot select a second doctrine after picking that one). This means that we can look at the impact of the default doctrine, and then examine the other options in the context of an opportunity cost.

Steel Legion as Certusian Charnel Guard. Credit: Skails

Regimental Doctrines

The sections below discuss the mathematical impact of the various Regimental Doctrines, and compare them to the opportunity cost of the Born Soldiers ability. Note that occasionally a doctrine will produce a modifier on the roll; the impact of the modifier depends on the original target value being modified. For example going from a 6+ to a 5+ improves the probability by 100% (from 1-in-6 to 2-in-6), while going from 3+ to 2+ is only a 25% improvement.

Born Soldiers

Born Soldiers has two effects. The first is that units with the OFFICER keyword have a 6″ aura which allows friendly PLATOON units to use the OFFICER’s Leadership characteristic instead of their own. The second is that ranged attacks with an unmodified hit roll of 6 automatically wound the target and are considered to have an unmodified wound roll of 6 for purposes of other rules or effects. In probability terms this means that 1 in 6 times the attack sequence will skip the wound roll. This can have a significant impact on the probability of wounding a target, as we saw with the Leagues of Votann. The chart below shows the change in wound probability for the entire range of hit and wound targets.

In general Astra Militarum have a BS of 3+ or 4+. As one would expect the impact of the default ability depends on the type of target, but for a typical engagement of a BS 4+ guardsman firing a S3 lasgun against other infantry targets the improvement is a 33% or 67% increase in wounding probability. Even against targets that are being wounded on a 3+ the increase in wounding probability for a BS 4+ unit is equivalent to being able to re-roll wound or hit rolls of 1.

The Leadership bonus seems pretty paltry. Most core units have a Leadership characteristic of 7 or 8 on the Sergeant, while nearby Commissars and Platoon Commanders have a Leadership characteristic of 8. There’s a better benefit with the unique characters, which generally have a Leadership characteristic of 9, or Lord Solar Leontus who has a Leadership characteristic of 10.

Unfortunately there’s not enough room for everyone. Credit: SRM

Mechanised Infantry

Units with the Mechanised Infantry doctrine units can disembark from TRANSPORT models that have made a Normal Move, which normally can only happen when the vehicle has a particular rule like the Assault Vehicle rule of the Space Marine Impulsor. Whether or not the added mobility is worth the opportunity cost of reduced lethal output is a challenging consideration, especially given how Regimental Tactics (which normally allows an order to a PLATOON to spread to nearby PLATOON units) does not work when an OFFICER issues an Order after disembarking.

Parade Drill

This doctrine allows you to change the Type of lasguns and hot-shot lasguns to Heavy 2 if the unit Remained Stationary in the Movement phase. Doubling the driving roll of attacks is generally helpful (effectively a +100% increase relative to a single shot weapon), but the effect is superseded by the Regimental Order First Rank, Fire! Second Rank, Fire! which changes to type to Heavy 3 and does not require the unit to have Remained Stationary. It also provides no benefit for any weapon outside of the two lasgun options or when the target is within 12″ of the attacking unit.

Armoured Superiority

Armoured Superiority provides a bonus to various VEHICLE models in terms of controlling objective markers. SENTINEL models count as 3 models (+200% benefit), TITANIC models count as 10 (+900% bonus), and all other VEHICLE models count as 5 (+400%). If you’re dedicated to tanks then you’ll want to combine this with Shock and Awe! Order to also give them Objective Secured.

Scout Sentinel. Rockfish
Scout Sentinel. Rockfish

Blitz Division

This bonus is entirely about changing deployment. Units halve their Power Rating when determining how many Command points have to be spent to put them in Strategic Reserves, while in the second battle round any VEHICLE that isn’t a SENTINEL treats it as if it was the third round for purposes of determining where those reserved units can deploy. Given how valuable Command points are in Nephilim matched play games combined with the limitation of setting up Strategic Reserves with the 9″ bubble it seems unlikely that this ability is worth the opportunity cost of losing Born Soldiers.

Expert Bombardiers

Players who like ARTILLERY might want to consider this doctrine, which allows friendly VOX-CASTER and SENTINEL units to serve as spotters. Under this doctrine, ARTILLERY models which make ranged attacks against units within 12″ of those units get a +1 modifier to the hit roll. For a BS of 4+ this translates to a 33% improvement which makes this bonus better than Born Soldiers for attacks with a wound roll of 2+ or 3+, and equal for attacks with a wound roll of 4+. This doctrine would favor a list that’s heavy with Basilisks and Manticores, which have indirect attacks with a high Strength characteristic.

Heirloom Weapons

This doctrine adds 4″ to the Range characteristic of every non-Relic weapon in the regiment. The benefit is naturally proportional to the Range of the weapon, benefiting short-range options like the meltagun and flamer more than something like an Earthshaker cannon. 12″ range weapons like a meltagun or Rapid Fire range of a lasgun will get a 33% improvement, while weapons with a 24″ range see a 17% increase.

Recon Operators

Recon Operators allows INFANTRY, CAVALRY, and SENTINEL units to make a Normal Move before the first turn begins. The maximum movement is 6″ and as per usual models are limited from ending the move within 9″ of the enemy deployment zone or enemy models. A 6″ move is enough to get within range of an objective marker in No Man’s Land for every mission but Data Scry-Salvage and Abandoned Sanctuaries. Note that Scout Sentinels gain nothing from this doctrine since they have Daring Recon.

Trophy Hunters

For whatever reason this is the only doctrine that GW considers good enough to justify not permitting you to take a second doctrine, and frankly it’s difficult to understand why. Trophy Hunters gives you a +1 the Strength characteristic of attacks against MONSTER or VEHICLE units. Note that it specifically says Strength, as opposed to some kind of bonus to wound rolls which would be guaranteed to apply. Assuming the bonus causes the wound roll to pass a threshold and increase the probability, the benefit will likely range from +50% to +33% assuming the original wound roll target was a 5+ or 4+. For a BS of 4+ Born Soldiers is either just as good or better and is guaranteed to apply regardless of weapon characteristics or target. There seems to be no reason whatsoever to take this doctrine.

Cadian Commander. Credit: Jack Hunter

Grim Demeanor

This doctrine is pretty simple; you ignore all modifiers to Combat Attrition tests. This has no applicability for VEHICLE units and is highly situational for Astra Militarum INFANTRY since most units get slaughtered before they have a chance to run away. The most common modifier is being below Half-strength, so in the event that you take a Combat Attrition test with less than half a unit left Grim Demeanor will reduce the probability of losing each model by half.

Brutal Strength

This doctrine basically screams CATACHAN. Under Brutal Strength INFANTRY models do not suffer a penalty from moving and firing Heavy weapons, and INFANTRY models that charge, were charged, or made a Heroic Intervention get to add 1 to the Strength characteristic of melee attacks until that fight is resolved. Going from a 5+ to hit to a 4+ to hit is a +50% bonus, which is pretty significant but also limited since INFANTRY units outside of Heavy Weapons Squads are limited to a single heavy weapon. As discussed with Grim Demeanor the bonus to Strength is generally worse than the effect provided by Born Soldiers.

Veteran Guerrillas

From a fluff perspective this doctrine complements Brutal Strength as the CATACHAN build. INFANTRY and SENTINEL units under Veteran Guerrillas ignore the benefits of cover when targeting units that are within 18″. When examining the effect of modifiers to armour saves, it’s best to subtract the probability of making a save from 100% so that you can take the perspective of harming the target. For example if a model has a 5+ armour save then the probability of wounding them is 100% – 33% or 67%. In the case of Dense Cover the bonus from going from BS 5+ to 4+ is +50%, which means the bonus is only better than Born Soldiers in situations where the wound roll is a 2+ or 3+. The same is generally true for Light Cover, where the target either has to have a very high Save characteristic or need a wound roll of 2+ or 3+ to be better than the default doctrine.

Credit: BuffaloChicken

Elite Sharpshooters

Elite Sharpshooters provides you with the ability to re-roll one hit roll every time a unit makes an attack. Regardless of the roll, re-rolls provide a fixed alteration to the probability in the form of a 16.7% (1/6) increase for every number that is re-rolled. So re-rolling 1s gives a 16.7% boost, re-rolling 1s and 2s provides a 33% improvement, etc. The issue is that a single re-roll is pretty insignificant given the volume of fire that most Astra Militarum units produce. Something like a Rogal Dorn Battle Tank will make an average of 20 attacks even when exclusively choosing weapons with the lowest number of shots. VEHICLE units also have access to re-rolls through orders like Gunners, Kill on Sight!

Death Korps of Krieg. Rockfish
Death Korps of Krieg. Rockfish

Cult of Sacrifice

This doctrine provides a +1 bonus to hit rolls so long as the unit is below Starting Strength. This means that the doctrine is useless for single model units like any VEHICLE unit which isn’t a SENTINEL. As we’ve established with other doctrines, the bonus to hit for a BS of 4+ is worse than the bonus from Born Soldiers unless the target is being wounded on a 2+ or 3+.

Industrial Efficiency

Attacks with an Armour Penetration characteristic of -1 are treated as having a characteristic of 0 against models with this doctrine. -1 is a characteristic commonly seen on anti-INFANTRY weapons like heavy flamers, heavy bolters, autocannons, etc. In the case of your standard Guardsman going from a 6+ to a 5+ is a +100% improvement in the probability of survival.

Swift as the Wind

This doctrine seems to complement Expert Bombardiers pretty nicely if you like the idea of fast scouts racing ahead to bring down steel rain on the heads of your enemies. This doctrine boosts the Move characteristic and charge range of models, adding 1″ to the Move characteristic to INFANTRY and ARTILLERY models while giving 2″ to everything else. Units with this doctrine also add 1 to all charge rolls, which allows me to include my favorite image on the website below. 14″ Hellhounds and Scout Sentinels seems like a lot of fun, as does Bullgryns with a Movement characteristic of 7″ and a bonus inch on the charge.

At least they get to start at 9″

Wrapping Up

Born Soldiers is an extremely effective and flexible doctrine, and several of the other options suffer from being more subjective and limited when compared to the default option. Several of the options are oddly bad due to the availability of better orders (Parade Drill) or an inexplicably restrictive option which is worse than the default outside of a few niche cases (Trophy Hunters). Other options like Elite Sharpshooters or Cult of Sacrifice seem interesting on the surface, but lose their appeal under a deep dive. The most appealing alternatives seem to be Mechanised InfantryArmoured Superiority, and Swift as the Wind as these doctrines provide a benefit outside of raw lethality.

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