Ruleshammer 40k: The 10th Edition Commentary Has An Answer For That!

Welcome to Ruleshammer! This week I take a look at a few of the frequently asked questions that actually have answers in the massive 18-page Rules Commentary, plus a few bonus ones I’m throwing in!

There’s a lot to cover. But in everyone’s defence, I missed things the first time I read through the rules as well. I’m sure there’s stuff in there I still haven’t fully taken on. And while the Rules Commentary doesn’t answer every question we have, it does cover a lot. Here’s a compilation though of questions I’ve seen frequently over the last few weeks that are answered in the Commentary.

Devastating Wounds and Damage Modifiers

This one is fairly simple, and some might think the core rules are clear enough that they don’t even think to check the commentary… arguably because the commentary at least partially contradicts the core rules in this case. Let me explain, when you get a Critical Wound using a weapon with Devastating Wounds the attack becomes mortals equal to the damage characteristic of the weapon and the attack sequence ends:

Weapons with [DEVASTATING WOUNDS] in their profile are known as Devastating Wounds weapons. Each time an attack is made with such a weapon, a Critical Wound inflicts a number of mortal wounds on the target equal to the Damage characteristic of that weapon and the attack sequence ends.

As that attack has ended, it would never be allocated to a model and therefore not trigger the vast majority of damage reduction abilities, such as this one from Index Space Marines.

Duty Eternal: Each time an attack is allocated to this model, subtract 1 from the Damage characteristic of that attack.

However the commentary explains that despite this, in this situation players should still modify the damage characteristic before the conversion to mortal wounds.

Some rules modify the Damage characteristic of an attack that has the [DEVASTATING WOUNDS] ability.
■ When a rule modifies an attack’s Damage characteristic, if that attacks scores a Critical Wound, the Damage characteristic is modified before the damage is applied as mortal wounds.

Not ideal as a solution but it does reign in Devastating Wounds from almost all defensive abilities a unit might have.


Deathwatch Killteam
Photo Credit: Musterkrux

What toughness to use in a Mixed Unit

Throughout the editions of 40k there have been many different ways to address units with mixed toughness. 9th edition had several different ways that depended on the specific unit in question most of the time; for instance some units would use the majority toughness and some units like Tau would specify models to ignore for determining toughness instead. 10th has made mixed toughness units far more common again than they’ve ever been since 8th, and this time the answer is to take the highest toughness.

Unit’s Toughness Characteristic: If an Attached unit contains models with different Toughness characteristics, for the purpose of determining that unit’s Toughness characteristic, use the highest Toughness characteristic amongst that unit’s Bodyguard models. If a non-Attached unit contains models with different Toughness characteristics, for the purpose of determining that unit’s Toughness characteristic, use the highest Toughness characteristic amongst all of that unit’s models. In either case, When resolving attacks against such a unit, determine that unit’s Toughness characteristic when it is selected as a target.

One element that is significant though is that this determination happens when you target the weapons of a unit. So if the highest toughness in a unit was T5 and they were guarding a lowly T3 or T4 model, you don’t swap to using that lower value until that whole unit’s attacks have been resolved. This keeps the interaction fast rolling friendly but does let such units get a bit more bang for their buck from bodyguards even after they’ve all been destroyed.

When does an effect stop in an Attached Unit?

Generally this ruling clarifies that effects always continue to persist; this applies even if that unit is embarked or repositioned (the latter clarification being item 6 of the larger Repositioned Units section rather than with the main answer).

Persisting Effects: Some rules apply an effect that lasts until a certain duration has passed (e.g. until the start of your next turn). Such effects are known as persisting effects. If a persisting effect applies to a unit when it embarks within a Transport, make a note of that effect and its duration; if that unit disembarks for any reason, any persisting effects continue to apply to that unit for their full duration. If a persisting effect applies to an Attached unit and that unit ceases to be an Attached unit (because either all of its Bodyguard models or all of its Leader models are destroyed), any persisting effects continue to apply to the surviving unit for their full duration.


6. When a unit is removed from the battlefield to be repositioned, any rules affecting it for a specified duration or under specified circumstances continue to affect it while that duration/those circumstances apply. For example, a unit that was within range of an Aura ability when it was removed would no longer be affected by that Aura ability if it is set back up beyond that Aura ability’s range, whereas a unit that was Battle-shocked when it was removed would still be Battle-shocked until the start of your next Command phase.

One aspect of this I would like to further elaborate on is that Leader abilities are both persisting and not. Attached units stop counting as one unit after all the bodyguard or character models are dead AND the unit attacking them has resolved all it’s attacks. As such leader abilities continue to apply until that time as well!

While This Model is Leading a Unit: These rules only apply while the model with that rule is part of an Attached unit, and otherwise have no effect. While a model with such a rule is part of an Attached unit, it will also benefit from its own rule. If an Attached unit contains more than one model with such a rule, both models are considered to be leading that Attached unit, and so all such rules apply. Such rules cease to apply if that unit ceases to be an Attached unit (such as when the last Bodyguard model in that unit is destroyed) – if this is as the result of an enemy unit’s attacks, all ‘while this model is leading a unit…’ rules cease to apply after the attacking unit’s attacks have been resolved.

So they do “persist” for a moment, which keeps them fast rolling friendly, otherwise Leader abilities like this Tau one:

Enforcer Commander: While this model is leading a unit, each time a ranged attack targets that unit, worsen the Armour Penetration characteristic of that attack by 1.

would be a slow rolling nightmare, only every able to attack in batches large enough to kill the last Crisis model in the unit before they lost the AP modifier. Thankfully that’s not the case.

Are Critical Wounds Auto Successes?

Short and sweet one: Yes!

Critical Wound: A Critical Wound is scored when a player rolls an unmodified Wound roll of 6 for an attack. Critical Wounds are always successful Wound rolls, and can also trigger additional effects as described in certain rules (such effects are often said to be triggered ‘on a Critical Wound’, meaning when a Critical Wound is scored).

This also includes Critical Wounds caused by other abilities such as Anti X+.

Can I stack the same Core abilities cumulatively? 

Another short one but something everyone want to know! No.

The Core Rules describe dozens of abilities, including weapon abilities and deployment abilities. These are referred to as Core abilities, and most models, units, weapons or attacks either have one or more of them innately, or can gain them during the battle through other means such as Stratagems, Enhancements or attached Leaders. Regardless of the source, if a model, unit, weapon or attack has multiple instances of the same Core ability, those abilities are not cumulative, and only one instance of that ability can take effect at any one time. If that ability has a number after it (e.g. [SUSTAINED HITS 1], Scouts 6″), the controlling player must choose which instance of that ability to apply each time. Note that multiple instances of the [ANTI-] ability are only considered to be the same if the keyword listed after the word ‘Anti’ is the same (e.g. [ANTI-VEHICLE 4+] and [ANTIVEHICLE 3+] are considered to be the same ability, but [ANTI-VEHICLE 4+] and [ANTI-INFANTRY 2+] are not).

So you can’t get units up to Sustained Fire 3 by combining Sustained Fire 1 and Sustained Fire 2.

Black Templars vs Adeptus Custodes. Credit: SRM and Kriegsie

Is a unit without ranged weapons Eligible to Shoot?

Really I’m highlighting this entry because it’s relevant for a few secondaries such as Cleanse, Investigate Signals, and Deploy Teleport Homer. All of these require a unit Eligible to Shoot to achieve their aims, and there’s a large number of units that simply lack ranged weapons in 10th. This ruling clarifies they absolutely can still be chosen for this objective.

Eligible to Shoot (when not equipped with ranged weapons): Unless a unit Advanced or Fell Back this turn or is Locked in Combat, it is eligible to shoot, even if no models in that unit are equipped with ranged weapons. This means that such units can be selected for any rules that require you to select a unit that is eligible to shoot.

Realated to this:

I’ve been hearing about Eligible to Shoot having some odd issues, what’s that about?

Essentially the issue is that shooting, doesn’t Rules As Written make a unit “not eligible to shoot,” at least in my opinion and that of many others. This creates some likely unintended loopholes, the one you might have heard about most is Tau For The Greater Good chaining or spore mines performing actions but another issue this creates is being able to achieve those secondaries I just mentioned but shooting with the unit first and then choose it to do the objective after. Something that seems very much not the intend of those secondary objective seeing a they make the units you choose not eligible to shoot, why bother if they can shoot before doing it?

How does Overwatch work with shooting Eligibility?

Overwatch has more moments it can be used in 10th edition that it has before, some of them can cause questions about eligibility to come up. Overwatch in 10th edition is slightly different above and beyond it’s trigger timing in 10th.

    • WHEN: Your opponent’s Movement or Charge phase, just after an enemy unit is set up or when an enemy unit starts or ends a Normal, Advance, Fall Back or Charge move.
    • TARGET: One unit from your army that is within 24″ of that enemy unit and that would be eligible to shoot if it were your Shooting phase.
    • EFFECT: Your unit can shoot that enemy unit as if it were your Shooting phase.
    • RESTRICTIONS: Until the end of the phase, each time a model in your unit makes a ranged attack, an unmodified Hit roll of 6 is required to score a hit, irrespective of the attacking weapon’s Ballistic Skill or any modifiers. You can only use this Stratagem once per turn.

It’s now an “if it were your shooting phase” ability. This means that it interacts with abilities and other rules in a certain way based on this FAQ entry.

Some rules allow a model or unit to move, shoot, charge or fight outside of the normal turn sequence. For example, the Fire Overwatch Stratagem enables a unit to shoot in the opponent’s turn as if it were your Shooting phase. When using out-of-phase rules to perform an action as if it were one of your phases, you cannot use any other rules that are normally triggered in that phase.

What are the implications of that though? What if the unit you wanted to overwatch with was a Rhino with the Firing Deck ability. Firing Deck is a specifically “in the Shooting phase” ability

Some Transport models have ‘Firing Deck x’ listed in their abilities. Each time such a model is selected to shoot in the Shooting phase

So you couldn’t use Firing Deck for the Overwatch attacks. How about if they charge the Rhino and it wants to use Big Guns Never Tire. I think the first part of the ability is Shooting phase only and therefore doesn’t work.

Monster and Vehicle units are eligible to shoot in their controlling player’s Shooting phase even while they are within Engagement Range of one or more enemy units.

So no shooting with Monsters or Vehicles that have been charged during Overwatch, unless you shoot them before they make the move and end up in Engagement range. However the ability to shoot at Monsters and Vehicles within Engagement Range is not shooting phase locked.

You can select an enemy Monster or Vehicle unit within Engagement Range of one or more units from your army as a target of ranged weapons.

So if the Rhino was charged by a vehicle or monster, then another of your units would be able to benefit from BGNT to shoot at that enemy vehicle or monster..

Commentary Entries That Are A Bit Odd

Precision Attacks against units with Multiple Characters

I just want to call out that so far this is the only entry in the glossary that really has myself and other rules enthusiasts I know a bit stumped.

Attached Units with Multiple Characters (allocating attacks): Some units can have more than one Leader unit attached to them, and so can contain more than one Character model. Each time an attack with the [PRECISION] ability successfully wounds such a unit, the attacking model’s controlling player can choose to have that attack allocated to any visible Character model in that unit, rather than following the normal attack sequence. In such cases, allocate all [PRECISION] attacks that successfully wound before any saving throws are made.

So what’s wrong with it? Well this whole ruling is not written with the slow rolling nature of the game in mind, you don’t at any point in this game allocate attacks like this. You allocate attacks one at a time making saves, sometimes we might fast roll them in bataches. If you do as it says in that last line:

In such cases, allocate all [PRECISION] attacks that successfully wound before any saving throws are made.

does that mean that any precision attacks left over after the character is dead are lost, or do you allocate them again? We just don’t know.

Pre-FAQ Suggestion: Fast roll your attack as normal, and allocate your [PRECISION] wounds one at a time to a Character of your choice until you have allocated all of your [PRECISION] wounds or the enemy unit no longer contains any characters. Then continue the attack sequence as normal with any wounds not yet allocated. 

I’m not entirely sure if that works 100% of the time though, slow rolling should always be allowed though.

Have any questions or feedback? Got a rules question you want answered? Drop us a note in the comments below, ask a question in our Ruleshammer form, or head over to r/ruleshammer to discuss.