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6 huge rules changes in the Warhammer 40k balance dataslate

The first Warhammer 40k balance dataslate for 10th edition makes changes to the core rules that will affect the dominant factions in the game.

Warhammer 40k balance dataslate fall 2023 - an Impeial Knight Magaera, a huge walking warmachine in red and brass armor, armed with a huge claw and lightning gun

Games Workshop has released a new Warhammer 40k balance dataslate, updating everything from the core Warhammer 40k rules to the way each Warhammer 40k faction is balanced. We’ve summarised the most impactful core rule changes from the dataslate, which was published on the Warhammer Community site on Thursday.

Reading the dataslate, many of the changes might seem small at first: a word tweaked here, an extra clause there. For the most part, they’re actually very impactful, addressing parts of the game that some tournament players have characterised as “clearly not balanced”, and which have certainly distorted the competitive meta in favor of factions like the Aeldari and Genestealer Cults.

As well as changes to the core rules, the dataslate contains targeted buffs and nerfs for many factions, alongside major points updates in the accompanying Munitorum Field Manual – we have another article about how the data-slate has affected Warhammer 40k faction balance.

Here are the six biggest rules changes in the fall 2023 Warhammer 40k balance dataslate:

Warhammer 40k balance dataslate fall 2023 - a yellow Aeldari wraithknight, a towering bipedal war construct made from psychic wraithbone

1. Devastating Wounds are less devastating

The balance dataslate changes how the Devastating Wounds weapon ability works. Critical To-Wound rolls now ignore all armor and invulnerable saves, but don’t cause any mortal wounds.

Against vehicles and monsters the rule is functionally identical, but it is a major nerf when targeting units with more than one model. When a normal wounding hit inflicts more than enough wounds on a model to kill it, the excess wounds are lost. But mortal wounds spill over.

Under the original wording of Devastating Wounds, anti-tank ordnance with the ability (such as the Wraithknight’s Heavy Wraithcannon) could wipe out an infantry unit with a single hit.

Warhammer 40k balance dataslate fall 2023 - a towering Chaos Knight, a corrupted walking warmachine

2. Towering units lose their 20/20 vision

Towering models like Imperial Knights now cannot see, or be seen, across ruins. Once they’re partially within a ruin they’re visible to units outside it, and likewise can target units through that ruin.

The original wording of Towering meant that these models were always visible to enemies, but they also had total freedom with their own lines of fire. Their controller could pick off any enemy units that posed a threat to their game plan at their liberty. In practise, this made Towering unit firepower oppressive.

This batrep by Play On Tabletop goes to show some of the force projection available to Towering units, under the original rules:

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This isn’t the only nerf to Towering units – see the changes to the Overwatch stratagem, below.

Warhammer 40k balance dataslate fall 2023 - gold-armored warriors of the Adeptus Custodes form a battleline

3. The menu of free Stratagems has been cut down.

Several unit abilities grant a free Stratagem each round, or allow a unit to use a Stratagem even if it has already been used this turn. The balance dataslate limits these abilities: if the ability allows you to pick any Stratagem, that can now only choose a Battle Tactic Stratagem.

Pre-nerf, this ability often equated to two free CP per turn, or simply an extra use of the army’s best Stratagem. The change means no more free Protocol of the Undying Legion for a Necron Overlord’s unit, no more free Counter-Offensive for Bladeguard led by a Space Marine Captain, and so on.

The Adeptus Custodes’ dreaded Unwavering Sentinels stratagem, which grants the unit the Fights First ability, has been changed so that it’s no longer a Battle Tactic Stratagem, and is thus caught by this ability.

Warhammer 40k balance dataslate fall 2023 - a Space Marine desolation squad, power-armored warriors armed with indirect-fire missile launchers

4. Overwatch is a lot more disciplined

The Overwatch Stratagem now has some tight stipulations on when you can use it. A unit can only fire Overwatch against an enemy unit that it can see; no more indirect-fire missile barrages. Also, Titanic Units can no longer fire Overwatch.

Tournament players identified the power of the Overwatch Stratagem early in 10th edition – potent indirect fire units like Desolation Marines or Nightspinners, or ruins-ignoring Towering units, could punish enemy units as soon as they moved, whether they were in line of sight or not. This change shuts down both issues.

Warhammer 40k balance dataslate fall 2023 -a Tyranid Neurotyrant, a terrifying creature with a huge cranium and dangling tentacles

5. Battleshock matters more

The Core Stratagem Insane Bravery, which allows a unit to auto-pass a failed Battleshock test, has been nerfed. It’s now limited to one use per battle, and you must declare you are using it before rolling for Battle-shock.

The 10th edition Warhammer 40k Battle-shock rules are nice and thematic, but Insane Bravery has contributed to them not feeling very impactful. The impact of Battle-shock is situational; a Battle-shocked unit can’t contest an objective, use Stratagems, or fall back from combat safely, but those don’t always matter. When it did matter, the original Insane Bravery Stratagem let a player buy their way out of the problem for 1CP.

Warhammer 40k balance dataslate fall 2023 - a display of index cards packs for four factions

6. Warhammer 40k has moved to a living rulebook model

All these changes will appear in the Warhammer 40k app and the free Index documents. The dataslate isn’t just errata for matched play, it updates the entire game. In effect, Warhammer 40k is moving to a ‘living rulebook’ model.

This isn’t innovative per se: miniature wargames like Warmachine and Infinity have made all their rules freely available in digital form for years. But it is welcome. Providing a digital ruleset means that everyone has access to the same version of the rules, without the need to lug around a stack of supplemental rulebooks and printouts.

Sadly, the Tyranids won’t enjoy these benefits, as their Index has disappeared from the Warhammer Community downloads page and the 40k app. We’re disappointed that Games Workshop isn’t keeping the Index rules free, as it makes onboarding a lot easier for new players – though the Tyranids Combat Patrol datasheet is still available.

All told, this is a major overhaul to Warhammer 40k. If you bought the Leviathan launch box set for 10th edition, but then lost steam painting miniatures as news of an imbalanced competitive environment filtered out from the tournament scene, perhaps these tweaks will be the reason to get stuck in again.