THE COVER LEDGER

From the first piece

Where Cover Lives made two arguments. The first: swapping cover from a +1 to the save into a −1 to the attacker’s Ballistic Skill is not cosmetic — it relocates cover to a different roll of the attack sequence and changes how the rule is used. The second: that relocation opens a problem. If the new cover is written as a Ballistic Skill modifier, it can stack with abilities that already impose −1 to hit, producing an effective −2 — and reviving exactly the modifier-stacking the current edition’s ±1 cap was built to prevent.

This piece is the next step. The previews give enough to stop describing the change and start measuring it — and the measurement challenges an assumption that is easy to carry out of the first piece: that −1 BS is simply a better deal for the defender than the +1 save it replaces. It is not. Not universally — and, as the closing sections show, not even for the units that look like its clearest winners.

Two currencies: −1 AP, or −1 to hit

Here is the cleanest way to see the change. A +1 to a save and a −1 to a weapon’s Armour Penetration are the same thing — both shift the save roll by exactly one pip. So 10th-edition cover was, in effect, −1 AP handed back to the defender on every weapon shooting the unit. The 11th-edition rule does not do that. It hands the attacker −1 to hit instead, and leaves the weapon’s AP untouched. The change is a swap of currencies: the defender stops being paid in Armour Penetration and starts being paid in hit-roll.

This article is the exchange rate — because −1 AP and −1 to hit are not worth the same, and how far apart they sit depends entirely on the unit and the weapon.

The swap also means the change is felt on two different rolls. The defender gains on the hit roll and loses on the save roll.

The gain — the hit roll — is a roughly flat benefit. A −1 to the attacker’s aim strips between a fifth and a third of incoming hits, depending on the shooter, and it always points the defender’s way.

The loss — the save roll — is the −1 AP going away, and its cost is not flat. Losing a pip of save is not a uniform tax: a model dropping from a 2+ to a 3+ fails twice as many saves, one-in-six becoming two-in-six; from a 3+ to a 4+ is ×1.5; from a 5+ to a 6+, only ×1.25. The better the save, the more the lost pip costs — which runs precisely opposite to the intuition that elite armour is the winner here. And the loss only bites where 10th cover was doing work in the first place: not against AP0 on a 2+ or 3+ model, where the old rule’s own exclusion denied cover anyway, and not where an attack’s AP had already pushed a model onto an invulnerable save, which cover never modified.

The table below shows that save-side loss in isolation — the failed-save multiplier, how many more saves a unit fails in 11th cover than in 10th. The 1.00 cells are the places the lost AP was worth nothing.

A numeric cell is the failed-save multiplier: ×2.00 means the unit fails twice as many saves as it did with 10th cover; ×1.33, a third more. A worded cell means the cover change cost nothing — for one of three reasons. excluded: against AP0 a 2+ or 3+ save was denied cover in 10th anyway, by the rule’s own exclusion, so there was nothing to lose. invuln: the AP has forced the model onto its invulnerable save, which cover never modified, so no cover was lost. bypassed: the AP defeats the armour save outright in both editions — cover’s +1 could not have rescued an already-doomed roll. All three are no change.

The net ledger

Multiply the hit-roll gain by the save-roll loss and you get the real durability change. The table below is the heart of this piece: five unit archetypes against five weapon classes, showing the wounds a unit suffers in cover under 11th as a multiple of what it suffered under 10th. The baseline attacker is a BS3+ shooter — the most common gun in the game.

Read: below 1.00, the unit suffers fewer wounds in cover under 11th than under 10th — more durable; 0.75 means a quarter fewer. Above 1.00, more wounds — more fragile; 1.50 means half again as many. 1.00 is no change.

The shape of that table is the finding. Read it by archetype.

Light infantry (5+ save). The clean winner — and the quietest one. A 5+ model never comes out behind: break-even against AP0, better against everything else. This is the “good saves lose more” rule running in reverse. A 5+ save losing a pip is the cheapest version of the loss, and once any real AP is involved the cover save was barely holding anyway. Cheap infantry get a small, genuine durability bump and no real downside.

MEQ (3+ save, no invulnerable). Mostly fine, with one sore spot. The standard Marine improves against AP0 fire and against AP3-and-up, sits roughly break-even against AP2, and is worse — about 13% more wounds suffered — against AP1. AP1 is a very common weapon class, so that is not a trivial exception.

Heavy vehicles and 2+ infantry, no invulnerable. The biggest loser, and it is not close. A 2+ save with no invulnerable to fall back on was the ideal beneficiary of 10th cover — that point of returned AP could make an AP1 weapon glance off a 2+ almost entirely. Strip it and an AP1 gun is fifty percent more effective into a 2+ model than it used to be; an AP2 gun, 13% more. The −1 to hit does not come close to covering the gap.

And this is not only a tank’s problem. The ledger reads nothing but the save profile, so any infantry model with a 2+ save and no invulnerable — the Grey Knights Strike Marine, on its previewed 2+ — sits on exactly this line, identical in the tables to the heavy vehicle. That is the edge case worth flagging: elite armour with no invulnerable backstop is the single most exposed profile under the new cover, whether it is bolted to a tank or worn by a Marine. A 2+ save is the best thing to own under 10th cover and the worst under 11th, and a Strike Marine on a 2+ owns the bad end of that trade — an AP1 weapon into it is twice the threat it was, with nothing behind the armour to catch what gets through.

Knight-class walkers (3+ save, 5++ invulnerable). A hybrid, and a modest winner. At low AP a Knight behaves like the MEQ — same 3+ armour, so the same shallow dip and the same single sore spot at AP1 (×1.13, 13% more wounds suffered). At high AP it behaves like the Terminator: AP3 and above push it onto the 5++ invulnerable that cover never touched, so the −1 to hit there is pure gain (×0.75, a quarter fewer wounds). AP2 lands exactly on the break-even line. A Knight in cover therefore comes out ahead at both ends of the scale and only just behind in one mid-band — a gentler version of the Terminator’s curve, because losing a pip from a 3+ costs ×1.5 in failed saves where losing it from a 2+ costs ×2.0. (A Knight that has improved its invulnerable save — to a 4++, say — flattens the AP1–AP2 dip further still.)

Terminators (2+ save with a 4++ invulnerable). The most distinctive line on the chart: it humps upward through the middle. A Terminator in cover gets more durable at both ends of the AP scale and less durable in the AP1–AP2 band. Against AP0 it improves — the 10th exclusion meant cover did nothing for its 2+ anyway, so the −1 to hit is pure gain. Against AP3 and AP4 it improves again — the AP has pushed it onto its 4++, which cover never touched, so once more the −1 to hit is pure gain. But against AP1 and AP2, the band where the armour save is still in play and cover was actively returning AP, the Terminator is worse off — by 50% and 13% respectively. (If the line looks like a face, it is not smiling — the hump is the bad part, rising into worse-durability territory.)

There is a narrative logic to that hump worth naming. Under the new cover the Terminator behaves the way a Terminator is supposed to. Small-arms fire bounces — the 2+ armour holds, and the −1 only makes the chaff worse at landing hits in the first place. Dedicated anti-tank fire is inefficient into it — its great Strength and AP spent punching a model that was always going onto its invulnerable anyway, and now landing fewer of those expensive shots. And the weapons that come out ahead are the ones in between: the AP1–AP2 guns built to crack elite infantry. The cover change sorts the Terminator’s threat table into something coherent — wrong tool, wrong tool, right tool. For Terminators it is arguably a more consistent meta than 10th’s, even where it is a nerf.

Working one case in full

Take the case that makes the trade concrete: a damage-D3, AP1 weapon firing into a Terminator unit in cover, against a BS3+ shooter.

Under 10th edition, cover’s returned AP lifts the Terminator’s save against that AP1 weapon back up to a 2+ — it fails one save in six — and the shooter, unmodified, hits on 3s. Damage gets through on four attack-results in thirty-six. Under 11th edition there is no returned AP, so the Terminator is on a 3+ against the AP1 and fails two in six, and the shooter, at −1, now hits on 4s. Damage gets through on six in thirty-six. The D3 damage profile never changed. The hit roll and the save roll did, and they did not cancel: that weapon is half-again as effective into Terminators in cover as it used to be. A gun that was a poor pick into Terminators is now a fine one.

Now the contrast — the same Terminators, shot by massed AP0 fire. Under 10th, the exclusion gave a 2+ model no cover against AP0 at all, so the Terminators sat on a flat 2+ and the shooter hit on 3s. Under 11th the save is still a flat 2+ — nothing was lost, because nothing was being given — and the shooter now hits on 4s. The Terminators take a quarter fewer wounds. Same unit, same cover, two weapons, opposite verdicts. The 11th rule does not make hard targets uniformly harder or softer. It re-sorts which weapons threaten them.

Edge case: one weapon, both sides of the ledger

The case above used an abstract AP1 weapon. A real one can show the ledger’s whole range inside a single datasheet. Take the Riptide’s ion accelerator, which fires in two modes — a standard profile of Strength 9, AP2, 3 damage, and an overcharged profile of Strength 10, AP3, 4 damage. Treat it here as an ordinary shooter, one that takes the cover penalty the way most models do; whether the actual Riptide does is a wording question the next section returns to. Point both modes at a Terminator (Toughness 5, 2+ save, 4++ invulnerable) in cover.

Start with the wound roll, because the modes differ there and it is worth being clear about what that does and does not change. Strength 10 is exactly double Toughness 5, so the overcharged shot wounds on 2s; Strength 9 is above Toughness 5 but short of double, so the standard shot wounds on 3s. That gap is real, and it is most of why the overcharged mode does so much more raw damage. But the wound roll is identical under both cover rules — it cannot move the 11th-versus-10th ratio. The ratio is settled entirely on the hit roll and the save roll.

And on those two rolls, the modes sit in different bands. Standard mode is AP2: against a Terminator the armour save is still the operative save, and 10th cover was actively lifting it — to a 3+. Overcharged mode is AP3: enough to push the Terminator onto its 4++ invulnerable, which cover never modified at all. Per shot, into a Terminator in cover:

The dmg/shot figures are expected damage from one shot — the average wounds the Terminator takes, counting hit, wound and save. The final column is the 11th figure divided by the 10th: above 1.00 the weapon got better into a Terminator in cover, below 1.00 it got worse.

So the same weapon, the same trigger-pull, splits cleanly across the ledger. The overcharged mode — the high-Strength, high-AP, “anti-elite” mode — becomes less efficient against a Terminator in cover under the new rule, by a quarter to a third: AP3 was always going to land on the invulnerable save, so 10th cover was doing nothing there, and the −1 to hit is pure gain to the defender. The standard mode — lower Strength, AP2 — becomes break-even to slightly better for the attacker, because AP2 is exactly the band where 10th cover was doing its work and the new rule takes it away.

One thing the table does not show cuts against the overcharge. Those figures are raw expected damage — they count every point a shot deals, including points that spill past the target’s wounds and vanish, because 10th edition allocates damage with no spillover. A standard Terminator has 3 wounds; the overcharged profile deals 4. Against a 3-wound Terminator the fourth point is wasted on every failed save, so the overcharge’s effective damage is 3 — the same as the standard profile’s. Its raw-damage lead there is overkill. The overcharge earns its profile against a 4-wound model — Deathshroud Terminators, say — where the standard profile’s 3 leaves the model alive on its last wound and the overcharged 4 removes it cleanly.

So the tactical reading is not “stop overcharging” — but it is more conditional than the raw table suggests. Against a 4-wound target the overcharged profile is plainly the pick; against the 3-wound Terminator, with the wasted fourth point and the cover re-pricing both counted, the two profiles are closer than they look. The subtler point is the one the ledger keeps making: the cover change is not a flat modifier on a weapon’s effectiveness. It re-prices a weapon mode by mode, and it does so against instinct — the harder-hitting, higher-AP mode is the one it blunts most against elite armour in terrain.

The exception: a shooter the cover penalty cannot touch

Every case so far assumes the cover penalty actually lands on the shooter. Some models are built so it never does — and the cleanest example is the Hekaton Land Fortress.

The Hekaton ignores both modifiers to its Ballistic Skill and modifiers to its hit rolls. That double coverage is the important part. The first article left one question open: whether 11th cover is written as a Ballistic Skill modifier or as a hit-roll modifier. For most models the answer matters. For the Hekaton it does not — whichever way the rule is drafted, the Hekaton ignores it. The cover penalty simply never reaches it.

For a shooter the penalty cannot touch, the ledger collapses to one side. The defender in cover still loses the +1 save; the shooter still hits at its full Ballistic Skill. There is no hit-roll gain at all — so the durability ratio is purely the save-side loss. Run the Hekaton’s weapons against a Terminator in cover:

Durability ratio (11th ÷ 10th) for a Terminator in cover. Because the Hekaton ignores the cover penalty, the ratio is purely the save-side loss — never below 1.00. ×2.00 means the Terminator takes twice the wounds it took in 10th cover.

So the Hekaton universally benefits from the cover change. Not one of its guns gets worse against a target in cover. Its AP1 hull guns — the sustained-fire weapons it carries in bulk — become twice as effective into a Terminator in cover as they were in 10th, because an AP1 weapon into a 2+ save is exactly the ×2.00 cell of the failed-save table. The conversion beamer, AP2, is half again as effective; only the rail gun, at AP4, is a wash, because AP4 had already pushed the Terminator onto its invulnerable, where cover never reached. A model that ignores the penalty does not merely dodge a nerf — it collects the defender’s lost save for free.

A word on what this does not generalise to. It is tempting to say every “ignore modifiers” rule hard-counters the new cover; it does not. The rules vary. The Riptide, for one, ignores modifiers to its hit rolls but not to its Ballistic Skill — so whether it dodges the new cover depends entirely on the wording question above, and its reliable route to ignoring cover is markerlight support, which works identically in 10th and 11th and so does not bear on this comparison at all. An ability that ignores only hit-roll modifiers, or only Ballistic Skill modifiers, escapes the new cover only if the rule happens to be written its way. The Hekaton is the clean case precisely because it ignores both and so cannot be wrong-footed by the drafting — and it is close to unique in that. Treat it as a specific warning, not a general one.

The −2 special case

Now fold in the first piece’s open problem. Some units already carry an ability that imposes −1 to hit on the models shooting them. In 10th edition such a unit, in cover, had two things at once: the −1 to hit from its ability, and cover’s −1 AP. In 11th edition — if the new cover is written as a Ballistic Skill modifier, the unresolved question from Where Cover Lives — its cover no longer returns AP; it adds a second −1 to hit, stacking with the ability into an effective −2.

That makes these units the cleanest possible test of the exchange rate, because the trade is stripped bare. They give up cover’s −1 AP and receive, in return, a second −1 to hit. Nothing else moves. The question is simply: does the second −1 to hit pay for the lost AP?

Take the Terminator again — the 2+/4++ unit, the case the first piece raised through Grey Knights. Three versions of its durability ledger, against a BS3+ shooter:

Same reading key: below 1.00 more durable, above 1.00 more fragile, against the 10th-edition baseline.

Read the middle row first — the −2 case. The second −1 to hit helps: it pulls the AP1 sore spot down from ×1.50 to ×1.33 and turns the AP2 column into a wash. But it does not clear the bar. Against an AP1 weapon, a Terminator with the strongest hit-side benefit the 11th rule can produce — a full −2 — is still a third more fragile than it was in 10th. The reason is the exchange rate. Against a 2+ save, the −1 AP that vanished was suppressing a doubling of failed saves, ×2.00. To pay that back on the hit roll alone you would need to halve incoming hits — a hit factor of 0.50 — and a −2 against a BS3+ shooter only reaches 0.667. The AP was worth more than the two −1s that replaced it.

The bottom row is the other branch of the first piece’s open question, and it is worse. If the new cover is written as a hit-roll modifier rather than a Ballistic Skill modifier, the unit’s ability and cover share the ±1 cap — and since the unit was already at −1, cover adds nothing. It gets no hit-side benefit at all and simply loses the returned AP: against an AP1 weapon, a flat doubling of wounds suffered.

So for the units the first piece worried about, the cover rule’s wording does not merely settle a stacking edge case. It decides whether they land on a −2 — helped, but still down against low AP — on a standard −1, or on a wasted cover that leaves them purely worse. None of the three branches makes them durability winners against AP1. The −2, the best of them, only makes the loss smaller.

The shooter matters too

The net tables above hold one thing fixed: the attacker is a BS3+ gun. But the hit-roll gain is not constant — it shrinks the better the shooter is, because a −1 is a smaller relative cut to a unit already hitting on 2s than to one hitting on 4s. Against an elite BS2+ army the defender gains less from cover; against a BS4+ chaff army, more. The standard Terminator’s ledger across attacker skill:

That tilts the ledger further. The Terminator’s AP1 sore spot is a ×1.33 against a BS4+ shooter, a ×1.50 against BS3+, and a ×1.60 against a BS2+ army. The −2 unit does not escape it either: its AP1 column only reaches break-even against a BS4+ shooter, and against BS2+ and BS3+ guns it stays underwater. And against a BS5+ shooter the second −1 falls off the natural-6 floor — an unmodified 6 always hits — and does nothing, leaving the −2 unit no better than the capped case. Across every realistic shooter, an AP1 weapon into elite armour in cover is a better weapon in 11th than it was in 10th.

What the ledger says

The headline from Where Cover Lives — that the new cover is “a broad nerf to shooting and a broad buff to durability” — is too broad. The buff to durability is real, but it is targeted, and not at the targets the first piece implied.

The change rewards the units 10th cover under-served: bad saves the returned AP was barely helping, and elite units against the weapons that already ignored their cover — AP0, where the 10th exclusion bit, and high AP, where the invulnerable save had already taken over. It punishes good armour saves against the broad midfield of AP1 and AP2 weapons, where 10th cover was quietly doing its best work. A 2+ save was the best thing you could own under the old rule. It is the most exposed thing you can own under the new one — and, as the −2 case shows, not even a stacked hit penalty buys that exposure back.

A second pattern sits underneath the first. Cover’s whole defensive contribution under the 11th rule is the −1 to hit — so a shooter that does not take that −1 collects the defender’s lost save for nothing. But which abilities actually escape the penalty depends on its final wording, and on whether a given “ignore modifiers” rule is written for hit rolls, for Ballistic Skill, or for both. The Hekaton Land Fortress, which ignores both, is the clean case; most such rules cover only one channel and dodge the new cover only if it happens to be drafted their way. To-hit buffs and ignore-cover effects are the broader levers that decide how much the new cover is worth on a given table — but the specific “ignore modifiers” interaction is one to check rule by rule, not assume.

For list-building, the cover change is not a reason to trust your Terminators or your heavy tanks more. It is a reason to respect the AP1–AP2 weapons in the room — the autocannon-class and plasma-class guns — because those are the weapons the change quietly upgrades, and elite armour sitting in terrain is exactly what they will be pointed at.

Caveats, kept short

This is a controlled comparison: same unit, same datasheet, only the cover rule changed. 11th edition will re-stat units, and a re-stat can move any single number here — but what it cannot easily move is the shape, the hump in the AP1–AP2 band for good armour, because that shape comes from the structure of the two rules rather than from any one profile. The comparison uses clean template maths — no re-rolls, no Feel No Pain, no other hit- or wound-roll modifiers — which shift the exact cells without changing the direction. And it assumes the previewed wording, cover as a −1 to the attacker’s aim; whether that −1 is written as a hit-roll modifier or a Ballistic Skill modifier is the one place the wording still matters, and the −2 case and the Hekaton example above work through what turns on it.

The first piece asked where cover lives. This one asks what it costs. The answer is that it costs different units very different amounts — and that a rule read as a gift to hard targets is, against a large slice of the weapons they will actually face, the opposite.

— The Editor