The Abominant is always accompanied by his Mindwyrm Familiar. It’s a simple rule, but complicated maths, and it’s time to bite that bullet…
Mindwymn Familar is a straight-forward rule. Every time the Abominant fights, he can reroll either a single hit or a single wound. This is great – it increases reliability, and leaves space to reroll a second dice using command rerolls; there’s no downside. However, it also introduces another decision: do I use my reroll on a failed hit, or save it for the wound? And further to that, it’s a full reroll, which is trickier to map out than rerolling 1s (because rerolling 1s boosts your final output by 117% , whereas the benefit of a full reroll varies depending on the number we need). With all that in mind, let’s see if we can work out how best to utilise the reroll, and how that affects the Abominant’s tabletop effectiveness.
WHEN SHOULD I REROLL?
In an attack sequence, the chance of forcing a save is the chance of hitting multiplied by the chance of wounding. For example, a WS3+ Abominant hitting a marine hits on 3s (2/3 chance) and wounds on 2s (5/6 chance) - we don’t need to worry about the save here, as the reroll won’t affect it directly. The base chance of forcing a save is 5/9, or 56% (for each individual attack).
If we apply a reroll to the hit roll, the chance of scoring a hit goes up to 8/9, and the chance of forcing a save becomes 74%. If we use the reroll on the wound roll instead, the wound roll goes up to 35/36, and the overall chance of forcing a save becomes 65%. In isolation (and against T5-or-worse targets), we’re better off rerolling the hit roll.
Full rerolls are interesting. Using WS as an example; as your WS improves, you’ll reroll less dice. Imagine rolling 36 perfectly distributed dice: at WS2+, 30 will hit, and only 6 will get rerolled; but at WS6+, only 6 of the 36 dice hit, and you reroll 30. So we get this:
I love this table – the obvious mirroring of hits and misses, the bell curve of the extra hits, the perfectly even progression of the overall increase. It makes me happy. And it shows us a couple of things.
Firstly, having a good WS still helps. WS2+ still scores more than WS3+, and so on down the line. You get to reroll less dice, but that’s because you already have hits in the bank.
Secondly, the worse your WS is, the more you benefit from full rerolls from a percentage point of view. Someone with WS6+ will almost double their original hits, because they have so many misses that they’re almost getting a whole second go at rolling. They still produce the lowest number of hits, but gain the greatest proportional increase.
Thirdly, the closer you are to WS4+, the more gain you see in absolute terms. WS4+ gains 9 hits (or 25% of the total dice rolled); WS3+ and 5+ gain 8 (for 22%); and WS2+ and 6+ only gain 5 (or 14%). WS4+ is the reroll sweet-spot, where the number of dice to reroll meets a reasonable chance of converting them into something useful (or to look at it another way, WS6+ gets to reroll lots, but has little chance of getting much out of it; WS2+ will convert most rerolls, but doesn’t get many to play with in the first place).
Back to our Abominant. As long as the hit and wound rolls are different (so, hitting on 3s, wounding on 2s, for example), it’s advantageous to reroll the more difficult roll – in this case, the hit roll. And if the rolls are the same (hitting something T6+, for example, where we hit and wound on 3s), it makes no difference and you can choose either. [Strictly, the rule is: reroll the one closest to 4+. But as it’s unlikely that the Abominant will ever get modified past 4+, it’s a bit moot in this case.]
That said, wound rolls don't exist in isolation - if we score no hits, there's no point in saving the reroll for the wound rolls, even if that's the more difficult roll. Imagine a situation where we're wounding something on 4s (like Transhuman). The bare maths suggests rerolling the wound roll for maximum efficiency. But if we only score one hit, what should we do? if we save the reroll for the wound roll, we'll have a 75% chance of landing that single damaging hit (and a 25% chance of missing altogether). But if we reroll one of the missed hits instead, we end up with a 17% chance of two wounds, 50% chance of one wound, and a 33% of no wounds - more chance of missing completely, but a chance of getting two wounding hits (and a higher average damage).
Helpfully for us, all this generally means that we’re better off rerolling the hit roll (which is always equal to or worse than the wound roll, modifiers aside). This is really useful, because we don’t need to worry about saving a reroll for the wound rolls, only to have them all come good and ‘waste’ the reroll. As soon as we miss a hit, reroll it. And if we don’t miss any? Great, then we can use it on the wound roll instead.
But how does that play out in tabletop effectiveness?
DAMAGE OUTCOMES
The maths here is slightly complicated. Unlike a standard reroll aura, which applies to everything, the Mindwyrm reroll applies to a single die We already know that we want to prioritise the hit roll, so we’ll only ever get to reroll a wound roll if we score three natural hits. But that also means that we can’t simplify the hit rolls to 2/3 x 2/3 x 8/9, because we might not be using the reroll here at all. Instead, we need to break down various possibilities, work out the probability of each, and then put it all back together again.
[Evening of happy spreadsheet-building happens here.]
Okay. This is going to make more sense in context. If we ignore the Mindwyrm Familiar reroll, and just go with the three attacks the Abominant comes with, run against various target types, we get this set of outcomes:
But once we take the Mindwyrm reroll into account, things look like this instead:
That is a huge increase. Look at those chances to score 3 damaging hits: a single reroll has increased the chances of maxing out by 150% (or to put it another way, you’re two-and-a-half times more likely to land three damaging hits with the reroll then without it). That’s an incredibly efficient reroll. Because we’re able to selectively apply it, primarily using it for hit rolls (where it’s most efficient), but also being able to save it to really hammer home the wound rolls when the hits go well, the reroll can become something of a ‘win more’ bonus – managed to roll three natural hits? Well done, you get to reroll a wound too.
Interestingly, the reroll effectively doubles our chances of scoring three hits (just hits, not the rest of the attack sequence). With WS3+, an Abominant will land all three hits 30% of the time (or 8/27). But he also has a 30% chance of landing two hits naturally, and converting the third into a hit with the reroll – the chances of two hits and a miss are 2/3 x 2/3 x 1/3 x 3 (a hit, a hit and a miss, in any one of three possible combinations), for a 12/27 chance of two hits; the reroll gives another 2/3 multiplier, bringing it down to an 8/27 chance of 3 hits. So overall, we now have a 16/27 or 59% chance of three hits – it’s just that half of them have already used up the reroll.
CONCLUSIONS
Sadly, all this still doesn’t turn the Abominant into a combat monster: his most likely results are 3 dead guardsmen, 2 dead marines, a wounded captain or a dented tank. Mindwyrm gives a degree of reliability to the Abominant’s attacks, but there are still only three of them in the first place. On a good day, the Abominant will smash anything, but those good days get further and further apart the more something is worth smashing.
As with a lot of Cult units, the Abominant feels like he's in a good place from a list-building point of view. He's generally underpowered as a combat piece, but has the potential to spike damage against almost everything, and could certainly have a role threatening support characters (depending on what you're facing). He's more convincing as a buffing piece, if you were already planning on leaning into aberrants (or just wanted to run with a thematic list) - even letting just five aberrants reroll their hits makes him more points efficient than simply adding more aberrant bodies, and that advantage only improves as we scale up.
Is he an automatic choice in every list? I don't think so. Can he carry his weight in the right situations? I think he can. And that's a good thing - turns out the Abominant isn't a mindless smash-button, but is a useful resource for getting the most out of one of our more unusual units.
That’s pretty much it for the Abominant. If you’ve not seen the other blogs yet, part one is a more specific breakdown of his combat output, and part two looks at his viability as a buffing piece. And if you’ve made it through all three, well done. I may not have convinced you to take the Abominant (I’m not sure I’ve convinced myself), but if you do, I hope he leads your revolution to glorious victory.