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View Full Version : On the value of Kurov's Aquila.



ChahDresh
07-14-2014, 09:03 PM
As a friend of mine and I have been doing some mathhammer in anticipation of NOVA, we’ve been discussing the merits of Kurov’s Aquila versus the AM’s other big force multiplier, Primaris Psykers.

For starters, it seems like the best way to maximize the Aquila is to put the Company Command Squad (CCS) in a Chimera. This helps to protect the investment made in the Aquila while maximizing its effect by giving the Aquila a larger footprint. (Incidentally, that larger footprint also benefits Orders and the Regimental Standard.) It also adds middling firepower. However, it also boosts the overall cost, to the equivalent of a level 2 Primaris and a level 1 Primaris.

What are the tradeoffs?

A line squad of Guardsmen at BS3 gets its To Hit rolls boosted by 1/12 by Preferred Enemy (PE). In contrast, Prescience boosts it by a full ¼. This would suggest that the Aquila needs to hit three times as many units to get the same benefit. However, this is not true, for two reasons.

First, PE also boosts To Wound rolls, while Prescience does not. This is an especially potent consideration for high-strength weapons like plasma guns and lascannon, since these weapons now wound on 2+ with reroll against most targets. (Someone once told me that 2+ with rerolls is pretty good…) That said, most of the time I have my line squads firing at vehicles, which wastes this benefit, so let’s set it aside for a moment.

Second, the Aquila doesn’t fail. It doesn’t need to be activated. The same cannot be said for psychic powers.

Under the new regime, a level 2 and a level 1 Primaris will *struggle* to successfully cast Prescience twice. Even with a ‘4’ roll for Warp Charge, you’re looking at four dice into your first cast and only three into the second, yielding success rates of 69% and 50%, respectively. That’s… not good. That also assumes that there’s no enemy interference—a valid assumption against, say, Tau. Against Eldar or daemons, not so much.

This means that a straight-up comparison of Prescience to PE is not meaningful. We have to factor in the cast probability of Prescience to make it a weighted average. Let’s be generous and assume a Prescience cast with four dice in its favor. This lowers your average hit rate down to about .67—a hair above 2/3s. 2/3 = 8/12. In other words, Prescience is merely twice as valuable as PE. In practical terms, PE is as valuable as two Prescience casters if you can affect four units that would, in isolation, be desirable Prescience targets… accounting for To Hit rolls only.

What if you’re affecting BS4 units, like Veterans? PE gives you 7/9 hits while Prescience gives you 8/9, for double the boost. But that’s before you factor in cast probability, which drops Prescience’s hit rate to 82%. That makes Prescience only half-again better than PE—if you hit two units with Prescience, the Aquila is equivalent if you hit three. And again, that’s To Hit rolls only.

Keep in mind, all of that mathy math ignores Deny the Witch and PE’s effects on the To Wound roll. Those factors become very important in a psyker-heavy metagame and if you’re able to boost high-strength weaponry. In fact, if you fall back on the gold standard (“what does this let me do against MEQs?”) and do a classic lasgun-versus-MEQ, you’ll discover that a lasgun with the Aquila kills one marine per 13.2 shots. A lasgun with Prescience (factoring in cast probability) kills… one marine per 13.3 shots. Basically the same, but the Aquila does it reliably and can affect more units. Advantage: Aquila.

Other considerations:

--In favor of the Aquila: if psychic powers perturb you with their randomness and the off-chance of making your guys’ brains explode, the Aquila is a great contrast: it’s always on… it’s not too hard to engineer a formation that lets you hit three, four, or even five different units with the Aquila when the CCS is in a Chimera… the Aquila is viable even if you take Pask. In fact, it’s almost better: if you give Pask Aquila coverage, you have PE against all targets, not the single Codex Pask’s warlord trait limits you to, and you can then make your CCS your warlord and get a warlord trait from elsewhere…

--Against the Aquila: your CCS is now even more of a target than before. Aggressive use of LOS-blocking cover and screening tanks can mitigate this, but it bears mentioning, especially if the enemy is toting barrage (though any barrage weapon is also a threat to snipe a Primaris)… in the same vein: all the formations that let you maximize Aquila coverage also maximize damage taken from Manticores and the like… Primaris Psykers provide additional functions beyond just Prescience. Although Prescience will typically suck up all their power dice, they boost leadership and help you Deny the Witch. An Aquila can’t do that… Prescience also works on blast weapons while PE does not… Prescience is vastly better against flyers and flying monstrous creatures…

Finally, although you might be tempted to list the Primaris’ ability to cast other powers as a point in their favor, the opportunity cost is that they’re not then casting Prescience. Casting Forewarning, for example, necessarily means not casting Prescience (as we’re Warp Charge-limited). This means that we’d be contrasting the merits of a 4++ against PE, and that’s not a happy comparison.

It would seem to me, in conclusion, that Primaris Psykers fit in more kinds of lists, but a list purpose-built to take advantage of the Aquila can derive more benefit from it than you could reap from Psykers.

Thoughts?

Magos Bellum
07-15-2014, 01:06 PM
Don't forget that the Aquila also allows the bearer to re-roll one failed leadership test per turn, it's not just a preferred enemy bubble.

ChahDresh
07-15-2014, 02:07 PM
Don't forget that the Aquila also allows the bearer to re-roll one failed leadership test per turn, it's not just a preferred enemy bubble.

I didn't forget, I just didn't mention it because I don't think it's that significant. Among other things, I run a Regimental Standard, which duplicates that effect. Also, in this scenario we've got the Aquila inside a Chimera, so no orders to the unit inside, and you're not taking morale/pinning checks until the Chimera is popped. Hm... you could *potentially* get a little bit of use out of the reroll one a crew shaken/stunned result, but that's a test you're taking rarely on a unit that's already Ld9.

On the whole, this part of the Aquila would have to be deemed a very occasional bonus, and not part of the primary effect.