Unit of the Week: Doomsday Ark

[Daimyo-Phaeron Lenoch]

 

Welcome to the Unit of the Week Series!

 

Each week a different unit will be highlighted for discussion until we have amalgamated a full list of our available options and their relevant tactics as 9th edition evolves. This will include not only matched play, but free play considerations as well as Crusade, as these methods of play are just as relevant and exciting.

 

Please keep in mind this isn't to lament the status of featured units or compare them to others but to try and find their potential for all types of gameplay.

 

This week’s unit is:

 

The Doomsday Ark

 

As a loose guide, here are some thought-provoking questions to consider and cogitate as we discuss this week's unit(s):

• Do you take the one, or is it best in multiples?
• Which dynastic codes work best for the Doomsday Ark?
• Do you deploy it aggressively, or defensively?
• How do you use this unit in your listbuilding process?
• What are overall strengths and weakness of this unit?
• Which stratagems synergize well with this unit?
• Which specific Crusade benefits best suit this unit?

Edited December 29, 2020 by Daimyo-Phaeron Lenoch

[Mr4Minutes]

They needed to have some of the random profile removed.

 

They can roll hot a destroy a repulsor in one shooting phase, but more often then not, for me, they barely strip 2 wounds off an exocrine. I’ve actually gone and removed both Doomsday Arks and Doomstalkers from my list because the variance always lets me down.

 

On a positive, with quantum shielding and the strat to increase the invuln to 4++, they are fairly durable. Which is good, because their punishing weapon profile degradation if they move kind of forces you to deploy them in the open and hope they survive.

 

I’m sure others have had better success and more positive outcomes with Doomsday Arks. But for me, when I’ve taken these as my dedicated anti armor option, they’ve almost always let me down.

[VoceNoctum]

I think they look neat, so got one, but I don't think they can really be discussed solo. The Canoptek Doomstalker overlaps a lot. 2 Arks (20 power) vs 3 Stalkers (21power), the Cannon is basically the same except for range, which seems odd to me.

Quantum Shield is 5+ with no wound on 1-3 vs 4+ invul.

Ark is a little faster, but doesn't explode as easy. Vehicle vs Monster, Canoptek vs not.

Arks are 10 flayer blasts each (so 20 for 2) vs 2 each (for 6 for the 3) and Ark's get better BS.

 

Anyway, I'll probably take an Ark and a Stalker or 2, using the Ark to sit in the backfield to take long-range potshots and murder infiltrators up close with flayers, while moving the Stalkers into a more mid range position to camp somewhere until it blows up (hopefully within range of enemies).

[01RTB01]

I also like the model but think they're too swingy for the cost.

 

For AT I'll be running dual heavy lokhusts as two pairs or a pair of them and 2 Doomstalkers

[Miek]

Likewise, the randomness is annoying. I ran them by 2 before with great success, but I think the terrain density in 9th is going to really hurt.

 

I'll probably run them again against horde armies, but probably a single one (with others heavy stuff that doesn't mind getting close and personal).

 

I really liked the small post-Indomitus, pre-codex era when you could MWBD any unit (and also could meet with people)... Too bad that didn't survive the codex. That removed some of its randomness. I don't have the codex in hand but I think you can't give it BS2 anymore, right?

 

Daughter awake, gotta go.

 

Edit: One thing I'm wondering is how it would work as a medium range tank with the interplanetary invaders circumstance of awakening. It's quite tough, and sure you'd forsake the high power profile most of the time, but you'd also get in range of the flayers and thus it could be a good distraction. I'm not sure it could be competitive, but I like the idea. Maybe other CoA would be better (especially if you have a warden around - Edit: N/A, warden only works on core). Haven't really researched it; just a thought.

Edited December 30, 2020 by Miek

[Get Thokt]

My local meta doesn't call for much anti-tank since the game rewards players who play the missions, thus anti-infantry weapons is where everyone is looking to.

 

They are a unit that mostly enjoys sitting back and making use of their range. So imo we have three other options that compete/support the Doomsday Ark (190). Canoptek Doomstalker (140), Heavy Destroyer (70), and Triarch Stalker w/ Twin Heavy Gauss Cannon (150).

 

Does anyone know how to calculate points per wound inflicted? I'd really like to give this one a go.

[01RTB01]

I don't I'm afraid. To be honest though I rarely find mathhammer "works". It's very rough and almost never plays out - things seem to massively over or underperform. Last game I played I over watched with 9 reapers against a primaris outrider and killed them. Chances are it won't happen but how many times have you missed a 4" charge or had 7 2+ to wounds come up as all 1s.

 

Maybe me but my dice are tricksy at best, at worst they're traitors

[Miek]

Does anyone know how to calculate points per wound inflicted? I'd really like to give this one a go.

I have a Python notebook to simulate shooting and generate graphs, it's pretty neat to visualize probabilities and reliability. I might give it a try tomorrow, I'm not super busy these days anyways (a lot of painting on my new overlord though). What would you like to plot exactly, points per wound on a land raider? Or on a MEQ?

[Get Thokt]

Mathhammer works by giving the best probability, then it's up to dice on the result.

 

I do feel that 3 Heavy Destroyers may be the better option here due to most Marine players I know leaning to Dreadnoughts with the -1 damage. That immediately hurts DDAs, Canoptek Walkers, and Triarch Stalkers where damage is already random.

 

The issue with Heavy Destroyers is when the target has an invuln save. But that's for another discussion.

[Get Thokt]

 

Does anyone know how to calculate points per wound inflicted? I'd really like to give this one a go.

I have a Python notebook to simulate shooting and generate graphs, it's pretty neat to visualize probabilities and reliability. I might give it a try tomorrow, I'm not super busy these days anyways (a lot of painting on my new overlord though). What would you like to plot exactly, points per wound on a land raider? Or on a MEQ?

 

That would be great! So I suppose it'll be vehicles in the current meta. Redemptor Dreds, Custode Telemon Dred, common SM transports (Impulsor & rhino), DG Blight-Haulers. If you have the formula to calculate these, I'd love to know it

[Miek]

You can find the code here: https://gist.github.com/miek770/d662a1307fd77f5f0f2cc3d9ccbf8229

Here's an histogram showing, over 10⁴ iterations, the points per damage done on a generic T7, Sv2, no invul. target (points/dam on the x axis, frequency on the y axis). The plots are stacked. Only the high power weapon is considered (ex.: the DDA's gauss flayers are ignored) and the LHD has the gauss option:



There's nothing particularly surprising here but it was fun. The randomness of the DDA and CD is obvious but what's missing here are the times when no damage is done, hence the pts/dam would be infinite. This happened roughly 20% of the time for the DDA, 30% for the CD and 60% for the LHD.

Ignoring 0-dam scenarios, the DDA has the highest mean pts/dam, at 51 vs 42 for the CD, and 18 for the LHD.

It might be more interesting to plot 2x DDA vs 3x CD vs 6x LHD and just look at unsaved wounds. They would all be on roughly the same points base and 0-dam scenarios could be plotted instead of ignored. Here it is (over 1³ iterations this time):



They yield an average nb of unsaved wounds of 11, 12 and 13 respectively (DDA, CD and LHD). That doesn't account for the DDA's flayers, the associated stratagems, and its resilience. I'm still curious about using it as a medium range tank as mentioned before. I don't want to to into too much details about the alternatives because they aren't this topic's focus, but they have their own stratagems and stuff they can benefit from to shift the balance.

I haven't included those here, but when you look at the individual plots (instead of stacking them), you can see the shift of the "curve" to the right for the CD & LHD, especially the latter. 6x LHD are definitely more consistant damage-wise, but that's no surprise and it doesn't account for other factors, as mentioned above.

That's it for now, I'm trying not to stray too far from the main topic (DDA), but let me know if you'd like to see some more data (ex.; detailed plots, statistics, scenarios considering specific buffs, etc.).

Edit #1: A histogram is not well suited for this; I should have used a line plot with a percentage instead of a frequency count but that would have required a small post-processing step. Next time.

Edit #2: That's better:

Edited December 30, 2020 by Miek

[Frostglaive]

Me personally, I won't be running a Doomsday Ark anymore unless its shots or damage becomes more reliable/consistent. It's just far too swingy for my tastes to be of use to me. 

 

The Gauss Arrays and Quantum Shielding (w/ stratagem support to make it a 4++) I definitely like about it. But the Doomsday Cannon itself... had it been either Heavy 3D3 or 3D3 Damage, I think I would take it. But D6 shots and D6 damage and having to remain stationary just to get that higher damage output? No thanks. Add in the fact that its BS degrades and gets no support anymore from MWBD, I'm going to pass.

 

I'd rather take a unit of Lokhust Heavy Destroyers instead. Far less durable unfortunately. But more reliable to hit w/ their built-in reroll 1's to hit, consistent amount of shots, does not have to remain stationary, and better damage output.