ReRolls, Sustained Hits, Lethal Hits, and You
[Note: I originally wrote this article for the Drukhari subreddit but wanted to port it over here.]
I've been playing around with the Reaper's Wager detachment and all of its tools. So far, I'm a big fan. However, this is my first time playing an army in 10th that has the option to gain Sustained Hits or Lethal Hits at will, let alone having to pick between the two. I've been doing some digging and collecting information about the statistics of it all, along with figuring out how it applies to Drukhari or at least typical Druk units. Mooost of this information comes from Goonhammer's articles found here and here if you want to see all the numbers but if you just want basically the tl;dr of that article, I got you covered.
/// TL;DR
Sustained Hits is better when you're Wounding on a 2+ or 3+
Lethal Hits is better when you're Wounding on a 5+ or 6+
They’re tied if you’re Wounding on a 4+
If you have Devastating Wounds, the equilibrium shifts so you're usually favored to do Sustained Hits while having Dev Wounds except for when you'll be Wounding on 5+.
In actuality, Sustained Hits is always better than Lethal Hits on Scourges with Haywires
There is a point where Lethal Hits is slightly advantaged but against niche targets and you remove the possibilities for dice spikes for a minor statistical advantage
Basically only fish for Lethal Hits when you will be Wounding on 6+
Never fish for Sustained Hits unless the number of hits gained per sustained is equal to or greater than the number you're hitting on (Like Lelith hitting on 2+ while having Sus 2)
When to fish doesn't change much even if a unit like a Court gets Lethal + Sustained except for the Archon - they should always fish if they have both effects
This is just in regards to odds with fishing, obviously the combined effects are still very strong together
/// When to pick [Lethal Hits] vs [Sustained Hits]
When comparing the two, it doesn't matter what your unit HITS on. It could be a 2+ Archon or a 5+ Smoked Kabalite. What matters is what those attacks would WOUND on. ReRoll Hits from a Pain Token do not change this.
The end results of the two is equal if you are Wounding on 4+.
Sustained Hits is better when you're Wounding on a 2+ or 3+
Lethal Hits is better when you're Wounding on a 5+ or 6+
The math here has to simply do with looking at the equilibrium point of where the two statistics cross. That would be when Wounding on a 4+. It doesn't shift if you can Crit on 5s or better. It does change very linearly if you up the Sustained Hits X. For example, if you go up to Sustained 2, then the equilibrium point is wounding on 5+. However, in their current state, we have no way to choose between Sustained 2 vs Lethal so it doesn't apply.
/// When is it worth fishing for [Lethal Hits]?
Currently, we don't have a way to Crit on a 5 so this math only looks at Lethals on 6s. What you Hit on kiiinda doesn't matter, barring two exceptions. What matters most is, again, what you Wound on. These first few apply to both No ReRoll Wounds at all and ReRoll Wounds of 1 from something like the Detachment Rule.
If you will be Wounding on a 6+, it's always worth fishing for Lethal Hits
If you will be Wounding anything else, it's statistically disadvantaged except for...
If you are Hitting on 2+ and Wounding on 5+ it's worth fishing for Lethal Hits
Lastly, this doesn't 100% apply but keep in mind, if you Hit on 3+ and Wound on 5+, the odds are the exact same if you fish or not, so adding another effect could sway that into positive. We’ll come back to this.
If you have ReRoll All Wounds from an Archon Pain Token or say Twin Linked on Talos, the above gets even tighter. Those ReRoll Wounds reduce the need for Lethals.
If you have ReRoll all Wounds, it's only worth fishing for Lethal Hits if you're both Hitting on 2 or 3+ and Wounding on 6+
So if you go charge with an Archon Court Kabalite unit and are wounding on 5's with a Pain Token, it's actually not statistically worth it to fish for just Lethal Hits
Or for example, Talos should never fish for Lethals because they hit on 4+
/// When is it worth fishing for [Sustained Hits]?
There's an easy formula to remember for this one. Hitting on X+ and having Sustained Hits Y:
If (Hitting on) X + 1= Y (Sustained Hits gained), it's a 50/50 so up to how bad you need to gamble.
If X + 2 ≥ Y, it's never worth it.
If X ≤ Y, it's always worth it.
If you don't like math formulas:
Basically, if what you Hit on is 1 more than the number of hits gained in Sustained, you have statistically equal results to fish or not - you decide on coin flipping | Ex: Archon hitting on 2+ with Sustained 1 or Kabalites on 3+ with Sustained 2 (Skysplinter) is a 50/50 gamble
If what you Hit on is 2 or more than the number of hits gained in Sustained, it's just not worth it to fish unless you absolutely have to go for the big gamble | Ex: Kabalites hitting on 3+ with Sustained 1 should almost never fish for Sustained
But, if what you Hit on is Equal to or Less than the number of hits gained in Sustained, it's always worth it to fish. | Ex: Lelith hitting on 2+ with Sustained 2 should always fish for Sustained
This one is really simple. It comes down to what you're hitting on and how many hits you gain from Sustained. For the odds to work out, it's a very uncommon occurrence outside of Lelith. If hitting on 3+, you have a 2 in 6 chance of missing and have a 1 in 6 chance of getting a Crit to add 1 for a net negative. Now if you're on 2+, those odds are equal, so it then comes down to if you want to flip a coin.
/// When to pick [Lethal Hits] vs [Sustained Hits] when [Devastating Wounds] is involved
This would apply to units like Troupes that add Dev Wounds to the mix. The key stats are what we're Wounding on and what the enemy save is. As per above, what we hit on doesn't apply outside fishing.
Ultimately, the equilibrium point moves from "Wounding on 4+ regardless of Save" to arooound "Wounding on 6+ against 4+ Sv" but it's a bell.
If we're Wounding on a 2+ or 3+, Sustained is always better
If we're Wounding on a 4+, Sustained is better when the saves are on a 2+ or 3+
But if we're Wounding on a 4+, Lethal is better when the saves are a 5+ or 6+
If we're Wounding on 5+, Lethals is better besides a 2+ save
And lastly, if we're Wounding on 6+, we circle back to Sus on 2+/3+ Save, tied for 4+ Save, and Lethal for 5+/6+
If you need a succinct way of remembering it, even if not 100% accurate, Sustained Hits is favored in 75% of possible combinations. Lethal wins out when Wounding on 5s.
/// When to pick [Lethal Hits] vs [Sustained Hits] when [Devastating Wounds] and [Anti X] are involved
This is in regard to units like Scourges that add the very powerful combo of Anti X to Dev Wounds. The numbers on these get a bit wonky as we look at different Anti X numbers. For that reason, to keep this simple and a tl;dr, I'm going to just explain Scourges - the most common thing in our army for this to apply to. When combining Devastating Wounds on Anti-Vehicle 4+...
Very similar to looking at Lethal Hits vs Sustained Hits, it now applies to Saves the enemy would make on the Lethal Hit attacks.
With Dev Wounds and Anti-X 4+, Sustained Hits is better when your target would be making saves on a 2+ or 3+ for the non-Dev Wound attacks
With Dev Wounds and Anti-X 4+, Lethal Hits is better if your target will be making saves on a 5+ or 6+
It's surprising at first until you realize it's you needing a 4+ up while your opponent needs a 5+ instead. But keep in mind, because it's their roll, they could CP re-roll it.
And to give a sense how wonky Lethal Hits can get, Lethal Hits when the target would be making saves on a 2+ is legitimately detrimental. It averages 5.31 damage while a clean Scourge averages 6.
A big grain of salt here though is how rare it is for a Scourge to be both proccing Anti-Vehicle 4+ while that Vehicle is saving on a 5+ or 6+ even with the AP-1. Either way, it's interesting stuff.
Using Scourges as examples,
With Sustained Hits 1, they average 2.66 attacks going through for 7.98 damage average
With nothing, they average 2 attacks going through for 6 damage
With Lethal hits, they get a lower average of 1.33 attacks going through
However, there is admittedly the feel here and opportunity cost. If you go with Lethal Hits even if statistically better, you remove all opportunities for a Sustained Hits spike. The odds may say your average damage output against a tank saving on 5+ will be higher, but you’ve also removed all odds of those spikes where you get even more wounds in than you shot. Our average may be worse but our possibilities are better. Ultimately, that will be a decision up to you in the moment. Personally, I’ll still go for the Sustained Hits because in the end it’s a game and those big spike moments are what we remember fondly.
/// What about fishing with a unit like the Archon + Kabalite + Court unit being able to have [Lethal Hits] & [Sustained Hits] aaaand ReRoll Wounds from the Archon Pain Token?
This gets pretty specific but is probably more likely to happen than you think. It doesn't change too much from the [Lethal Hits] results above but remember when I said adding another sway effect could sway a result?
If you will be Hitting on a 5+, it's never worth fishing even with the combined Lethal Hits & Sustained Hits. Though this would only apply to our Kab Dark Lance getting -1 to Hit from something like Stealth.
If you will be Hitting on a 4+ but Wounding on a 6+, it's always worth fishing for the combined Lethal Hits & Sustained Hits
If you will be Hitting on a 2+, it's worth fishing for the combined Lethal Hits & Sustained Hits no matter what you're wounding on. So our Archon should always fish if we have both buffs.
Note that while adding Sustained Hits doesn't offer much more in terms of when to fish, all of those success chances for the fishing we would do anyways went up 3-14% each. For example, Hitting on 2+ and Wounding on 5+ went from 39% chance to a 44% chance of forcing an opponent's save.
Thank you for reading and making it this far! Happy hunting!