How is the overwatch to hit calculated?

[josna238]

I am worried because my Overwatcher Ranger with tracer, laser and hairtriger has an insane rate of success when overwatcing (to the point to kill a berserker by himself just on reinforcement).

What is the formula, for example:

Aim: 80
Laser
Tracer
Cool Under Pressure
Damn Good Ground
Steady hands
Advanced Hairtriger
Enemy blue movement
Enemy path by low cover
Alien Defense: 20
Weapon Range +8
Walk in smoke

I don't know what is the order in the fórmula, I mean it could be (i am inventing to ilustrate) "OW_Penalty*(Aim-Cover+Hightrigger)+Tracer+Laser-Defense+Range-Smoke"

[LordYanaek]

I have read the 70% reduction for OW is calculated last after everything has been added but was unable to actually find where it's calculated in the code. On other occasions i've read OW specific bonuses are added after the 70% reduction so Cool under pressure (and maybe hair triggers) would add their whole +10 and +5-15 rather than 70% of the bonus. Who's right ???
I'm almost sure the normal bonuses and penalties (tracer rounds, cover ...) are calculated before the 70% for overwatch but again i have no proof, it's just been considered a fact in every post i've read on the subject.

I would also like to know how exactly they add-up because it can make a difference when considering Covering Fire for instance.

[Tuhalu]

All hit modifiers are calculated together before applying the overwatch modifier.

The game gets around this with overwatch specific abilities like Cool Under Pressure and Hair Trigger mods by adding in a higher modifier that is equal to what it states after a blue move overwatch modifier is applied.

This works out something like (base aim + modifiers) * (1 - overwatch modifier) = final aim.

Note: The overwatch modifier is different depending on whether the target made a single move or dashed. This isn't usually terribly relevant, but in certain specific circumstances an enemy may dash (for instance, a stun lancer rushing across the map to stab you). In LW2, it's 0.3 for a single move and 0.4 for a dash move.

Code: Select all

REACTION_FINALMOD=0.3f
REACTION_DASHING_FINALMOD=0.4f

In the OPs example, you get: (80 + 5 + 5 + 15 + 10 + 10 + 22 - 30 - 20) * (1-0.3) = 60.9%

Not an amazing chance (end game characters normally have much more base aim and superior hair triggers exist), but you have about a 23% chance to hit with all 3 shots at those numbers. I'm ignoring the graze band and crit/dodge effects for simplicities sake.

Edit: There may be one specific ability that adds 10 accuracy after the final mod. The Fire Discipline leader ability:

Code: Select all

[LW_OfficerPack_Integrated.X2Ability_OfficerAbilitySet_PassiveAuras]
FIREDISCIPLINE_REACTIONFIRE_BONUS=10

The only way it could be working correctly is if it added 10 after the overwatch modifier.

[JulianSkies]

I have read the 70% reduction for OW is calculated last after everything has been added but was unable to actually find where it's calculated in the code. On other occasions i've read OW specific bonuses are added after the 70% reduction so Cool under pressure (and maybe hair triggers) would add their whole +10 and +5-15 rather than 70% of the bonus. Who's right ???
I'm almost sure the normal bonuses and penalties (tracer rounds, cover ...) are calculated before the 70% for overwatch but again i have no proof, it's just been considered a fact in every post i've read on the subject.

I would also like to know how exactly they add-up because it can make a difference when considering Covering Fire for instance.

Short answer: Overwatch-specific bonuses (Cool Under Fire and very specifically Hair Triggers because JL came by a thread and said they worked that way) apply their bonus after the 70% reduction.

Long aswer: Overwatch-specific bonuses actually apply a larger bonus than the stated value in order for their stated value to actually be what gets added in the end on an overwatch shot, because every calculation is made prior to the overwatch penalty. So for example an Advanced Hair Trigger, that gives +10 to overwatch shots, actually gives +14 so that when you multiply by 70% it actually gives +10 after rounding. However, since dashing has a larger penalty (60% instead) then they are affected by those additional 10% as well since they're calculated for a non-dash.
You won't find any AI enemy that will actually dash other than melee attackers, however.

[LordYanaek]

Thanks for the explanations, so in a way everyone was right.
So practically speaking, OW specific bonuses are applied fully unless the enemy is dashing (rarely relevant).

This means Covering Fire is not that bad if you combine it with OW specific bonuses.
With CuP alone, the break-even point is ≈ 35% to hit (below this you have better chance with an OW shot, above the direct shot has better chances). This is equivalent to a 80 Aim soldier targeting an enemy in high cover (with no defense bonus). In such a situation going into OW with CF and CuP means we have the same odds of hitting (not very good) but we might prevent him from moving to take a flank (or get a better chance to hit if he does).
However if Fire Discipline does add the entire +10 to hit it would push the break-even point to ≈ 65% (95 aim soldier vs enemy in low cover or 110 aim soldier vs enemy in high cover).

Suppression is even better with Lockdown + CuP. The break even point would be ≈ 85%. Anything below that means you'll have a better chance to hit with the Suppression reaction fire than a direct shot. If you add Fire Discipline the break even point moves above 100% chance to hit and you are always better using Suppression. Of course suppression requires that the enemy actually moves to trigger but you can get some really good chance to hit even with lowish aim.

I didn't consider Hair Triggers as Scopes would give the same bonus to a direct shot but a superior hair trigger means you can get up to 80% chance to hit with Covering Fire shots and have the same odds as a direct shot, but a Ranger can take 3 of those shots and a specialist 2 vs one single direct shot. Not that bad for a perk considered terrible by many players.
Nerf Covering Fire!
Just joking on that one, there are obviously tactics that don't want to rely on OW shots in the first place and it's still mostly a terrible perk when you get it from the AWC but in a dedicated OW build it probably have it's place.

[josna238]

This explain the absurd rate of success on my overwatch ranger (in a retaliaton during 4 reinforcements turns he did 12 hits and even killed a berserkerker by his own!) Because is a good aim ranger with tracer hairtriger, laser, High Damn Ground and all the OW path perks.

So I guess that all the shots he did were above 100% to hit.