Deflector Screens vs Missiles

[Alan Harper]

When calculating the damage from a missile salvo, at what point do Deflector Screens take effect?

Are deflector screens applied after armor but before the missile effect/salvo multiplier?

Or are deflector screens applied after the missile damage has been multiplied?



The discussion in this thread goes into when Deflector Screens are applied for non-missiles attacks.

T

Post in thread 'Damage Multiplier in the new HG, or One Shot, One Kill'

Aug 17, 2022

But does the Weapon damage multiplier go on before or after the Deflector roll?
and to clarify, the dice for the deflector(s) are combined to roll the check and that effect is multiplied by the count of the dice rolled to reduce damage, so an 8 is zero, and two deflectors against one attack with a check of ten reduces damage by 8?
The wording is a bit obscure and until reading MyndkryM's post and re-reading the box, I was thinking you rolled the dice and used the roll to reduce damage, like weapon damage.

My read is that screens go *before* multipliers. See p29, Damage Multiples...

• Tupper

• 

The section on damage multiples indicates that "other countermeasures" (Deflector Screens?) are applied before the damage multiple.

However, the multiplier for basic missile damage calculation is a different mechanic from the section on damage multiples for barbettes and bays, so I do not think this section is relevant to my question.



Missile Impact from page 173 Core
"If an attack roll for a missile salvo is successful, the target will sustain damage. Roll for damage as if for a single missile and deduct the target’s armour as normal but do not apply the Effect of the attack roll. Instead, any damage is multiplied by the Effect of the attack roll but the Effect cannot be higher than the number of remaining missiles in the salvo."

DEFLECTOR SCREENS page 82 HG
"These are energy-based screens projected away from a ship to deflect incoming attacks and reduce the damage they cause. Deflector screens mitigate damage from any weapon, reducing its damage by 1D (multiplied by the Effect of the angle screens action)."

DAMAGE MULTIPLES page 29 HG
"Barbettes, bay weapons and spinal mount weapons have damage multiples. After a hit is scored, roll damage, subtracting armour and other countermeasures from the total. Be sure to note the AP score of the weapon if it has one. Multiply the remaining damage by the Damage Multiple for the final damage. Damage multiples do not apply to missiles and torpedoes, which apply damage as normal."

 

[Arkathan]

The next paragraph in Tupper's response covers the deflectors.
and other countermeasures.
So you deduct armor, keeping in mind any AP, then apply other countermeasures.
Then you multiply by the effect of the attack, but limited to a max multiple equal to the number of missiles remaining in the salvo.

 

[Sigtrygg]

So a screen several metres from the ship hull takes effect after the weapon has hit the hull and been reduced by armour?

Surely it should be deflectors reduce the damage first then armour?

 

[Arkathan]

I only stated it that way so that AP was used up, preventing someone from trying to AP their way through a screen by adding it all together prior to using the AP of specialized munitions.

 

[Limpin Legin]

It is more subtly detailed than that, because missiles don't hit Target the moment they are fired as part of the Attack action. Here are what appear to be the salient points from the two rulebooks:

The standard skill check used when making an attack from a spacecraft is as follows.
2D + Gunner (appropriate speciality) + DEX DM
Core Rulebook, pg 167

Countermeasures: As missiles can take several rounds to reach their targets, you should keep track of how many missiles remain within each salvo, reducing them as countermeasures take effect.
Core Rulebook, pg 173

When a missile salvo reaches its target, the missile makes an attack roll as normal in the Attack Step. However, neither the Gunner skill of the Traveller(s) that fired the salvo nor range are used as modifiers. Other modifiers, such as Evasive Action, are used as normal.
Instead, the number of missiles remaining in the salvo greatly affects their chances of making a successful attack. Apply DM+1 to the attack roll for every missile in the salvo.
Note that missiles almost always have the Smart trait (see page 79). For missiles, use the TL of the missile itself or that of the attacking ship, whichever is greater.
Core Rulebook, pg 173

Screens use the Gunner (screen) skill and the Angle Screens reaction against specific attacks, ...
High Guard, pg 40

Angle Screens (Gunner): Using a screen, a gunner can attempt to deflect or reduce damage from incoming attacks. The gunner must succeed at a Gunner (screen) check against an attack and, if successful, reduces the damage of the attack – after armour has been accounted for – by the number of dice rolled by the screen (as noted in its description), multiplied by the Effect of the gunner’s check.
High Guard, pg 41

Deflector Screens: These are energy-based screens projected away from a ship to deflect incoming attacks and reduce the damage they cause. Deflector screens mitigate damage from any weapon, reducing its damage by 1D (multiplied by the Effect of the angle screens action).
High Guard, pg 82

Or, if in doubt, look ahead:

Resolve damage as you would for a missile salvo, rolling once for damage, applying any armour and screens, and then multiplying by the effect.
High Guard, pg 103

For further qualification what "effect" means in Traveller:

Effect: For most situations, the only thing that needs to be determined is whether or not the Traveller succeeds. If the Traveller’s total throw after applying all Dice Modifiers equals or exceeds the target difficulty (eight or more for an Average check), they succeed. If it is less, they fail.
Often, however, it is important to know how well the Traveller did – or how bad. To do this, subtract the target number from the dice roll of the check, including any modifiers. This margin of success (or failure) is the Effect that can be consulted on the Effect Results table. This is also used in combat to calculate damage (see below). ...
Core Rulebook, pg 61

 

[Condottiere]

Considering the short range of deflector screens, they should only have an effect on the final approach.

 

[rinku]

As written, the "Angle screens" rule would seem to answer the question, as it explicitly says to reduce damage after armour has been applied. Since this definitely happens before any damage multiplier, it doesn't really matter much which order they are applied. Do shields first if you like.

(Possibly it was written that way because standard screens are mostly preventing radiation? Meson guns ignore armour anyway, and dampers are going to help even if the nuke hits. Maybe.)

I'd also note that how a missile salvo's damage is resolved is somewhat abstracted anyway. You end up with a roll to see how big the boom is and a roll to see how well the shields reduced that, and if armour and shields stopped the base damage the multiplier doesn't have any effect.

 

[MasterGwydion]

I house rule this. Screen Effect is before Armor Effect. It hits the screens before the armor.