If I understand the game info correctly, this is what happens.

Personally, I find that phase missiles from Vasari Assailants kill out hostiles noticeably faster than conventional missiles from LRMs.

Whats really evil is that Vasari bombers and fighters also use phase missiles. Bombing runs with phase missiles against capitals can be powerful.

There's a lot of contrary information being posted here as fact.

- The phase missiles DO/DON'T ignore "shield mitigation" on hull damage. Lots of contradicting statements with no proof.

- Ships CAN/CAN'T be killed with shields up (OP had not seen this, but other people have seen this happen so we can probably say CAN).

Gameplay tests show this to be true. You can test yourself because when the shields are all the way down, every once in a while, the shot will hit for seemingly triple damage, because it's bypassing all of the mitigation. There's no way to really prove this without video capturing in game footage.

Phasing is extremely effective. Take for example the following:
Ship A with 1000 shields and 1000 hit points
Hull and shield regen of +2.0HP/sec
Shield Migration of 15% to 50% when below 200HP
Armor of 2

Neglecting all armor, hull regeneration, shield mitigation, and shield regen.
Normal attack will have to do a minimum of 2k of dmg to take out this ship A.
Phase missile attack with 25% phasing will still need to deal 2k of dmg to out ship A.

With only shield and hull regeneration, Normal attack > Phase attack. For this example, phase missiles can take up to +15% more time to destroy ship A (reason being that phasing initiates both regen)

Now if we bring in shield migration and armor, phase missiles are up to +30% more effective than normal missiles. This of course depends on how the phase % and the rate of dmg against the target.

~For ship A under 40HP/sec of dmg, it takes 98.6sec for normal missiles dealing 3,944 dmg and 74.5sec for phase missiles dealing 2,980 dmg.

~Under 300HP/sec (roughly 23 Assailants or 27 LRMs base dmg) normal attacks takes 11.4sec dealing 3,420 dmg and 8.0sec for phase missiles dealing 2,400 dmg.

All numbers above were determined with derived algebraic expressions (too complicated to type) assuming full, upgraded phase of 25%, instant damage with the shield/hull modifiers above for the sake of comparison, and 100% dmg to target.

Even against armor tanking targets, the ability to skip a bit of shield migration grants you a portion of dmg you would have lost against or when hitting hardened shield tankers, this would be your only hope.

Hope this helps. This has cost me yet another hour of my night.

Well the way it works in my head, phase missles are worse than a regular damage upgrade.

Heres my logic and calculations, could be wrong.

Lets say something(A) deals 10 damage. A fully upgraded (A) deals +30% more damage, thats 13 damage. Compare this to something (B) that has 25% phase capabilities and the base of 10 damage.

So I'm going to assume the target is at full mitigation (60%) for these.

Against 60% mitigation, (A) does 7.8 damage when fully upgraded.

Against 60% mitigation, (B)'s missiles will phase 25% of the time, so 25% of the missiles will do the full 10 damage. So thats .25*10 = 2.5 , and the other 75% of the missiles will be doing regular, mitigated damage, and thats .75*10*.6 = 4.5 , add the 2 together and you get 7.0

(A) does 7.8 dmg/second and (B) does 7.0 dmg/second. Even when the mitigation isn't 60% and it's lower, the benefit goes to (A), because bypassing mitigation at lower %'s gives you even less of a damage bonus over regular hits.

This is all assuming phase missiles can't bypass armor, but can bypass shield mitigation.

As the readme dont counteract the manual so I think it does applies to hulls as well (as this is where it be if it was changed).

As for what best it depends on shield health and medidation compared to hull armour and hitpoints. In fact it only when shield to hull effective hitpionts is 1:1 that a 30% damage boost and the 25% medidation are equal no different in shots unless hp/damage ratio is 1000:1 then the 30% damage wins just (by about 1 shot less).

Since it about effective hps it can be used on any craft for any shield and armour medidation and health.

Assuming shield and hull regen at same rates. (If shield regens faster than the hull shield to hull ratio need to be adjusted ie to 1:2 to keep the break even the same.)

Chasington:

First, I never did get around to testing phase missiles myself, but ASSUMING these are the right mechanics, your math is still wrong:

60% Mitigation means only 40% damage is getting through -- you should be multiplying by 0.4. Your numbers are correct for 40% mitigation. At 60% mitigation we get:

(A) = 5.2
(B) = 5.5

If mitigation is 80%:

(A) = 2.6
(B) = 4


This just shows that if phase missiles bypass mitigation, they are more effective in proportion to the amount of mitigation they encounter. I only provide the 80% number to demonstrate this -- I don't actually remember what an Advent capital with the shield mitigation upgrade tops out at, but it is pretty high.

Finally, the phased missile damage hits the structure of the ship. There is a tactical use for phase missiles in situations where Guardians and Progenitors are keeping your target alive by constantly augmenting or replacing its shields.