Bear with me, this will be a long post, with lots of images (as they say, a picture is worth a thousand words.)
According to the pop-up text in the Shipbuilder, if the Average Armor Value (AAV) of a ship “is greater than the armor penetration value of a weapon, it will reflect 97% of that weapon’s fire without any damage.” This seems pretty straightforward. The AAV is continuously updated as you build your ship, and handily displayed in the lower right corner of the screen for your reference. Adding additional armor plating seems to have diminishing returns. I can’t put more than 6 or 7 armor plates on a Dreadnought before the AAV starts going DOWN with additional plates, rather than up.
Now, take this ship design (not my design; credit goes to alix965 for posting the challenge that I noticed this in):
It lists an AAV of 10.24, which seems pretty lackluster. Most weapons should have no trouble penetrating that armor value.
Wait, so what’s happening here?
A Heavy Beam Laser, with an Armor Penetration of 25, has hit the ship, but failed to penetrate the armor. Hmm. That’s weird.
Let’s try an even heavier weapon:
That’s a Particle Beam, with an Armor Penetration of 30 (the highest currently in the game), also bouncing off the ship’s armor.
This was the point at which I started to get curious. Obviously, if the ship had a higher in-game AAV, then it was being calculated differently than the stat the Shipbuilder gives you. I suspected that the game was still using the GSB1 formula: Total armor points, multiplied by hull bonuses, multiplied by stacking modifiers, divided by number of module slots actually used on the ship design.
So I designed a hull, calculated the armor value using the GSB1 formula above, and labeled it. As an added bonus, I wanted to test whether the in-game formula was applying the stacking penalties to the first armor plate or not, so I picked a value that would give me a 31 AAV without stacking penalty, or a 26 if the stacking penalty was applied (even though there is only one armor module on the ship hull). Here’s the hull in Shipbuilder, for reference. Note that the listed AAV isn’t even CLOSE to what the in-game AAV is:
And here’s the hull getting blasted by a Particle Beam, with 30 Armor Penetration (sorry about all the purple nebula clouds):
As you can see, the in-game formula is applying the stacking penalty to even the very first armor module, which means you’re really not getting your money’s worth when you add armor to your ship.
For funsies, here’s a second iteration of the Particle Beam test, with a target dreadnought configuration utilizing two armor modules, to check whether the the armor stacking penalty is being applied linearly or geometrically:
Answer: It’s geometric, at least in-game.
(Where H is the hull armor modifier, M1p is the first armor module multiplied by its stacking penalty, M2p^2 is the second armor module multiplied by the square of its stacking penalty, M3p^3 is the third armor module multiplied by the CUBE of its stacking penalty, etc, and n sub M is the total number of modules actually installed on the ship hull.)
This is basically the formula used in GSB1, except that in GSB1, the stacking penalties for armor were generally around 0.97. This meant that even at your 10th armor module, that module was still providing nearly 75% of its rated armor protection. However, with a stacking penalty of 0.85, by the time you get to your 10th armor module in GSB2, the in-game performance is less than 20% of the rated armor value for that module alone.
So, where is that number in the Shipbuilder coming from?
Answer: Here’s the formula:
(H sub n in this formula is the total number of module slots on the ship hull, filled or not. For some reason, the Average Armor value adds one to this “number of modules” value before using at as the divisor.)
Now, normally, I’d be a little put out by the second formula. You see, it penalizes ALL of your armor modules every time you add another armor module to the ship. That’s why you can’t seem to get an AAV higher than the 18-20 range in Shipbuilder - adding additional plating after that will actually make your AAV go DOWN because the new plate adds a penalty to every plate before it, not just a penalty to itself. To be fair, the Shipbuilder formula is correctly ignoring the stacking penalty for the first armor module installed, but it snowballs pretty quickly after that.
But, as I showed in the first part of the post, the game isn’t even USING that AAV that’s being calculated and shown in Shipbuilder, so… why get mad?
The Average Armor shown in Shipbuilder is a complete garbage number - it doesn’t reflect in any way, shape, or form, what the actual in-game armor value of your ship is. Cliff, why???