It still needs a lot of tuning based on feedback, but:
A) Most actual ship stats are computed during application-init based on a balance formula that uses categories for stats. A short-range weapon gets 1x dps, a long range weapon gets 0.3x dps (or something like that). A normal-speed ship gets 1x dps, a slow-speed ship gets something higher. A ship with the "MildTank" durability class gets less dps and more hp, and a "MildGlassCannon" gets the other way around.
The difference between a fighter and a golem is the value in "strength" field. At root, that strength number is just a multiplier into the above formulas.
And that "strength" number is also the basic budget unit used by the AI when it pays for things, and it also underlies the resource costs the human players pay.
the hull system, armor system, immunities and damage types.
B) Immunities are gone in general, replaced in most cases with a less-binary approach. For example, a tractor's capacity is now measured in "strength of tractored units" rather than count, and if it doesn't have enough to stop something it will slow it down.
C) As for the hull system, armor system, and damage types, that's all been folded into a new system, which is best illustrated by the example:
1) Many objective units use the "Structure"
defense type.
- "Structure" "costs" less in the balance formula than the other defenses, so it's the cheapest way to lots of hp.
2) Bombers use the
weapon type "Fusion Bomb" which is good against structural.
- "good against" simply means "does 4 times as much damage as normal"; doesn't matter which weapon type or defense type, it either gets 1x or 4x.
- Fusion Bombs are always short-ranged, but Fusion Rockets (used by MLRS) are medium range, and the Railcannon (used by Sniper) are planet-wide range, and both are good against structure.
3) Bombers themselves use the "Armor" defense type.
- So other bombers don't get a bonus against them.
- Also, the only weapon types good against armor are short-ranged, so it's harder to murder bombers from a distance.
4) Fighters use the "Armor-piercing shell" weapon type, which is good against armor.
5) Fighters themselves use the "Evasion" defense type.
- So neither Bombers nor Fighters get a bonus against them.
- But both there are both medium and long ranged weapon types that are good against fighters, so they're easier to kill from range.
- On the other hand, no short-range weapons are good against evasion, so fighters will tend to out-dps other knife-fighters head to head.
- Also, evasion halves the effect of debuff damage like engine-damage, paralysis, zombification, etc.
6) Missile Corvettes use the "Guided Missile" weapon type, which is good against evasion.
6) Missile Corvettes use "Structure", so bombers are good against them.
- They're also in the "MildGlassCannon" durability class (to keep their dps up despite being long-ranged), so they're very easy to kill.
- Which is why you probably want them to be protected by a nearby Shield Starship.
7) Shield Starships use the "Shield" defense type, which is roughly equivalent to AIWC's forcefield mechanic.
- Shield starships are also in a special durability class that gives them practically no dps but a ton of hp.
- Shields also negate debuff damage (engine-kill, paralysis, etc)
- There are both long-ranged and short-ranged weapons that are good against shields, but the long-range ones only come on large ships and the short-range ones are mostly on semi-exotic fleet ships.
- If a unit's shields are completely down, the remaining hp acts like "Structure" defense type.
Siege Starships use the "Plasma Torpedo" weapon type, which is good against Shields
- It's also an aoe weapon, so it can clean up clouds of glass-cannon ships even if they're not shielded
9) Siege Starships are also Structure (and, iirc, full-glass-cannon), so again you'll want external protection for these, and losing one hurts a lot more than losing a missile corvette (which can be replaced in-the-field by the Ark or a Flagship).
To recap, you could think of it as "hull type", but now there are only four: Structure, Armor, Evasion, and Shield. Each of the four is distinguished in more ways than just damage.
D) All those durability classes, weapon types, defense types, and the dps multipiers for each category, etc, are defined in moddable xml. The goal is to balance vanilla, of course, but this makes it easier for players to contribute empirical data on potential changes.