How much armor should a ship have? How does this vary by role and tech level?

[Iestwyn (OP)]

Yet another question on ship design theory. What's the basic idea behind how much armor you put on your ships? Obviously the ones you expect to be targeted will get more armor, but are there any rules of thumb that you guys use? Any underlying theory?

Thanks in advance!

[nuclearslurpee]

Not a lot of theory involved, I think most people fiddle with their armor values once they've got the propulsion and weapons fitted.

The main thing you need to think about is what you're designing protection from. In most cases this means missiles - missile ships need to survive an exchange of fire, while beam ships need to survive some hits until they can close the range. A rough rule you can use is to put enough armor on a ship to survive missile hits equal to what you could expect from an ASM either at your tech level or one higher (the latter being more expensive, but also more future-proof and better against certain flavors of high-tech NPRs you might run across). Essentially, since missiles have a maximum armor penetration equal to the square root of their damage rounded down, you try to anticipate the damage an enemy missile could do and put on enough armor to ensure that a missile won't penetrate - it might reach the last layer of armor but won't do any internal damage.

This gives you a decent rule of thumb for a minimum amount of armor, but in practice you'll need more as ships get larger, engagement ranges get longer, missiles and launchers get faster, etc. There's some statistical work that's been done but I'm not aware of a good general model for how many hits from N-damage missiles an X-by-Y armor belt can survive before internal damage is probable. Additionally, beam ships will need heavier armor if they expect to get into brawls with other beam ships, especially if the enemy has lasers or, worse, particle lances. At some point, you start to get a feel for how your armor matches up against different NPRs, assuming you're not just killing them immediately, so you can start to tailor your designs a bit.

As a rough rule of thumb, it may make sense to set as a fleet doctrine a certain percentage of the ship's tonnage dedicated to armor, which will naturally lead to thicker armor as you research better techs. Anywhere from 10-20% is a decent starting point, so I suggest picking something that sounds reasonable and seeing how it works out (and if it doesn't, learning from failures is how Aurora is played, after all).

[misanthropope]

armor "just because" is a disaster IMO.  propulsion and housekeeping can easily take half of your total volume, and "10-20% armor" reduces your throw weight and point defense by A. THIRD.  wading through 100 or more salvoes of missiles in a battle is kind of the most ordinary thing there is- surviving that by grace of armor instead of point defense is an extraordinarily expensive exercise in masochism.

generic beam ships get kicked in the teeth even when things go as planned, those guys need armor for real.  equal tonnage to armor as weaponry is a sensible first approximation.  but if you've got the sense to bring a gun to the gunfight, you probably want to wear something other than plate mail to the occasion.

[Garfunkel]

Armour is, of course, a necessity because there is always a small chance that a missile slips through your AMM & PD and you don't want to lose a ship to single unlucky strike. But as misanthropope said, the idea that all ships get 10% of their tonnage as armour is flawed.

1) It's entirely possible that you do not take any damage in a battle. Because your missiles have a longer range or your PD is just that good. In fact, it would be better to build more PD ships that can double up as beam sluggers and/or planetary bombardment ships than to put more armour on your missile combatants.

2) Operationally, shields are better than armour since it'll replenish itself and as long as the ship survives, it doesn't need to go back to a shipyard for repairs - everything can be fixed at the field with enough MSP.

However and always in Aurora, it's not quite as straightforward. Armour gives better protection ton-per-ton than shields and it's cheaper as well. For dealing with NPR/spoiler that uses AMM spam, an armour ball tank is the cheapest option to literally soak the missiles.

And of course, whether you're playing solo against spoilers, solo against NPRs and spoilers or running a multi-faction game, means different challenges facing you. 4 layers of armour is fine at an early tech game focusing on the Sol system. 20 layers of armour might not be enough for certain late-game encounters.

[liveware]

Knowledge of your opponents weapon systems is invaluable. For example I am currently building six armor-layer beam warships against an opponent who uses laser weapons which typically deal 2 or 3 damage per shot. I haven't encountered any of this opponents missile ships yet (maybe they don't have any?). I have gotten into several minor engagements involving no more than 4 ships at a time and I have yet to lose a ship. Typically my beam warships will take extensive armor damage but are able to defeat their opponents before taking internal damage. The exception are my scout/survey ships which have only 2 armor layers. These often get ambushed at hostile jump gates by strength 2 lasers and take internal damage more often than I would like. I think it's only a matter of time until I lose a scout to a lucky engine hit. My warships are doing just fine though so it is unlikely that I will add more armor to those, though I will likely add some shields during their next major refit session.

Armor tech level is pretty significant early on in my opinion as early tech armor is extremely heavy. Higher tech armor is lighter but provides the same HTK per armor plate. I usually pursue composite armor as fast as my research capacity allows before engaging in any major hostilities.