Are System Defenses worth the Science, Industry, Dust Upkeep, and Opportunity Cost for what you get? I've never felt they were.

I've got close to 500 hrs in ES2 and I'm comfortable playing on Endless difficulty (etc). I've never played a game of multiplayer though. I virtually never build System Defenses. Are System Defenses mostly a MP thing?

I do think the baseline System Defense of 200 manpower does become precarious, but in my experience, building ships (as needed) is a far more valuable (and versatile) use of my FIDS.

In MP though, I can imagine its tactical to try and threaten someone into building them (keeping them honest) otherwise you can snipe off a few 200 System Defense locations with a fleet that is designed for it. Is that a thing?

It is a thing even with AI, who stacks few fleets and then might roll over your system in one turn. You are probably very aggressive and take the fight to AIs territory early, so you have no opportunity to experience sieges on you systems and how defenses drag them.

Sublustris wrote:

It is a thing even with AI, who stacks few fleets and then might roll over your system in one turn. You are probably very aggressive and take the fight to AIs territory early, so you have no opportunity to experience sieges on you systems and how defenses drag them.

Other than a few agressive tactics (using my explorers to guard/kill undefended AI outposts) I am actually fairly passive and perfer peaceful victory conditions. Typically, I only build ships when pressured, and rarely (if ever) System Defenses. Even when next to a Craver or a Hisho, I question the value of System Defenses (at least in single player).

My thinking is this:

• System Defenses eat up FIDS that could otherwise go to the development of bigger FIDS (opportunity cost). Having bigger FIDS than the other guy is fundamentally how you win this game
• Therefore, something has to threaten my FIDS for me to redirect my resources into preventing the loss or reduced growth of them
• You can defend yourself in two ways: System Defenses or Ships.
• For a System Defense to protect my FIDS from an imminent threat someone has to traditionally invade my system in ground combat, but siege bypasses System Defenses. My value in building System Defenses is greatly reduced (damage to the attacker, additional ground forces, etc) from siege. The only value that remains is extending the time it takes for siege to chew through my Defense manpower.
• But time will not win me anything in itself (other than not being one shotted through 200 defense manpower). Ships win. So just build ships - they are versatile for other purposes as well and no one can invade you until the skies above have been won.

But furthermore, diplomacy can manage a lot of threat to my FIDS and provide additional value beyond not being attacked.

imo they're essentially just a safeguard against being caught unprepared. If an opponent declares war on you and you didn't have the time/resources to get ready for it, they could blow away systems right next to their own with normal combat fleets, since the medium-sized ships typically have enough default manpower to take an unguarded system on their own. Therefore, placing defenses on systems that are near potential enemies could prevent any unfortunate losses if they get the jump on you.

Additionally, any system upgrade that increases manpower conversion rate will help you on the offensive, since you can use it to restock ships more quickly.

They're pretty useful on systems that you can't really prevent hacks on reliably.

They are worth it. In the early game they can give you time to protect your system in the other way. Also, with proper setup I pretty often manage to destroy enemy forces on my planets... It may be less effective in the late game, but still pretty usefull. Also, there are occasions, when you have some bonuses based on your troop`s. For example, that one, that gives you additional production based on your garrison...

Donalejandro wrote:

Also, there are occasions, when you have some bonuses based on your troop`s. For example, that one, that gives you additional production based on your garrison...

Yes, the Vaulters can also utilize it on their 50 pop bonus where garrisoned troops add to their science output.

There's the mentioned vaulter bonus and the sim camps system development (well, it's a curiosity reward). If you have either avaiable then it's well worth the industry for the fids bonus alone.

The shield improvement reduces development damage, which is handy when an attacker uses orbital bombardment/blitz tactics.

Systems can be taken in a single turn or very few turns, on the other hand, the AI doesn't know how to properly besiege a system. So if you build system defenses before they arrive at your system, you can last dozens of turns. You might even beat the invasion back entirely, leaving them with an empty fleet and allowing your planet to rebuild food.

I tend to use them on factions such as horaito, where i know i'll reach a critical point where my growth will outpace my enemies, but where i am aware that early on my fleets will be weaker than theirs (depends on the situation of course).

I think they do their job very well up to the point where the above mentioned point "It's CP vs non repeatable system improvements" matters.If the enemey has a fleet of OPex Gear ships then your system defenses are a moot point, and you're likely not going to get much use out of the stuff beyond era 2 because by then you really have to intercept invasion fleets or reconquer systems. But the first 3 defense developments can successfully hold off AI on their own for quite a while, and increase the duration required for an enemey to invade. Granted, you should only build them on systems you expect to get invaded, and other techs might be more useful.

Fun trick while we're on the topic:
Enemey ships remove all their troops at the start of the turn in an invaded system, so unless there's a behemoth protecting their fleet, you'll be facing 0 Manpower fleets, which you can easily board (actual players might play with this in mind and adapt). Having a single or a few system improvements could allow you enough time to research the tech and build a fleet of boarders in order to take advantage of a siege.

Basically, the attacker has to have a significant battle strength advantage that outperforms the draft option or create it through siege. Without any developments, a handful of invasion ships (maybe 3 or so) are enough to create this effect, allowing for fast invasions. If an invasion lasts long (because your manpower deployment limit is long) the enemey can also destroy more system developments via bombing.

I'd definitively build some against a player, because they will take advantage being able to invade your systems easily. They'll also take advantage of your fleets lacking manpower, either because you're forced to spam ships or because you invade systems.