[mosshadow]

What does destroying systems do in Freespace 2 ? Some of them are pretty obvious but others dont seem to do anything. Also is it just me or do many systems have too many health points in the fact that the hull will fail before the system?

Weapons- I thought destroying this would stop them from shooting but not much changes. I think the beam fire rate might decrease but Its hard to tell
Sensors- No clue
Comms-No clue
Reactor- Most ships dont have it but the ones that do dont do anything when hit
Engines- The only one that is actually noticeable and obvious.

[CT27]

In some campaigns I've played:

Navigation-Destroying this means a ship can still move, it just can't jump out.

[Trivial Psychic]

IIRC, default behavior is, engines destroyed = ship no move (obviously)... weapons destroyed = turrets fire less effectively or frequently.

[Kie99]

Most of them are just for show, they won't do anything unless it's programmed into the mission.  Destroying engines makes a ship move slower and not move at all if they're all destroyed and destroying weapons makes the turrets fire less accurately, as far as I know that's it.  Reactors certainly don't do anything

On your ship it's a bit different, destroying weapons will stop you from shooting at all unless you're on a ship with a turret, engines stop you dead, communications going will stop you from sending any messages bar calling in support, destroying sensors will stop you from targetting anything.  Damage to these also hinders them, your targeting will go dodgy when your sensors are damaged, your weapons won't fire right etc.  I don't think Navigation going does anything by default but I could be wrong on that.

[BirdofPrey]

Most of them don't do anything other than provide something for mission designers to use for objectives and event triggers.

As far as I know, engines, navigation and weapons are the only ones that have a gameplay effect outside of what's been programmed into the mission.

[NGTM-1R]

Navigation-Destroying this means a ship can still move, it just can't jump out.

Nope. Destroying navigation has no ingame effect on its own.

[jr2]

Which means, if you saw this in a mission, it's because the mission scripted it this way.  It's not a property of FreeSpace, just that particular mission is scripted something like "if time elapsed > 123 and is not destroyed subsystem navigation on ship xyz then ship-depart xyz" or something like that (obviously in real SEXPs, not that example).

[karajorma]

Subsystems on fighter craft do have an effect. If you destroy an enemy fighter or bomber's weapons subsystem it won't shoot at you (after about a minute, the game will automatically blow it up in fact). If a friendly fighter has it's comms destroyed it won't be able to send messages to you (it can call support to fix it somehow, no idea how that's supposed to work with no comms!).

Navigation-Destroying this means a ship can still move, it just can't jump out.

Nope. Destroying navigation has no ingame effect on its own.

There was a bug in the code which existed for a probably a year or maybe even more which had exactly that effect though. Ships with no navigation subsystem wouldn't jump out if given ai-orders to jump out but would jump out if given a departure cue (or maybe the other way round). So it is possible that people have experienced that effect without realising it wasn't actually correct behaviour.

[-Norbert-]

Maybe the fighters have some kind of emergency or backup beacon for cases when their comm is down.

[jr2]

Nah, their buddies call it in for them.  You?  You're Alpha One.  See, they're all jealous.  Hotshot can't call for help?  Serves him right, let's see how good he does without support to patch him up. 

[Blue Lion]

I vaguely recall having wingmen stuck in place because their engines were down and them jumping out when I did. I could just be making that up in my head.

[mosshadow]

The fighter systems are a lot more obvious than the capital systems. They are a bit redundant though because damage to them is rare except for the player since they are the only ones who live long enough to notice such damage. 

[-Norbert-]

With the occasional exception like disabling the Dragon to spy on the Shivans in FS1/FSPort.

[Lorric]

The fighter systems are a lot more obvious than the capital systems. They are a bit redundant though because damage to them is rare except for the player since they are the only ones who live long enough to notice such damage. 

This happens more often in Frontlines with the no shields. I wonder if it happens overall more often than we might think, as we would really only notice taking out the engines.

With the occasional exception like disabling the Dragon to spy on the Shivans in FS1/FSPort.

A particular one I remember seeing a few times is that mission with the tag missiles where you have a temporarily invulnerable wingman. I've seen her get disabled a few times and the Shivans just sitting there pumping shots into her but they can't kill her until she's got all her dialogue out and then her invulnerability is lifted.

[Jeff Vader]

I vaguely recall having wingmen stuck in place because their engines were down and them jumping out when I did. I could just be making that up in my head.

I remember playing some campaign once. One mission involved a large-ish battle and after it I had a few wingmen left, but one was so hammered down that his engines, comms and some other systems were destroyed. When I tried to order the ships to leave, he didn't. He just kept floating there. I called the support ship in and hoped it would go and fix the figher. But no. Of course he couldn't use comms to call for support because he didn't have working comms. In the end  I had to leave him there and continue with the campaign. Sad, man. 

[Dragon]

Which means, if you saw this in a mission, it's because the mission scripted it this way.  It's not a property of FreeSpace, just that particular mission is scripted something like "if time elapsed > 123 and is not destroyed subsystem navigation on ship xyz then ship-depart xyz" or something like that (obviously in real SEXPs, not that example).

Actually, it's not done with SEXPs most of the time, I think. There is a setting in AI profiles table that allows navigation subsystem to prevent a ship from jumping out. Larger mods use this.
In vanilla FS, only engines and weapons have a noticeable effect. The latter is actually very useful, since it makes the turrets fire slower, miss more and, most importantly, do not target bombs. Which means that going for the weapons first makes your next bombing runs much less of a chore.

[Mongoose]

I vaguely recall having wingmen stuck in place because their engines were down and them jumping out when I did. I could just be making that up in my head.

I remember playing some campaign once. One mission involved a large-ish battle and after it I had a few wingmen left, but one was so hammered down that his engines, comms and some other systems were destroyed. When I tried to order the ships to leave, he didn't. He just kept floating there. I called the support ship in and hoped it would go and fix the figher. But no. Of course he couldn't use comms to call for support because he didn't have working comms. In the end  I had to leave him there and continue with the campaign. Sad, man. 

Yeah, that always bummed me out a bit too when it happened.  You'd think that the support ship pilot would know enough to go after the entirely-disabled fighter sitting there, instead of saying WELP GUESS WE'RE DONE HERE.

[Mars]

The Vasudan stretch of FS2 always involved a lot of variously disabled fighters for me. AAA beams have a knack at knocking out the Seth's weapons subsystem - a fair number of wing-men go out that way for me every play through.

[AdmiralRalwood]

There is a setting in AI profiles table that allows navigation subsystem to prevent a ship from jumping out.

This one, to be precise.

[niffiwan]

Nah, their buddies call it in for them.  You?  You're Alpha One.  See, they're all jealous.  Hotshot can't call for help?  Serves him right, let's see how good he does without support to patch him up. 

I have this feeling that the player can still call in a support ship with comms down by using the shortcut (CTRL-R?) instead of the comms menu.