Shields

[Krongurke]

Hi folks,

i had some thoughts about force screens and i would like to benefit from your opinions and experiences.

In our campaign we are about to move from the planetary defense vs. the aliens (i'm DMing a campaign based on the 1994 game UFO: Enemy Unknown) to a more wide spread campaign, spanning the solar system and finally outer space within 200-400 light years.

In my campaign, force screens are rather unique and can only be build by using a very exotic crystalline matter, born in a tri-star system that holds a jump node access (in the middle) to subspace in which a dark matter asteroid was momentarily drawn into, resulting in an asteroid that was converted into crystalline subspace matter.

So shields cannot be created in abundance without this special material.

But to the point:

As very large ships will not be present in most battles I planned, I was thinking about how smaller craft like fighters and bombers can still be useful (without using nukes or things like that). By using normal rules, most fighters will not do any damage to SM+10 or larger craft protected by shields.

BUT I had the idea to create ion cannons that do little damage vs. armor but destabilizing damage to shields. A purely anti-shield weapon so to speak.

For that I had the idea of widening the shield specs from shield strength only to shield strength and shield capacity.

For example: a force screen of a larger vessel (SM+10 or more) will not easily collapse even if fired upon by 20 fighters because the damage is low and only 10% will stick while every round the screen will regenerate 10% of its max strength.

BUT if we introduce shield capacity that will be reduced by any kind of damage the shield has to absorb, maybe we could mirror the constant strain by weapons, fired from smaller craft.

I had the idea of setting the shield capacity to 10 times the shield strength but I have no reasonable idea how much of the damage the shield capacity should take (per hit), what recharge ratio the capacity should have etc.

So I would appreciate any ideas and suggestions you may have, also every other system that could be used to reflect what I had in mind.
(Also arguments why i should NOT use any additional rules are appreciated of course :) )

Thank you in advance!

Best regards
Krongurke

[weby]

Alternative way to make small craft useful is to make shield fully ablative but higher value but limit the effective range of smaller beam weapons.

Thus a swarm of fighters can take down the shields if they get close, but to get close they need to go though a possible opposing fighter screen and then face the close in defense weapons.

Thus in a large ship engagement the larger ships would likely shot at each other but due to damage scaling would be slow to take down the shields of opposing ships, but a swarm of fighters can then go in and ablate the shields allowing for the large ship to start doing real damage.

The fighters could then also likely slowly damage the big ship after the shields are gone.

That is the space combat paradigm in my scifi setting.

[kdtipa]

I definitely agree with the ablative shield idea. That's first on my list. And then if you try out the ion weapons thing, maybe they do no real damage to physical objects, but do higher than normal damage to shields... ablating them faster.

Making shields ablative, and easier to take down might seem to make shields less useful, but instead of having a campaign where you either can or cannot damage a target because of a shield, you now have a campaign where shields are meant to buy you time. Big ships will have big shields that take a long time to take down for a single fighter, and in that time, the big ship's offensive ability should handle the single fighter. But against another large ship, and a swarm of fighters... the shield is really just buying time for the big ship to either do more damage or to find a way to escape.

On top of that, large ships are modular. Once a shield is down, I'd have those fighters be useful by targeting specific systems on the large ship. Shoot off turrets. Hit sensor grids. Anything to weaken the big ship.

[Varyon]

Simply slowing down the rate at which shields regenerate would be sufficient, although the idea of rapidly-regenerating shields that have a fixed capacity is a neat one. I'd be tempted to have rapidly-regenerating shields with a slowly-regenerating capacity, but that might work out to be too complex.

To determine what sort of capacity you want your shields to have, come up with a few scenarios and work out what the combat results will likely be, and see what you like and what you don't, then adjust from there.

If you're willing to break away a bit from reality, Strike Suit Zero had an interesting paradigm - all the ships are made with some incredibly resilient armor that shrugs off bullets and the like but will ablate away against energy weapons. The shields were just the opposite, with kinetic impacts stripping them off rapidly but energy weapons being less effective (although energy weapons still worked just fine; it basically worked out to the shields lasting about as long as the armor did if you just stuck with energy weapons), and were set up so that the ship had to avoid hitting anything for a few seconds before the shield would recharge. As a result of this set up, capital ships didn't even bother with shields, and instead had incredibly thick armor, meaning every single shot from a fighter counted for something, but it took a long time to actually kill the target (of course, the player could speed this up by finding and targeting weak points). Particularly with the rarity of the shielding material, it could be worthwhile for you to do something similar.

[Kelly Pedersen]

Another idea to encourage derring-do and stunts with small fighters is to assume that small craft can actually get under a big ship's shield, and do direct damage there. Spaceships tends to assume that force screens roughly conform to the ship's hull, but if you assume they're more classic Star Trek-style "big bubbles", you can assume that a sufficiently small ship can go underneath the shield but still not crash into the bigger ship's hull, and then do much more immediate damage without having to deal with the shield's DR. This can be combined with the ablative suggestions above - if the shield has to be battered down to a certain level before a small craft has a chance of slipping through it rather than just crashing against it.

Offhand, I'd suggest that to do this, the smaller ship has to be 6 or more SMs smaller than the larger one. That means that SM +10 ships (the smallest I really think count as "capital ships") need tiny SM +4 fighters to slip into, and you don't get SM +10 ships being able to slip into a bigger ship's shields until you hit the truly huge SM +16.

[Varyon]

Originally Posted by Kelly Pedersen

Another idea to encourage derring-do and stunts with small fighters is to assume that small craft can actually get under a big ship's shield, and do direct damage there.

I've considered this in the past, but the primary issue with it is that, if fighters can do this, it's hard to justify missiles not being able to do so, which means swarms of missiles will work out much better than death defying fighter stunts... which kind of defeats the purpose.

[Kelly Pedersen]

Originally Posted by Varyon

I've considered this in the past, but the primary issue with it is that, if fighters can do this, it's hard to justify missiles not being able to do so, which means swarms of missiles will work out much better than death defying fighter stunts... which kind of defeats the purpose.

This is true, but I think that's another reason to state that you have to wait for the shields to be battered down more before slipping in. If missiles in the setting are smart enough to loiter around a capital ship, avoiding point defense, while waiting for other ships to take down the shields enough for them to get in, then you're in a setting where you really don't need fighters at all. So, design your setting where that isn't possible, and you'll still have some room for fighters, and cool tricks like this for them to pull off.

[Varyon]

Originally Posted by Kelly Pedersen

This is true, but I think that's another reason to state that you have to wait for the shields to be battered down more before slipping in. If missiles in the setting are smart enough to loiter around a capital ship, avoiding point defense, while waiting for other ships to take down the shields enough for them to get in, then you're in a setting where you really don't need fighters at all. So, design your setting where that isn't possible, and you'll still have some room for fighters, and cool tricks like this for them to pull off.

While it typically won't lead to fighters ducking under shields for strafing runs, that scheme does lend itself to a decent paradigm, provided you have the caveat that the screens are much more affected by energy weapons than impacts - you have starfighters move in and pound away at the shield enough the missiles can slip through, then either they launch their own small payload of missiles or you have dedicated bombers come in to launch a much larger payload and destroy the target. Meanwhile the starfighters are busy taking on the enemy's starfighters while going after the enemy's bombers or protecting their own. Make the lowering of shields somewhat unpredictable (have it roll a check penalized by the damage it's taken every so often, or at certain damage thresholds) and typically short-lived (shield regenerates rapidly while lowered, coming back up fully once it's full or passes a check or whatever) and you've got an excuse to keep the bombers close while not having a reliable option of just launching missiles from forever-and-a-day away and counting on the shields being down when they arrive. I like that idea enough I might steal it for my own space opera setting, thanks.

[Humabout]

Its worth noting that if your ships mount any ohysical armor, two systems of SotA armor will generally be sufficient to stop SotA energy weapons of 3 to 4 SMs smaller. No amount of shield ablation would help in this case. Ways around this include making all armor ablative, too, or unsurprisingly, don't give ships 2 systems of SotA physical armor. Just be aware that this artifact can happen.

[Varyon]

Originally Posted by Humabout

Its worth noting that if your ships mount any ohysical armor, two systems of SotA armor will generally be sufficient to stop SotA energy weapons of 3 to 4 SMs smaller. No amount of shield ablation would help in this case. Ways around this include making all armor ablative, too, or unsurprisingly, don't give ships 2 systems of SotA physical armor. Just be aware that this artifact can happen.

They need to be unstreamlined (which is indeed appropriate for capital ships) and have 2 systems in each hull section dedicated to armor, which is pretty substantial (30% of the ship's mass is in armor*). And doing this doesn't protect them from the fighters aiming at weakpoints (at -10 to hit, true, but the bonus from the capital ship's SM offsets this markedly) - you need 4 armor sections (60% of the ship's mass is in armor, at which point it's dense enough that it's targeted at -1) to protect from that. Well, under Spaceships 1 rules anyway - needed armor modules is reduced if using the more realistic armor volume rules from Pyramid #3/34. Regardless, you're talking about some very heavily armored ships. If using the optional rules for exposed radiators, those can't be protected by armor (at least, not while exposed), so the fighters can take those out, forcing the target to basically shut down in 30 minutes - a solid mission kill that can set it up for proper destruction (either by heavies or a boarding party, depending on the feel you're going for).

All that said, that's a pretty good observation, and something to keep in mind if you want primarily energy weapons.


*For reference, a Main Battle Tank built using Spaceships would likely have somewhere around 60% of its mass in armor.