Alternative Ship Combat Rules
These are lifted from a post (with
notable edits) by barnest2 on CS|RPG, plus some additions by Prestar. (Italics commentary is a combination of Kyris and Prestar.)
Ship Combat, Clarified
1) Ship Life Points
A Spacecraft Scale Ships' Life Points are now calculated as Str+Vit+Wil multiplied by their Wound Armour. This gives Galactica a final LP total of 192. Planecraft Scale vehicles/strikecraft are calculated as straight Str+Vit+Wil.
This rule edit came mainly because I discovered how damn delicate ships are in ship to ship combat under the Cortex rules. This is especially true when you are firing multiple batteries at a single target, which is hardly unusual for any ship but the very smallest. It also gives a much larger range of LP values, giving ships a real difference in vulnerability. For vehicles (especially strikecraft like Vipers, Raptors, and Raiders), this cover the fact that they could be hit by hostile weapons fire and still fly, but any prolonged source of damage (such as you see in the series, when the Viper pilots are putting 3-second-long bursts into Raiders or Raiders are returning the 'favor') and they tend to blow up.
2) Ships and Critical Damage
When a Spacecraft reaches Half of its Life Points or 60 LPs remaining, whichever is Less, it can begin to suffer Critical Damage. Each time a ship takes damage after it has dropped below this mark, roll a D10 and add the Weapon Damage. Compare this result to the Battle Damage Table (on page 270 of the Colonial Warbook IIe), and then apply the effects listed.
Example: Galactica reaches only 59 LPs due to its continued engagement with a pair of Basetars. It is then hit with an attack that does 8 damage after Armour is applied. The GM rolls a d10, resulting in a 7, adds the 8, then looks at the table. Under 15 s/he finds the "Weapons Damaged" Trait. He determines that Galactica's main battery (its Capital Railgun Turrets) are damaged, and cannot be used until they are repaired. (Or frantically jury-rigged by PCs.)
3) Weapons Barrages/Linking Weapons (Thanks to Limerickot I think.)
Identical ship's weapons can be combined in batteries of between two and six. These can be fired as one weapon at a single target. Each weapon after the first gives a +1 to the attack roll, to a maximum of +5 (note that is not die-steps). A successful attack by a battery gives the weapon a +1 Die Step in damage. For example, F.S. Daring combines six of its railguns into a single battery. They get a +5 to hit, and do a damage of D12+D2.
This rule edit was because of the ridiculous number of weapons each ship mounts, and not wanting to be rolling twenty attacks per ship every turn. This is not one of mine, but I'm putting it here because it has an affect on later rulings.
This means that Viper Mark VII's with their three cannon, get a +2 to the attack roll and a +1 Die step in Damage.
4) Point Defence Systems
All Colonial Fleet ships (and certain civilian vessels) mount batteries/networks/arrays of specialized weaponry (usually smaller-bore, rapid-firing--often "Vulcan"-style--guns; rapidly-reloading arrays of small, fast, accurate missiles have been used, though) for shooting down incoming missiles and hostile small craft. Electronic Counter-Measures (jamming, decoys, flares, chaff, et cetera) also uses these rules, but effect missiles only. The Cylons seem to believe physical Point Defense is something that happens for other people. (And The "flak barrage" of a Battlestar (but not any lesser vessel) also degrades incoming direct fire to a degree. to them.)
When a missile barrage enters the range of the Point Defense System(s), the GM/Tactical Officer/Defense Officer should roll the Point Defences' Die-rating. This gives the percentage of missiles destroyed by the Point Defence System(s). The rest of the missiles continue to advance one Range-rating closer, or, if they are at Skirmish-range, impact. Against small craft, the Die should be rolled every turn those small craft stay within the range of a ship's PD system(s). They are not destroyed immediately and instead take damage equal to the PD Systems' Die. Ships with (a) Point Defense System(s) with Capital-range (or--theoretically--greater) can attempt to intercept all missiles passing within its PD range (even if they are not aimed at that ship); this is called "Area Defense" and incurs a two Die-step penalty to the Point Defense Die-rating. (Which is why, normally, only Battlestars do this; not to mention, few other Colonial ships besides a Battlestar even have a Capital-range PDS. Of course, Battlestars also have plenty of main gun batteries to thicken up their Point Defense. And strikecraft. And "Wild Weasel" Raptors.)
Point Defense is also degraded ( minus 1 Die-step) versus missiles only for each additional vessel launching missiles that are being engaged by a given vessel's PD System(s).
A Point defence network may be enhanced by the ships main batteries firing explosive or flak rounds. This enhancement comes at a Addendum: +1 Die-step bonus per battery of direct-fire weapons (usually railguns) added to the defence. When a Battlestar does this, it subtract 1 Die-step from incoming direct-fire weapons (usually railguns) per battery added to Point Defense. All that "flak" would prematurely detonate explosive shells and impart enough energy to some incoming solid shells to casue them to miss. It should also be noted that "flak barrages", unlike normal Point Defense, do not distinguish between firendly and hostile strikcraft/weapons fire; all strikecraft and weapons fire caught "in the solution" of a "flak barrage" are subject to damage/destruction equally.
Example 1: A swarm of 6 missiles heads for F.S. Daring. The gunnery officer rolls the PD network's die (D8) and gets a 6. 60% of the incoming missiles are destroyed, leaving 2 to impact the ships hull.
Example 2: The Tactical Officer aboard F.S. Daring decides there are too many incoming missiles for the standard PD system to handle, and so adds the two main batteries to it. This turns the Daring's PD network from a D8 system into a D12 system.
Example 3: Galatica, covering the civilian ships Jumping out of Ragnar Anchorage, places itself between the Basestars and the Jumping civilian ships. Commander Adama, knowing that those civilian vessels will be turned inside out by the heavy barrage of missiles likely to come from the modern Basestars, orders all a "full flak barrage" (all main gun Batteries that bear added to Point Pefense) and the PDS set to "Area Defense". (Because Adama in the show faced Galactica's dorsal side to the Basestars, literally "covering" the civilian vessels' Jump point with the Battlestar, only two 4-gun batteries--the eight railguns mounted dorsally--bore on the incoming fire. Because I'm ignoring such things in the intrests of both the party and not giving myself headaches, here BS 75 uses all 6 batteries to thicken her point defenses. The Cylons should feel lucky they weren't facing the pre-refit Galactica with her frakking 52 railguns, or 13 batteries.) Galactica thus rolls (d12+d2 minus 2 Die-steps=d10, plus 6 Die-steps=d12+d10) d12+d10 for Area Point Defense. The Cylons, for dog-piling with 4 Basestars, cause a degradation of minus-3 Die-steps to the Point Defense. In the end, Galactica rolls d12+d4, getting a 10 during the first turn of combat. The Cylons' missiles are all destroyed, as are most of their "Sparrows" in the firing solution (since Galactica still rolls d12+d10 vs. strikecraft with her PD). Next round, Galactica's PD system is starting to feel the heat, and she only rolls an 8 on her PD die...thus getting hit by the Cylon missiles. And so on....
Point defence networks... who knows how Margaret Weiss expected those to be handled. This makes it very very simple if you are focusing on the defending ships crew. There are another set of rules in the warbook, which are great if you are focusing on pilots. (Thanks Limerickot)
5) Missile Barrages (and their Damage)
A missile barrage can be badly affected by PD, strikecraft shooting them down, and ECM-strikcraft playing "Wild Weasel"...yet some missiles can still impact. So how do you model the different number of missiles impacting on a ship while still using the Battery rules? If the number of missiles impacting from a single barrage or battery is over 50%, add 1 Die-step to damage. If the number is under 50% but above 1, keep the damage as normal. If the number of missiles impacting is 1, then reduce damage by 1 Die step. If the number of missiles impacting is 0, then 0 damage.
Basic damage is worked out as the Attack Roll vs. the PD roll. This does mean basic damage can work out as zero, but the actual damage should still be rolled.
Example 1: 10% of a 6 missile, D10 damage, barrage is destroyed, leaving 5 missiles to impact on the enemy ship. As this is over 50% remaining, the damage is stepped up to D12.
Example 2: The missiles attack roll was 4, and the PD roll was 8, destroying 80% of the missiles. However, this still leaves 1 of the missiles to impact. It will do no basic damage, but it will do it's normal damage die (though stepped down for their only being 1 impacting).
Missiles are hard. They should work very differently compared to main armaments, but the book does little to show these differences. This is what these rules are for. Also, I don't let ships dodge missiles, or even use innate defence. (Note, subcraft--especially strikecraft--can attempt to dodge missiles. They can also shoot the damn things down.) The only options are ECM and Point Defence... Good luck. (Oh, and your Armor--plus frantic IC prayer--when all else fails.) However, because of missiles' vulnerability to various defensive measures (and because the Colonials learned early in the First Cylon War "There is Never Too Much Point Defense, Just Too Much to Fit on This Ship"), the Colonial survivors of the Cylon Attack have a chance at surviving.
6) Missile Time-to-Impact
Long DRADIS-range: 3 turns to impact
Short DRADIS-range: 2 turn to impacts
Capital-range: 1 turn to impact
Skirmish-range: Immediate impact
Yeah, not much explanation here. There were no rules for this in the book, and given that Long DRADIS-range is supposed to be a couple hundred klicks, I thought these should really appear.
7) Nuclear Warheads
In atmosphere and in the blast radius without hardened shelter..."Game over, man, Game Over!"
When used against a surface target from orbit..."It's the only way to be sure."
Now that I'm done with classic sci-fi movie quotes...
In space, ship-to-ship combat, they are the preferred method of quickly stripping enemy capital ships of their escorts and rapidly destroying hostile capital ships in "Alpha Strikes". Nuclear warheads (in general, but especially tylium-enhanced warheads) cannot be utilized with direct-fire weapons and must be delivered by missiles...making them vulnerable to point defense. Cylons primarily utilize tylium-based kiloton-range "tactical" warheads for both strikecraft and capital missile warheads, only deploying megaton-range "strategic" warheads only for high-priority ground bombardments. The CDF, in comparison, uses fusion warheads of 3-5 Kilotons for strikecraft missiles, 50-100 Kilotons for Escortstar missiles, 100-200 Kilotons on Gunstar missiles, and anything 10 Megaton yield and larger (not usually over 25 MT) to arm Battlestars. Due to the threat of Nukes and abundance of Kiloton-range warheads on both sides, both Battlestars and Basestars are built to "shake off" the effects of being hit by "tactical" nukes.
Nuclear missiles that hit their target ALWAYS do their rolled damage in BOTH STUN and WOUND at SPACECRAFT-scale. Basic damage still applies. Additionally, nuclear missiles with yields in kilotons double their damage total against all targets Except Battlestars and Basestars. Nuclear missiles with yields in the megatons quadruple their damage total against . EVERYTHING
Nuclear weapons are awesomely terrifying and/or horrifyingly inspiring tools, most often used in fiction (understandably) as weapons, and so far only used in real life as will-breaking weapons (twice) and as political tools (quite frequently; there's good reasons why the Galactica first five countries with nukes are the five permanent members of the U.N. Security Council). That "shook off" a "small" nuke (there is only so much Boom! you can stick into a fighter missile, even with Cylon tech) missing most of her armor, coming away with light damage and no radiation hazard...that just presses home how freakishly tough a Battlestar is. But my point is the words "Radiological Alarm" IC should induce serious ass-pucker...and I think these rules do that. Keep in mind: the Basestars and Warstars attacking the Colonies (aside from 4 Basestars on a special mission) are carrying only nukes...and most of the Raiders are also carrying a couple nukes...