Spaceships/JC: Exo-armors vs a Corvettes Example Combat

So I've decided to start posting combat examples for GURPS Spaceships using the Jovian Chronicles conversions I recently did, more or less in response to a thread on the SJ Games forums asking for turn by turn examples of GURPS Spaceship combat. I started with a bunch of small craft fighting each other, at it worked out pretty well. Now I'm going to try a bunch of small craft fighting an escort ship.

I'm trying to run these examples without any house rules. I'm not doing a perfect job of that, though. One issue is that technically, a single pilot/gunner can't fire two different weapons (GSS1 p53). I don't consider it at all abusive to let the pilot/gunner use both his main weapons and his point defense weapons at the same time, with appropriate multi-tasking penalties, and I didn't notice that rule on my first read through. I'm not about to go back through these examples and add a semi-competent AI gunner, but you can do that mentally if it really bothers you.

Another issue is that multiple identical weapons in a turret mount cannot fire together (GSS1 p57). I didn't notice that rule either. Tripling the number of rolls made for turret attacks is not going to make this example shorter or easier to read and I doubt it would affect the outcome. Again, you can do it mentally if it really bothers you.

Thanks to the eagle-eyed readers of the forum and on the comments below who pointed out my mistakes. It's a learning experience and I welcome the feedback.

Scenario: Sensor Picket Miyu

During the Battle of Elysees, the Bricriu-class Corvette Miyu is on sensor picket duty at the flank of the 4th CEGA fleet. The Miyu comes under a probing attack by a reinforced flight of 4 JAF Pathfinders (enhanced with a Medium Battery Improved VRF Laser point defense turret). The Miyu must drive off her attackers, but the JAF pilots need to destroy the Miyu quickly before CEGA reinforcements arrive.

Special Rules and Command Orders

Objectives: The Jovians want to destroy the Miyu. The Miyu would like to not be destroyed and also would like to not be forced from her patrol area.

The Jovians win if they destroy the Miyu with at least two Pathfinders still able to fight, or if they force the Miyu to retreat without losing any Pathfinders. The Miyu wins by preventing a Jovian victory.

Retreating: Although this is war, there's a limit to how hard either side is willing to fight. Any Pathfinder that is damaged below 0 HP must take a Retreat maneuver (if possible) on its next action and cannot make attacks as long as it is capable of Retreating. The Miyu will not fire on a heavily damaged exo-armor that is Retreating and not firing (or that has a destroyed engine or no fuel left and is not firing as it uncontrollably drifts away). The Jovians must retreat after the 10th turn, so as to not linger in the face of approaching CEGA reinforcements.

The Miyu must fight as long as she has Medium Batteries with ammo operational, but can take a Retreat maneuver if all her Medium Batteries are destroyed or run out of ammo.

Opening Turn: The Miyu is on sensor picket duty and can detect the incoming Jovian flight. Both sides have been making Hold Course maneuvers with +0 acceleration bonuses on the turns before the Jovians come into the Short range of both sides weapons. (Yes, technically the Jovians can launch missiles from outside extreme range, but both sides are well aware that launching a half dozen missiles into the Miyu's PDS is an exercise in futility). Both sides have power allocated to all their energy weapons and are taking Aim and Wait (Point Defense) maneuvers on the turn before the fight starts.

All of the Jovian Pathfinders will act before the Miyu. The Jovians start off in formation but do not have to maintain it.

Turn Length and Scale: None of the ships have less than 0.05G+ of acceleration, more than 10G+ of acceleration, more than 5 mps of delta-V, or many weapons that reach past Short range. The best scale is Close Scale and the best Turn Length is 1-minute per turn.

delta-V reserves: For simplicity, the Pathfinders have 4.5 mps of delta-V. It takes the Pathfinders 1G and 0.3 mps to get a +2 acceleration bonus, 1.5G and 0.5 mps to get a +3 acceleration bonus, 2G and 1.2 mps to get a +4 acceleration bonus, and 3G and 1.8 mps of delta-V to get a +6 acceleration bonus.

The Miyu has 20 mps of delta-V reserves. She can spend 0.2 mps of delta-V at 0.5G to get a +1 acceleration bonus or 1.2 mps of delta-V at 1G to get a +2 acceleration bonus.

The rapid increase in delta-V reflects the doubled fuel consumption for high thrust operations.

Skill Levels and Crew Actions: The Jovians have Pilot-14, Artillery/Gunner (Whatever)-14, and all other space related skills at 13. The numerous and professional CEGA crew of the Miyu have Skill-14 at whatever they're trying to do. The Miyu can perform one of every type of task every turn without multi-tasking penalties, except for Gunnery Tasks, where she can perform 1 Gunnery Task for each of her weapon batteries.

Play of the Encounter

Jovian Turn 1: The Jovians know that if they can get behind the Miyu, her PDS won't be able to intercept their missiles. However, her particle beam and KKC turrets will be able to, if not well. At least when they first come into range, launching missiles is still too high risk. Their particle beams can just barely penetrate the Miyu's armor, so they can try to plink out important systems as they approach. The end goal is to use the plasma lances to cut up the weapon systems and then finish her off with the missiles.

Each Pathfinder chooses to perform 3 tasks this turn, and they'll stay in formation no matter what. They'll perform a Pilot task for a Closing maneuver (preferring to get closer over being advantaged), a Gunnery task to Aim and Attack with the particle-beams, and a Gunnery task to Wait (Point Defense) in hopes of intercepting any KKC fire. There isn't anything they can do about the particle beam fire except for Dodge and hope.

Pathfinder 1 leads off, accelerating at 1.0G with 0.3 mps of delta-V for a +2 acceleration bonus and attempting a Closing maneuver on the Miyu. She rolls a 9 against Pilot-14, -2 for multitasking, +2 for acceleration, +0 for the exo-armor's Handling, and succeeds by 5. The Miyu counters with a roll of 14 against Pilot-14, +1 for acceleration, -1 for the corvette's handling, and gets an MoS of 0 and loses the contest. The lead Pathfinder comes in on Attack vector and drops to Close range against the Miyu's front hull.

She fires her particle-beam, hoping to get lucky and take out the PDS. She has Gunner-14, -2 for multi-tasking, +9 for the target's size, -3 for the beam's sAcc, -1 for the corvette's ECM array (halved for the Pathfinder's tactical array), -4 for close range, and +1 for a gun braced in both robot arms, rolling a 15 vs an effective 14 and missing with all three shots.

Pathfinder 2 follows, accelerating at 1.0G with 0.3 mps of delta-V for a +2 acceleration bonus and attempting a Closing maneuver against the Miyu while staying in formation. He rolls a 13 against Pilot-14, -2 for multitasking, +2 for acceleration, +0 for the exo-armor's Handling,and successfully stays in formation, ending up on Close range attack vector on the Miyu's front hull.

He fires his particle-beam, hoping to get lucky and take out the PDS. He has Gunner-14, -2 for multi-tasking, +9 for the target's size, -3 for the beam's sAcc, -1 for the corvette's ECM array (halved for the Pathfinder's tactical array), -4 for close range, and +1 for a gun braced in both robot arms, rolling a 11 vs an effective 14 and hitting with all three shots. The lumbering corvette attempts to Dodge, starting with a 7 for half the Pilot skill and adding 1 for ECM, rolling a 5 against an 8 and successfully avoiding all three shots.

Pathfinder 3 makes his attack run, accelerating at 1.0G with 0.3 mps of delta-V for a +2 acceleration bonus and attempting a Closing maneuver against the Miyu while staying in formation. He rolls a 4 against Pilot-14, -2 for multitasking, +2 for acceleration, +0 for the exo-armor's Handling,and successfully stays in formation, ending up on Close range attack vector on the Miyu's front hull. A lovely critical success wasted!

He fires his particle-beam, hoping to get lucky and take out the PDS. He has Gunner-14, -2 for multi-tasking, +9 for the target's size, -3 for the beam's sAcc, -1 for the corvette's ECM array (halved for the Pathfinder's tactical array), -4 for close range, and +1 for a gun braced in both robot arms, rolling a 8 vs an effective 14 and hitting with all three shots. The lumbering corvette attempts to Dodge, starting with a 7 for half the Pilot skill and adding 1 for ECM, rolling a 7 against an 8 and successfully avoiding two shots. The third shot hits for 4d bur sur rad (5) d-damage, rolled as 15. The Miyu's hardened 40 dDR reduces the armor divisor to (3) and is effectively reduced to 13 dDR, so 2 d-damage penetrates on system 1, the armor. A Bricriu has 100 dHP, so 2 damage is not more than 10% and doesn't disable or destroy the system, but the Miyu does need to roll its HT of 13 to avoid losing a system to the surge effect: an 11 on the die and the Miyu is safe for now.

Pathfinder 4 makes her attack run, accelerating at 1.0G with 0.3 mps of delta-V for a +2 acceleration bonus and attempting a Closing maneuver against the Miyu while staying in formation. She rolls a 13 against Pilot-14, -2 for multitasking, +2 for acceleration, +0 for the exo-armor's Handling,and successfully stays in formation, ending up on Close range attack vector on the Miyu's front hull.

She fires her particle-beam, hoping to get lucky and take out the PDS. She has Gunner-14, -2 for multi-tasking, +9 for the target's size, -3 for the beam's sAcc, -1 for the corvette's ECM array (halved for the Pathfinder's tactical array), -4 for close range, and +1 for a gun braced in both robot arms, rolling a 12 vs an effective 14 and hitting with all three shots. The lumbering corvette attempts to Dodge, starting with a 7 for half the Pilot skill and adding 1 for ECM, rolling a 7 against an 8 and successfully avoiding two shots. The third shot hits for 4d bur sur rad (5) d-damage, rolled as 12. The Miyu's hardened 40 dDR reduces the armor divisor to (3) and is effectively reduced to 13 dDR, but that's still enough to stop the attack.

CEGA Turn 1: The Miyu is down to 98 dHP, facing a formation of 4 Pathfinders at Close range. Letting them get closer would be bad, as only some lucky maneuvering saved him from more damage in their first wave of attacks, and at closer range they might start firing at his weak points and ripping through his hull. Retreating is an option, but it would put his rear hull to the Pathfinders, and the MMJ-4 missiles are more than sufficient to tear through his ship. He orders Evasive maneuvers while seeing how the Pathfinders fare against his KKCs; for now, he'll hold the particle beams in reserve against missile attacks from any Pathfinders that get behind him.

The captain makes a Command task to perform space tactics against the Jovian formation; he'll go for offensive tactics to predict their defense patterns and reduce their Dodge by 1. He rolls against Tactics-14, +1 for the 1 minute turn, but fails with a 16. Meanwhile, the navigator performs a Navigation task for Tactial navigation, rolling against Navigation (Space)-14 and easily succeeding with a 7. The pilot will get +1 on a Pilot rolls for the next turn. The pilot, in turn, makes evasive maneuvers, spending 0.5G of thrust and 0.2 mps of delta-V to get a +1 acceleration bonus that will be doubled this turn, as well as a +1 to dodge. The Miyu is now at close range with her central hull facing the Pathfinders.

Then the KKC gunners open up, each battery firing a combined salvo of 9 shots against the first two Pathfinders. The port battery starts, rolling a 10 against Artillery-14, +5 for target SM, -6 for the KKC's sAcc, -3 for the 2 mps gun velocity, -2 for ECM, +2 for the RoF bonus for 9 shots, and +4 for proximity fusing. He succeeds by 4, and hits with two shots (the guns have Rcl 4). Pathfinder 1 fires 200 laser PDS shots at it, rolling a 6 against Gunnery-14, -1 for target SM, +0 for range, +8 for RoF 200, -2 for multitasking, and succeeds by 13, easily obliterating the gun rounds. The starbard battery fires at Pathfinder 2, rolling a 12 against Artillery-14, +5 for target SM, -6 for the KKC's sAcc, -3 for the 2 mps gun velocity, -2 for ECM, +2 for the RoF bonus for 9 shots, and +4 for proximity fusing. He succeeds by 1, and hits with a single shot, which is obliterating by another 200 PDS lasers (rolled a 9 versus a target of 18).

The captain resolves to reverse his targeting next turn, holding the KKCs for point defense while the p-beams sweep the Jovians from the stars.

Jovian Turn 2: The Jovians still need to get behind the Miyu, preferably at point-blank range.

Each Pathfinder chooses to perform 3 tasks this turn, and they'll stay in formation no matter what. They'll perform a Pilot task for a Closing maneuver (preferring to get closer over being advantaged), a Gunnery task to Aim and Attack with the particle-beams, and a Gunnery task to Wait (Point Defense) to keep intercepting any KKC fire.

Pathfinder 1 leads off, accelerating at 1.0G with 0.3 mps of delta-V for a +2 acceleration bonus and attempting a Closing maneuver on the Miyu. She rolls a 10 against Pilot-14, -2 for multitasking, +2 for acceleration, +0 for the exo-armor's Handling, and succeeds by 4. The Miyu counters with a roll of 8 against Pilot-14, +2 for evasive acceleration, -1 for the corvette's handling, +1 for tactical navigation, and gets an MoS of 8 and easily wins the contest. The lead Pathfinder falls off the Attack vector and moves to Short range against the Miyu's center hull.

Long range particle beam fire is unlikely to hit in general and won't penetrate the corvette's armor. The Jovians hold their fire and their formation.

CEGA Turn 2: The Miyu has plenty of reaction reserves and reinforcements inbound. Long range particle beam fire is unlikely to hit nimble exo-armors, but it may keep the Jovians back and it doesn't cost the captain anything. He'll continue with his evasive maneuvers and tactical analysis.

The captain makes a Command task to perform space tactics against the Jovian formation; he'll go for offensive tactics to predict their defense patterns and reduce their Dodge by 1. He rolls against Tactics-14, +1 for the 1 minute turn, and barely succeeds with a 15. Meanwhile, the navigator performs a Navigation task for Tactial navigation, rolling against Navigation (Space)-14 and easily succeeding with a 10. The pilot will get +1 on a Pilot rolls for the next turn. The pilot, in turn, makes evasive maneuvers, spending 0.5G of thrust and 0.2 mps of delta-V to get a +1 acceleration bonus that will be doubled this turn, as well as a +1 to dodge. The Miyu is still at short range with her central hull facing the Pathfinders.

Then the particle beam gunners open up, each battery firing a combined salvo of 9 shots against the first two Pathfinders. The port battery starts, rolling a 6 against Gunner-14, +5 for target SM, -8 for Short range, -3 for the beam's sAcc, -2 for ECM, and +2 for the RoF bonus for 9 shots. He succeeds by 2, and hits with three shots (the beams have Rcl 1). Pathfinder 1 desperately dodges, rolling an 11 against a base of 7 with a +1 for the lone ECM system, a -1 for the Miyu's command task, and failing miserable. The 300 MJ particle beams do 5dx3 d-damage each, for 52, 46, and 53 damage. Hardened dDR 21 armor is effectively dDR7 against the p-beams, and a total of 130 d-damage penetrates. The Pathfinder is dropped to -110 dDR, more than -5xdHP, and is immediately destroyed.

The starboard battery contiues, rolling a 10 against Gunner-14, +5 for target SM, -8 for Short range, -3 for the beam's sAcc, -2 for ECM, and +2 for the RoF bonus for 9 shots. He misses by 2, and Pathfinder 2's pilots sighs with relief.

Jovian Turn 3: The new flight leader in Pathfinder 2 is no longer interested in slowly moving behind the Miyu. He wants to get behind the corvette, pop off his missiles, and get the heck out of the area before getting roasted by more particle beams.

Pathfinder 2 barrels in, accelerating at 3.0G with 1.8 mps of delta-V for a +6 acceleration bonus and attempting a Closing maneuver on the Miyu. She rolls a 7 against Pilot-14, -2 for multitasking, +6 for acceleration, +0 for the exo-armor's Handling, and succeeds by 11. The Miyu counters with a roll of 6 against Pilot-14, +2 for evasive acceleration, -1 for the corvette's handling, +1 for tactical navigation, and gets an MoS of 10 and barely loses the contest. The Pathfinder formation aligns off the Miyu's rear hull at Short range.

In sequence, each Pathfinder fires off both MMJ-4 16 cm missiles. Pathfinder 2 starts by rolling a 12 against Artillery-14, +9 for target SM, +2 for missile sAcc, -3 for more than 1 mps but less than 3 mps of relative velocity (per the errata, the missiles are travelling at 2 mps, same as the guns), -1 for the target's ECM, -2 for multi-tasking, and no bonus or penalty for rate of fire: net is a 19, and both missiles hit easily. The KKC gunners respond with the entire port battery, rolling a 12 against Artillery-14, -1 for target SM, -6 for the KKC's sAcc, -3 for relattive velocity, +2 for RoF, and misses entirely against a target of 6. The Miyu then dodges, rolling a 14 against a base 7, -1 for handling, +1 for ECM, and +1 for evasive, and misses by 6. Both missiles impact the rear hull for 6dx4 d-damage, doing 82 and 76 to hull locations 1 and 3. The hardened armor nullifies the missile's penetrators and absorbs 40d-damage, allowing 42 and 36 d-damage to get through. Neither attack is enough to destroy the target system, but both systems are disabled, leaving the Miyu a drifting derelict without an engine.

Clearly, the Pathfinders should have used proximity fused missiles here, as another 5-10 missile hits in each volley would have finished the Miyu off. I resisted, because in my head I'm downgrading proximity fused missiles to RoF x10, d-Dmg/3, and they wouldn't have penetrated the Miyu's armor at all that way. Which would have been more cool.

Pathfinder 3 follows with more missiles, rolling a 10 against Artillery-14, +9 for target SM, +2 for missile sAcc, -3 for more than 1 mps but less than 3 mps of relative velocity (per the errata, the missiles are travelling at 2 mps, same as the guns), -1 for the target's ECM, -2 for multi-tasking, and no bonus or penalty for rate of fire: net is a 19, and both missiles hit easily. The KKC gunners respond with the entire starboard battery, rolling a 12 against Artillery-14, -1 for target SM, -6 for the KKC's sAcc, -3 for relattive velocity, +2 for RoF, and misses entirely against a target of 6. The Miyu then dodges, rolling a 13 against a base 7, -1 for handling, +1 for ECM, and +1 for evasive, and misses by 5. Again, both missiles impact the rear hull for 6dx4 d-damage, doing 100 and 83 to hull locations 1 and 2. The hardened armor nullifies the missile's penetrators and absorbs 40d-damage, allowing 60 and 43 d-damage to get through. The first missile destroys armor location 1 and disables the engine room in location 6; the second missile disables armor location 2. The Miyu is at -81 dHP, but is still holding together.

Pathfinder 4 tries to finish the corvette off with the last missiles, rolling a 9 against Artillery-14, +9 for target SM, +2 for missile sAcc, -3 for more than 1 mps but less than 3 mps of relative velocity (per the errata, the missiles are travelling at 2 mps, same as the guns), -1 for the target's ECM, -2 for multi-tasking, and no bonus or penalty for rate of fire: net is a 19, and both missiles hit easily. No point defense is possible, so the Miyu dodges, rolling a 9 against a base 7, -1 for handling, +1 for ECM, and +1 for evasive, and misses by 1. Again, both missiles impact the rear hull for 6dx4 d-damage, doing 79 and 94 to hull locations 6 twice. The hardened armor nullifies the missile's penetrators and absorbs 40d-damage, allowing 39 and 54 d-damage to get through. The first missile destroys the already damaged engine room; the second missile destroys armor location 2 and passes another disable result to the engine room, destroying it. The Miyu is at -174 dHP, and rolls HT to survive: a 12 is barely enough.

CEGA Turn 3: The Miyu is wrecked but still has attitude controls; she is drifting controllably and can hopefully still avenge herself. Point defense is irrelevant now that the Pathfinders have dumped all their missiles and dodging is impossible. She'll turn to face her tormentors and attempt to pick them off.

The captain makes a Command task to perform space tactics against the Jovian formation; he'll go for offensive tactics to predict their defense patterns and reduce their Dodge by 1. He rolls against Tactics-14, +1 for the 1 minute turn, and barely succeeds with a 13. The pilot makes a controlled drift maneuver to turn the front of the ship toward the enemy. The Miyu is still at short range with her central hull facing the Pathfinders.

Then the particle beam gunners open up, each battery firing a combined salvo of 9 shots against the first two Pathfinders. The port battery starts, rolling a 10 against Gunner-14, +5 for target SM, -8 for Short range, -3 for the beam's sAcc, -2 for ECM, and +2 for the RoF bonus for 9 shots. He fails by 2, and misses. The starboard battery continues, rolling a 14 against Gunner-14, +5 for target SM, -8 for Short range, -3 for the beam's sAcc, -2 for ECM, and +2 for the RoF bonus for 9 shots. He fails by 6, and also misses.

The port KKC battery fires, rolling a 5 against Artillery-14, +5 for target SM, -6 for the KKC's sAcc, -3 for the 2 mps gun velocity, -2 for ECM, +2 for the RoF bonus for 9 shots, and +4 for proximity fusing. He succeeds by 9, and hits with three shots (the guns have Rcl 4). Pathfinder 2 fires 200 laser PDS shots at it, rolling a 7 against Gunnery-14, -1 for target SM, +0 for range, +8 for RoF 200, -2 for multitasking, and succeeds by 12, easily obliterating the gun rounds. The starbard KKC battery fires at Pathfinder 2, rolling against Artillery-14, +5 for target SM, -6 for the KKC's sAcc, -3 for the 2 mps gun velocity, -2 for ECM, +2 for the RoF bonus for 9 shots, and +4 for proximity fusing. He succeeds by 3 with an 11, and hits with a single shot, which is obliterating by another 200 PDS lasers (rolled a 13 versus a target of 18).

Jovian Turn 4: The Jovians have won a significant victory, as the drifting Miyu can no longer interfere with Jovian exos and ships attempting to move through this path in space. The Jovians quickly disengage to long range and head into towards the rest of the CEGA fleet, signalling for their own reinforcements.

Conclusions

Apparently, I can't design ships. Swapping the Bricriu's e-mag guns with her habitat and PDS system would have been sufficient to give the corvette all-angle protection against missiles. Then she could have used her e-mag guns and particle beams to destroy the Pathfinders no matter where they were.

That said, this was an interesting little scenario. The increased crew actions on the Bricriu added a bit to it, and there was some potential for some interesting tactics. Too bad that Spaceships is so overwhelming realistic that there aren't many good switches to allow cinematic dogfights.

The love affair with missiles is probably realistic, but it's annoying: missiles can fire from a destroyed craft (beams and guns can't); missiles don't take targeting penalties for a badly damaged ship (beams and guns do); missiles do more damage than beams and are much more accurate at lower Rcl than guns... missiles just rock. The perfect ship has a lot of missile launchers, ECM, and improved VRF laser point defense arrays, and minimal armor because proximity fuse missiles are either stopped by point defense or destroy the ship. Which is realistic, I guess, but it's not Jovian Chronicles.

I'm going to a fight off a trio of Bricriu's against a Valiant, just to do a capital on capital ship fight. And then I'm going to start thinking about some house rules to address the issues I currently have:

1. Missiles are too effective, especially with proximity fuses.
2. KKCs and E-mag guns are too ineffective. If nothing else, e-gun rounds should be much harder to intercept.
3. It needs to be easier to rendezvous with a craft and harder to shake rendezvous attempts.