FTL Combat

[narcissus]

Are there any rules for FTL combat? I'm guessing the rules are "you can't", but then a follow-up question, which is how do you ambush someone in FTL / make them drop out so that you can fight?

[glitterboy2098]

Fleets of the three galaxies has rules for it. it's pretty difficult and brutal because you have to bring your ship in to within a few dozen feet of the other ship, in order to merge your CG fields. otherwise whatever you shoot will just fall to STL speeds as soon as it leaves your own field and be left far behind you.

as far as ambushing goes, you either attack them somewhere they can't go to FTL (such as near a planet), ambush them when they drop out of FTL and before they can charge back up to return to FTL (and try to disable their drives so they can't), or you ensure that you've had a sabotaur or turncoat on their ship before the ambush that will disable the drives.

[ShadowLogan]

While CG-drives as a form of FTL, it isn't the only form to consider as we know there are:
-Phase Drives
-Rift Jump Drives (essentially travel via Rifts by popping in/out of the Flux Dimension
-Spacegate Jump Systems (Phase technology "teleport" to PW's gates, in theory I suppose something like this could exist elsewhere)
-Space Fold (Invaders DB3, IIRC don't the Arkhons in Rifts proper use a Space Fold drive?)
-Dominators use a Worm-hole drive (DB11 pg48-9)

CG-FTL combat also requires you to match speeds, and that may not be possible as some ships have different FTL rates (A Naruni Audit Ship does 5ly/hr but an Altess Yannar Destroyer can do 8ly/hr, so an Audit ship can't catchup to a Yannar from behind and would likely have to launch from a site in front of the ship).

Combat between ships equipped with the same drive type (aside from CG) might be possible but given their omission in FTL Combat in Fot3G it might indicate you can't under normal circumstances. And then there is the issue of mix-match FTL combat as a CG ship isn't in the Flux Dimension to combat a R-Drive (never mind the Space Fold or Worm-Hole Drives).

Ambushing a CG or Phase Drive ship can be done if you have an Interdictor-class ship to create mobile gravity wells (ex. Araneae-class DB13 pg40-2) which would pull them out of FTL and prevent them from going into FTL. A Dominator Star Fortress might not have sufficient mass to pull this off (if you can fly through a solar system's Ort Cloud and not cut out, I doubt the DSF has sufficient mass). A main sticking point here is the radius of effect is so narrow it seems almost improbable to snatch a ship out. If you don't have access to an Interdictor, then sabotage of the enemy's navigational information might work (remove planet's existence from their charts when plotting their trajectory...).

Alternatively, any FTL is subject to Ambush at their exit point (when the return to real space), IF you know where it is.

[narcissus]

These are good answers. So, a follow up question (relevant to the campaign I'm running)...

If a bunch of Naruni Rapiers attacked a slower ship in FTL - one that's using a CG drive, where the Rapiers are using a Phase drive (so "roughly" equivalent), how would the Rapiers do it? They have belly missiles, but their big guns are forward facing. So do they fly straight at their target until they're within 80', shoot, then try to veer off?
How would this work from a mechanical perspective? I'm assuming big piloting roll penalties to avoid a collision. Any other considerations?

Also, assuming a failed pilot roll, what is impact damage at that speed? To be clear, "that speed" (the differential of 5 light years per hour vs. 5.2 light years per hour) is 326611111.111 miles per second. That's a pretty hefty differential.

[Grazzik]

These are good answers. So, a follow up question (relevant to the campaign I'm running)...

If a bunch of Naruni Rapiers attacked a slower ship in FTL - one that's using a CG drive, where the Rapiers are using a Phase drive (so "roughly" equivalent), how would the Rapiers do it? They have belly missiles, but their big guns are forward facing. So do they fly straight at their target until they're within 80', shoot, then try to veer off?
How would this work from a mechanical perspective? I'm assuming big piloting roll penalties to avoid a collision. Any other considerations?

Also, assuming a failed pilot roll, what is impact damage at that speed? To be clear, "that speed" (the differential of 5 light years per hour vs. 5.2 light years per hour) is 326611111.111 miles per second. That's a pretty hefty differential.

I always assumed you could throttle up or down by having your navi-thingamibob adjust the phase/wave/field/whatever up to a max of the listed FTL speed. That way, you'd do pilot rolls 1) to match/catch up to/approach your target and then 2) boost speed and veer off to avoid counter attack. Almost like an "attack pattern gamma"... perhaps the pilot roll is used to determine the effectiveness of the programmed attack pattern... By throttling up or down, you could have a relative speed as fast or as slow as you want. This would also allow the slower target to pull stunts like a hard brake. See HU2's flying and space maneuvers (pg 86-90) for ideas on how ships could move when at relative speeds when both at FTL. When it comes to weapons, perhaps rather than attacking from the rear of the target, you attack from the front moving backwards so forward pointing guns and missiles actually point to the rear relative to direction of motion. So, missiles would act more like horizontal depth charges or contact mines using propulsion at FTL to move into the target's path rather than towards the target...

[ShadowLogan]

If a bunch of Naruni Rapiers attacked a slower ship in FTL - one that's using a CG drive, where the Rapiers are using a Phase drive (so "roughly" equivalent), how would the Rapiers do it?

Simple answer, they don't. While the GG-Drive and P-Drive operate similarly, the fields they create are not the same. The FTL combat per the text specifically says they merge the CG-fields of the participating vehicles. I don't see how a CG-field could merge with a Phase-field. Now a CG-field could envelope the P-Drive craft if it is small enough and they got close enough, but the craft is Phased preventing it from being attacked (IINM).

Also, assuming a failed pilot roll, what is impact damage at that speed? To be clear, "that speed" (the differential of 5 light years per hour vs. 5.2 light years per hour) is 326611111.111 miles per second. That's a pretty hefty differential.

Given one of the craft is phased and the other isn't, for simplicity I would say nothing.

Now if it hit something else, I'd use the collision damage (RUE pg345, it's also in RMB) for 2d4SDC per 10mph (SoL is 186,000 miles per second, or ~6.7x10^8mph) based on the relative difference in speed between the two objects. So, if it was for example equal to approximately the SoL (for simplicity) you do 2d4x6.7x10^6 MD (or 2d4x10,000,000MD), but if it was only 1,000mph it would be 2d4MD (IINM).