Any planetary scale weapon will still devastate them, especially one with Blast since they're going to be packed rather tightly together
If that planetary scale weapon does 35+ dmg then yes their 20 dmg reduction wont do much against that, but if they miss with an energy based weapon...
"sir we just fired our big ass laser at the group of rebels are you sure that was the best coarse of action?"
"Of course if anything it was a merciful and swift death"
"Um sir that big ass laser we just fired is coming back right at us"
"..."
PS the more you have with this build the better
If it's a planetary sized weapon like the Death Star it wouldn't be 35+ damage to characters. It would be 100 times that, so the damage is 3500 and no matter what the group would be vaporized. Now that 20 points reflected back to say the Death Star would be 100 times less damaging due to difference in weapon scale. It ultimately becomes .02 damage and the Death Star shrugs it off.
Using capital ship weapons it would be times 10 instead of 100, so the Jedi characters take 350 points of damage. They reflect a whopping 2 points of damage that is easily absorbed by the ship. Isn't weapon scale fun?
Im pretty sure the weapon scale stays the same since its still the same shot unless there's some ruling about reflect I havent read. Still it makes no sense if you fire a big ass shot it some how shrinks when it gets reflected back by someone smaller
PS to be fair if the GM is using that to take down PCs (with no ship) then he's an ass
Page 230 of F&D in the box titled Starships, Vehicles, and Scale, "When dealing with a vessel’s weapons, armor, and hull trauma threshold, every point is equal to 10 points of the equivalent characteristic in personal scale. For example, a laser cannon with a base damage of 3, mounted to a starfighter, deals 3 points of damage when fired at another spacecraft, but 30 points of damage when fired at a human. Conversely, a human-sized blaster rifle would need to deal 10 points of damage to a starship to inflict even 1 point of damage on it."
I followed the logic for starship weapons being 10 times more damage to a person on personal scale when it came to planetary scale weapons. A planetary scale weapon would deal 100 times the amount of damage compared to a personal scale weapon. Like I said in my example, the reflected damage is miniscule and absorbed easily while the party ends up dying due to massive damage.
You do realize that planetary scale is "vehicle" scale, right? There are only two levels - personal and planetary.