The table here, right? (link repost so that you don't have to look in the previous pages for it)
I went for percentile here because it's commonly what shows up in science fiction regarding shields being damaged. It also seemed to be a more genial way of tackling my saying that barrier shielding don't handle damage as location specific as striking directly on target, so they can soak on 2 potentially lethal hits.
Say I'm having a Plumeria shot by another doing a fly-by with the
Type 31 Dual-Cannon turrets. If one shot connects, since the weapon is 2 steps down from what it's shooting at, the shielding might be reduced by 12% (or 10, 15, whichever suits the GM's fancy at the time). If both shots connect (on the weapon's page, we see that it's dual-barreled - the DR sytem doesn't take into account rate-of-fire or multiple uses, only what each use does) then the barrier there would've been reduced by roughly 25% because of those two combined shots.
If the Plumeria is caught barrierless, then those shots would have likely damaged the armor without immediately breaching it. The armor was scorched, torn at, ablated or somesuch and it left scars. Firing subsequent shots at that
very same location with that weapon might savage it further and the hull would threaten to buckle. It might on the same hit at that exact same place... or might not if subsequent shots end up striking different areas of the ship because it's pilot made a roll to expose armor in better condition.
What a potentially lethal weapon does is be able to incapacitate/kill the target in a single use. For a man, a pistol or a knife serves - the knife can breach the skin and reach important organs, if those are the brain or the heart, then they can result in death. It's about the same for a barrierless M6 Daisy armor hit by a focused beam from an aether-saber rifle, and whatever was behind it locally could be charred beyond recognition. For our previous Plumeria target: a
Positron Railgun is the exact same tier, so, the implication is that in a single use, it'd be capable of breaching the hull and striking at a vital component like the engineering housed aether generators, the bridge, the main computer, or perhaps anti-matter ammunition storage. Historically, in the YSS Sakura plot, that happened. An unshielded Sakura-class gunship was struck by a positron railgun and was instantly destroyed (some catastrophic generator failure, probably).
If the shot hits (or was aiming at) the sublight engines, then the outer covering was breached and you're looking at significant damage there too. Or it could be a flesh wound where the attack just explodes a cargo bay open. But it's not the article's job to tell you where you'll hit; that's for your GM's narrative to pick that up.
The objective once you're in the know is that I'm hoping that when you're at the tactical seat of a Plumeria chasing down an NMX destroyer than you know your positron cannons are really effective weapons against it. That your "Medium Anti-Starship Positron Railgun" is suitable against a "Medium-sized Starship" and that with one well-placed shot, once you get through its shields, you can kill it. As for your heavy anti-mecha turrets, well, you'd quickly realize they're not quite at the 'medium-sized ship' level, but they should still be able to damage it and eventually take it down. As for your Heavy Anti-starship torpedoes, those pack a huge punch; they're your ticket into savaging that destroyer big-time, or could be your chance at giving significant hurt to bigger cruisers.
'Purpose' is kind of fluff in most weapon article, but here, we'd use it to define that. Then the rest of the weapon description lets you know the detail of the weapon from range, to rate of fire, to area of effect. In the above-linked positron railgun article, we see the purpose which is anti-starship, and then "damage 4". Which is not greatly evocative to someone new to the site that's not in the know. But if he sees it's an "Medium Anti-Starship" weapon without the damage bit, he can deduce that it's going to be a fairly good weapon against mid-sized starships. Probably more on smaller units, and less on bigger ones.
Personnel and Power Armor fall in the same spot of "there's a person behind the protection", while vehicles and starships fall in another. My plan is to give you something like two table-equivalents of examples to see how each fares.