Very Rapid Fire

[JazzJedi]

GURPS Powers has a Very Rapid Fire modifier that is a little vague on details as that what weapons or attacks could possibly qualify for it. "Fire your full RoF almost instantly" is not helpful, since it could be RoF 10, but a weapon with RoF 100 fires 10 shots in 0.1 seconds. If that is not "almost instantly" then I don't understand this modifier.

So what do you all think of the following tweak: Weapons with RoF 25+ are classified as Very Rapid Fire. They get two extra hits per full multiple of Recoil by which you make your attack roll. At RoF 50+, its three extra hits. At RoF 100+, its four extra hits, and so forth.

[Aldric]

I don't think it has anything to do the numbers of projectiles fired, just that they're fired so fast that there is almost no recoil.

[Kromm]

Very Rapid Fire (VRF) is about the rate of fire occurring faster than recoil is felt – or recuperation being fast enough to keep up with rate of fire. Thus, it's really about Rcl, not RoF.

First, realize that VRF is an attack modifier, meaning that it's for Affliction, Binding, or Innate Attack, or an advantage that's also modified with Ranged. All of those things have Rcl 1. Very Rapid Fire explicitly forbids Extra Recoil, which means it's only ever possible for these Rcl 1 attacks. What it does, in effect, is reduce Rcl 1 to "Rcl ½" and impose a few related special effects.

Second, note that VRF requires some level of Rapid Fire. But that could be any level, from RoF 2 on up (though it's only really useful at RoF 3+).

A good example of a low-RoF attack with VRF would be a high-tech pepperbox machined finely enough that it truly fires, say, seven barrels at once – literally, meaning that recoil arrives all at once, after all the barrels have discharged. This would have Rapid Fire, RoF 7, VRF, +80%. The attack would have RoF 7 and an effective Rcl ½. If you succeeded by three on an attack roll, you'd hit with all seven shots. You couldn't spread this fire or suppress with it because it's just seven shots down a single line of fire . . . but it wouldn't require crazy-high RoF, either.

[Varyon]

GURPS is very much a "get what you pay for" system, so Very Rapid Fire would have the same effect (functionally Rcl 0.5) regardless of if you have RoF 3, 30, or 3,000,000. The diminishing returns of high RoF (in terms of % of rounds that hit with a given roll) is simply a function of how RoF works in GURPS; if you intend to fix it for VRF, you'll want to fix it for normal RF as well.
EDIT: Ninja'd by Kromm

[Fred Brackin]

Originally Posted by Aldric

I don't think it has anything to do the numbers of projectiles fired, just that they're fired so fast that there is almost no recoil.

Yes, it's a matter of how the weapon gets designed (either in Real World or game terms).

Real world weapons that have had this characteristic like the G-11 or the Kriss Super V have fired in extremely short bursts (3 or even 2 rounds/burst) but have had the intention that you get multiple hits ona single target from those bursts. They can't be spread among multiple targets though.

Weapons with super high ROFs like electric gatlings don't have the concentrated fire like the Powers mechanic does. Fire your MG134 out of the side of your helicopter and you've got a super lead hose you can sweep over the whole available arc.

Then there's the other sense of "designed" which is the meta-game/Powers one. In that sense any weapon designed with Powers that has this modifier folows the rules in Powers regardless of its' "sustained" ROF .

[JazzJedi]

Originally Posted by Kromm

Very Rapid Fire (VRF) is about the rate of fire occurring faster than recoil is felt – or recuperation being fast enough to keep up with rate of fire. Thus, it's really about Rcl, not RoF.

First, realize that VRF is an attack modifier, meaning that it's for Affliction, Binding, or Innate Attack, or an advantage that's also modified with Ranged. All of those things have Rcl 1. Very Rapid Fire explicitly forbids Extra Recoil, which means it's only ever possible for these Rcl 1 attacks. What it does, in effect, is reduce Rcl 1 to "Rcl ½" and impose a few related special effects.

Second, note that VRF requires some level of Rapid Fire. But that could be any level, from RoF 2 on up (though it's only really useful at RoF 3+).

A good example of a low-RoF attack with VRF would be a high-tech pepperbox machined finely enough that it truly fires, say, seven barrels at once – literally, meaning that recoil arrives all at once, after all the barrels have discharged. This would have Rapid Fire, RoF 7, VRF, +80%. The attack would have RoF 7 and an effective Rcl ½. If you succeeded by three on an attack roll, you'd hit with all seven shots. You couldn't spread this fire or suppress with it because it's just seven shots down a single line of fire . . . but it wouldn't require crazy-high RoF, either.

That's very helpful, thanks! Wouldn't this be a good modifier for beam weapons?

[RedMattis]

Originally Posted by JazzJedi

That's very helpful, thanks! Wouldn't this be a good modifier for beam weapons?

Depends on how deadly you want the beam weapons to be. Increasing the number of hits you get in on someone generally makes armor more important and squishy (low/no DR) targets die faster.

[Kromm]

Originally Posted by JazzJedi

That's very helpful, thanks! Wouldn't this be a good modifier for beam weapons?

It would certainly be possible for beam weapons, and most likely easier given their lack of recoil. Whether you'd actually do so would be a question of design. My money would be on "no."

The reason is this: It's surprisingly useless to be able to plug a single target with lots of small holes.

Most realistic weapons are designed for single-hit effectiveness against their intended targets; e.g., any hit by a GPMG will incapacitate a human, and any hit by a 20mm CIWS will neutralize an incoming missile. High rate of fire serves to (1) increase the odds of getting that one hit by putting more shots in the air (that's the bonus to hit under Rapid Fire, p. B373, which you get with or without VRF) and/or (2) engage multiple targets (Spraying Fire and Suppression Fire, pp. B409-410, which you lose with VRF).

While gamers are enamored of the idea of plugging their targets lots of times for massive injury, that's really only effective against huge-but-soft targets, as when spraying elephants with AK-47s. Real-life situations mostly involve hard targets, where whether you hit one time or 100, the shots will bounce off if they can't penetrate. The engineering to handle high rates of fire is usually better put toward hotter shots in those cases; e.g., instead of loading up 300+ lbs. of Minigun and ammo to bounce 7d pi off a DR 50 APC hull 66 times, you're better off loading up 300+ lbs. of Chain Gun and ammo to pelt that DR 50 with just three rounds of 6d×4 pi++ and an explosive follow-up.

This goes for beam weapons, too. You'll normally want either to shoot lots to get one hit on an incoming missile or to engage lots targets (in which case VRF isn't going to help), or to bore a single, deep hole in a target (in which case the cost of VRF would be better put toward increasing basic damage). I suppose there might be weirdos who need to shoot dinosaurs lots with lasers, but to be kind, that's . . . unusual. (And to follow-up: The Third Edition idea of cumulative damage from multiple hits in the same place was bad science – it doesn't work that way.)

[Varyon]

Originally Posted by Kromm

It would certainly be possible for beam weapons, and most likely easier given their lack of recoil. Whether you'd actually do so would be a question of design. My money would be on "no."

The reason is this: It's surprisingly useless to be able to plug a single target with lots of small holes.

Of course, this does raise questions as to the usefulness of high-cyclic controlled bursts (HT83) in more traditional firearms. I suspect the utility there has to do with the fact that most high-rated infantry armor only reliably protects against one or two hits - when the target has semi-ablative armor, hitting with more shots per burst can be rather useful. (EDIT: Of course, it could also just be weapons manufacturers and/or their consumers thinking this is an awesome feature, despite it not giving any actual significant advantage)

Going back to beam weapons, this suggests a potential role for VRF-type versions. A lot of discussion about protecting from lasers relies on using ablative materials (in GURPS terms, semi-ablative armor), and indeed UT has such armor specifically for countering lasers. Having done an analysis of it, however, having an RoF 1 laser is often better than even an RoF 10 VRF laser - assuming equal weights (and assuming VRF doesn't add weight), the former has twice the damage of the latter, so aside from engaging an unarmored target from a range at which that +2 makes a really large difference in hit chance, the RoF 1 laser will generally outperform (it takes ~20 hits to deplete semi-ablative armor that's proof against twice your laser's damage to reduce it to just be proof against your laser's damage). Against fully-ablative DR, like a force screen, however, VRF will perform extremely well - indeed, you could have a weapon that can switch between RoF 1 and RoF 10# such that you use the latter to deplete the target's shields, then switch to the former to punch through their armor.

[Ulzgoroth]

Originally Posted by Varyon

Of course, this does raise questions as to the usefulness of high-cyclic controlled bursts (HT83) in more traditional firearms. I suspect the utility there has to do with the fact that most high-rated infantry armor only reliably protects against one or two hits - when the target has semi-ablative armor, hitting with more shots per burst can be rather useful. (EDIT: Of course, it could also just be weapons manufacturers and/or their consumers thinking this is an awesome feature, despite it not giving any actual significant advantage)

I suspect that those weapons have small enough rounds that high-cyclic bursts are actually a meaningful boost to effect on human targets. Kromm started the 'multiple hits doesn't matter' at GPMGs. Those are characterized by firing 'full power' rounds such as 7.62mm NATO. But most modern combat small arms don't do that, and the particular examples of HCCB in High Tech very much don't.

As a result they're more likely to need multiple hits to do their job, especially if loaded with AP rounds to compensate for their limited punch against armored targets.



GURPS UT lasers already get incredible power from their combination of accuracy and low recoil. Small-arms lasers are not so good at handling hard targets, it's true, but the ability to put a ludicrous amount of aggregate burst damage on precise locations makes them murder on non-hardened equipment. (And non-hardened personnel, of course, but those are comparatively fragile.) Stop a truck, shoot weapons out of your enemies' hands, demolish civilian infrastructure, all of it with a convenient carbine that also shoots people and runs on power cells.

Of course, some of that is to do with a flaw in the damage system, which has had a suggested patch for quite a while...