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Old 12-06-2011, 07:33 AM   #21
vicky_molokh
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Default Re: Changing Rapid Fire

Quote:
Originally Posted by OldSam View Post
Indeed, good point!

Overall the Rapid Fire rules are aimed primarily at small arms, where they work quite good. But using an abstract concept they make a reasonable compromise between complexity and playability IMHO, and I think it's very, very hard to find a better generic solution, so they made a good job anyway. Of course for very big targets it's not a really good rule but a lof of the upcoming issues can be solved just by background explanations of the GM.
G is for Generic.

We have RoF rules which are used everywhere, but are applicable only for TL8 small arms. Neither TL9 beam weapons nor even TL7 vehicle-mounted weapons are completely compatible with them. With TL9 vehicles and vehicular weapons it gets even worse.

Quote:
Originally Posted by Langy View Post
Those rules actually don't apply if the target isn't completely immobile; they only apply to things like hitting the broad side of a barn, or the ground, not a gigantic vehicle, even if the vehicle isn't moving fast enough to affect whether or not it's hit. Further, it's completely against the whole 'RoF is about hitting a point-target' idea.
Indeed, this is why I mentioned a Viper/X-Wing attacking a larger ship.
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Old 12-06-2011, 07:49 AM   #22
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Default Re: Changing Rapid Fire

Quote:
Originally Posted by vicky_molokh View Post
Indeed, this is why I mentioned a Viper/X-Wing attacking a larger ship.
You could also have it be a guy with an assault rifle trying to fire at an aircraft carrier as it leaves port, from maybe thirty yards away. To make it reasonable, his bullets might actually be tracker darts, with the more darts that hit the stronger the signal, so it actually matters if he hits or not.

But yes, the main problem with the Rapid Fire rules is its use in Spaceships combat using multi-second turns, and applying the Rapid Fire rules to independently targeted munitions like missile volleys.
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Old 12-06-2011, 08:10 AM   #23
vicky_molokh
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Default Re: Changing Rapid Fire

Quote:
Originally Posted by Langy View Post
You could also have it be a guy with an assault rifle trying to fire at an aircraft carrier as it leaves port, from maybe thirty yards away. To make it reasonable, his bullets might actually be tracker darts, with the more darts that hit the stronger the signal, so it actually matters if he hits or not.
Or how about Chip and Dale shooting at an inflatable raft with human baddies using their Rapid Micro Needler? ;)

On a more serious note, some sort of flak or other TL6 AA trooper shooting at a corn bomber. Or at a Kirov II airship - faster than Kirov I. ;)

Or shooting a charging T-Rex from an AK or PPSh in hopes that injuries will accumulate and stop it.

In general, though, some sort of AA activity seems like the most likely real-world case (and is applicable to WWII, one of the most serious GURPS settings).
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Old 12-06-2011, 08:27 AM   #24
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Default Re: Changing Rapid Fire

I always figured there was something strange about shotguns and the rapid fire rules. If you fire one shell from the canonical TL7 Auto Shotgun on p. B279 at a 1 yard stationary target ten yards away, you get
-4 range
-2 target size
+5 max aim bonus
+2 rapid fire bonus for nine "shots" (pellets)
+1 all out determined
= +2

Let's assume a skill 12 shooter and an average roll of 10, MoS 4 -> five pellets hit.

This is beginning professional skill level and so you'd expect this shooter to be able to hit pretty near a bull's eye at 10 yards range, but in order to get all pellets within a one yard target (which is pretty big at this distance) he actually needs to roll 6 or less. The most usual case is for most of the pellets to be on target, but a few to miss.

Now for a shotgun this seems remarkable because a proper shotgun simply will not have that much spread after 10 yards (indeed, up to 5 yards GURPS treats the mass of pellets as one solid slug). The conclusion is that it's almost impossible for a skill 12 shooter to correctly aim the weapon at the center of the target, and that most shots end up centered along the perimeter so that a few pellets can manage to miss. This seems wrong to me. Is it really this hard to aim a shotgun correctly at the center of the target?

I suspect that if you exchange the canonical 1x9 shell with birdshot or similar with larger number of pellets this will just get even stranger.
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Old 12-06-2011, 08:51 AM   #25
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Default Re: Changing Rapid Fire

Quote:
Originally Posted by Langy View Post
But yes, the main problem with the Rapid Fire rules is its use in Spaceships combat using multi-second turns, and applying the Rapid Fire rules to independently targeted munitions like missile volleys.
I don't think that one is a problem with the rapid fire rules so much as Spaceships misusing them. A houseruled rapid fire system that works for strafing, dogfighting, and assorted other situations of high autofire against large targets in regular GURPS combat, but doesn't make Spaceships combat work, is just fine.
Quote:
Originally Posted by bcd View Post
I always figured there was something strange about shotguns and the rapid fire rules. If you fire one shell from the canonical TL7 Auto Shotgun on p. B279 at a 1 yard stationary target ten yards away, you get
-4 range
-2 target size
+5 max aim bonus
+2 rapid fire bonus for nine "shots" (pellets)
+1 all out determined
= +2

Let's assume a skill 12 shooter and an average roll of 10, MoS 4 -> five pellets hit.

This is beginning professional skill level and so you'd expect this shooter to be able to hit pretty near a bull's eye at 10 yards range, but in order to get all pellets within a one yard target (which is pretty big at this distance) he actually needs to roll 6 or less. The most usual case is for most of the pellets to be on target, but a few to miss.

Now for a shotgun this seems remarkable because a proper shotgun simply will not have that much spread after 10 yards (indeed, up to 5 yards GURPS treats the mass of pellets as one solid slug). The conclusion is that it's almost impossible for a skill 12 shooter to correctly aim the weapon at the center of the target, and that most shots end up centered along the perimeter so that a few pellets can manage to miss. This seems wrong to me. Is it really this hard to aim a shotgun correctly at the center of the target?

I suspect that if you exchange the canonical 1x9 shell with birdshot or similar with larger number of pellets this will just get even stranger.
Careful...you haven't put a non-combat bonus on that, which implies that you're taking this shot in combat conditions. And for a shotgun with moderate RoF and rcl 1, you don't need all that much help to hit 100%.

The birdshot certainly does provide a clear example. It's also one where fixing the rapid fire mechanic alone would break the game. Birdshot does not tend to instantly kill or dismember people! You may need to combine it with an extended wounding system for that to work out better.
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Old 12-06-2011, 09:48 AM   #26
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Default Re: Changing Rapid Fire

A reasonable change (it does add more math) is:

Look up [Recoil+Rapid fire Bonus-Margin of Success-1] on Speed/range table. Divide the number of shots fired by the result in yards, rounding down, minimum 1, maximum shots fired.

This has a nice advantage: if MoS=Rapid Fire bonus+Recoil+1, then you hit with all shots. As MoS inherently includes the Rapid Fire bonus, this means that if you fired well enough to hit with MoS=Recoil+1, WITHOUT any rapid fire bonus you hit with all shots: shooting faster, at constant recoil, doesn't make you less accurate.

It suffers a little from the minimum number of hits slowly rising above 1, but this isn't very pronounced. Unfortunately, the low RoF portion of the rapid fire table is linear rather than logarithmic, and the high RoF portion uses a different base than the speed/range table, so combining the two won't scale perfectly.

Examples:
RoF 3, Recoil 2 [generic pistol]) MoS=0, 1 hit (3/3); MoS=2, 2 hits; MoS=3, 3 hits
RoF 8, Recoil 2 [M2]) MoS=0, 1 hit; MoS=1, 2 hits; MoS=2, 4 hits; MoS=3 5 hits; MoS=4, 8 hits
RoF 9, Recoil 2 [M16A2]) MoS=0, 1 hits; MoS=2, 3 hits; MoS=3, 4 hits; MoS=4, 6 hits, MoS=5, 9 hits (some break-point issues with MoS=1)
RoF 100, Recoil 2 [Vulcan]) MoS=0, 2 hits; MoS=2, 3 hits ... MoS=10, 100 hits
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Old 12-06-2011, 03:12 PM   #27
Tyneras
 
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Default Re: Changing Rapid Fire

Quote:
Originally Posted by jacobmuller View Post
I am with you in spirit if not in form.
The explanations for small arms fire (excess rounds don't so much miss as have merely cosmetic affect) kind of loses charm when you're working with salvos of multi-warhead missiles capable of vaporising an aircraft carrier.
Though I'd rather not resort to calculus or large spreadsheets.
To paraphrase one of our beloved authors: A GURPS solution should be expressible as a simple formula that may then be illustrated as a simple table.
You're at least halfway there.
Which half? The rule I literally dreamed up is simple enough that I can do it in my head on the fly, although I know math ability varies dramatically enough among gamers that that anecdote means basically nothing.
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Old 12-06-2011, 08:54 PM   #28
sir_pudding
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Default Re: Changing Rapid Fire

Quote:
Originally Posted by vicky_molokh View Post
Under Basic Set rules, that means that while they're both in flight, an unaimed, not electronically aided attack, with base skill 24 (cinematically good), +4 (for RoF 20), -18 for range, total 24+4-18=28-18=10. So it has roughly half chance to hit with one bullet. Let me visualize this for you:


The target is 1500yds wide. The range is 2000yds. The shooter is abnormally skilled. And 19 out of 20 bullets (maybe all 20) will fail to hit this 1500-wide target. 95% of bullets will go 750yds (375 if we include shorter sides) to the side at 2000yds. With a Rcl 1 ('recoilless') weapon.
Actually no. Each shot that "misses" has a 9 or less chance to impact the hull 1 yd to either side, by RAW. Which is also weird, but maybe less so. It's unclear what happens to any subsequent misses, do they just keep rolling until they hit? It should be possible to miss with some shots in many of these situations.

Really if you want to engage the thing as an area target, why not just use suppression fire against the interior. Then the hull counts as cover and basically can't be missed. :)
Quote:
If you use Spaceships rules, things aren't better in any meaningful sense.
Those rules are a problem because they stretch the Rapid Fire rules to beyond the breaking point.

Really I don't think the system handles combat with large vehicles all that well at all right now. Which makes sense with only the skeletal chapter in the Basic Set on the subject.
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Old 12-06-2011, 11:01 PM   #29
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Default Re: Changing Rapid Fire

Quote:
Originally Posted by vicky_molokh View Post
Really?
Get, say, a BSG Viper. Its cannon has RoF 20/second, or 400 per 20-second round in GSS. It is roughly SM+4. Give it Rcl 1 for the fixed mount, we're feeling generous.
In a training exercise, let it target the BS-F-G, 1½km in length (SM+17).

Both ships are moving at a constant speed, and the absolute distance mod is greater than absolute size mod (1 mile vs 1500yd), so we get speed mods but no dodge.

Under Basic Set rules, that means that while they're both in flight, an unaimed, not electronically aided attack, with base skill 24 (cinematically good), +4 (for RoF 20), -18 for range, total 24+4-18=28-18=10. So it has roughly half chance to hit with one bullet. Let me visualize this for you:

The target is 1500yds wide. The range is 2000yds. The shooter is abnormally skilled. And 19 out of 20 bullets (maybe all 20) will fail to hit this 1500-wide target. 95% of bullets will go 750yds (375 if we include shorter sides) to the side at 2000yds. With a Rcl 1 ('recoilless') weapon.

If you use Spaceships rules, things aren't better in any meaningful sense.
Actually I don't think that is right.

Pg. 469 states:

Quote:
It is also important to consider apparent relative speed. If two cars
are rushing toward each other on a collision course, the speed of one,
relative to the other, may be over 120 mph . . . but the apparent relative
speed is zero. Only apply speed penalties for crossing targets. Ignore the
speed of targets moving more or less directly toward or away from you.
So in your example the Battleship is 1500 yrds long (+17), 1 mile away, (-18), Rof 20 (+4), for a total of +3 to that 24 skill. He's going to hit with every shot.

Still, I think being a mile away is a little extreme if you are something like an X-Wing trying to strafe a star destroyer. You'd probably wait to fire until you were a little closer and would have plenty of time to aim as you approached.
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Old 12-06-2011, 11:57 PM   #30
Ulzgoroth
 
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Default Re: Changing Rapid Fire

Quote:
Originally Posted by Snaps View Post
Actually I don't think that is right.

Pg. 469 states:

Quote:
It is also important to consider apparent relative speed. If two cars
are rushing toward each other on a collision course, the speed of one,
relative to the other, may be over 120 mph . . . but the apparent relative
speed is zero. Only apply speed penalties for crossing targets. Ignore the
speed of targets moving more or less directly toward or away from you.
Ok, first, thank you for that page reference. I'm pretty sure I've been challenged on the existence of that quote before and been unable to find it...

However, since vicky_molokh mentioned speed mods but never actually put them into the calculation, I'm not sure how that's relevant.
Quote:
Originally Posted by Snaps View Post
So in your example the Battleship is 1500 yrds long (+17), 1 mile away, (-18), Rof 20 (+4), for a total of +3 to that 24 skill. He's going to hit with every shot.
However, he does seem to have dropped the target size modifier, unaccountably, so this is mostly right. However, skill 27 only results in all 20 shots hitting if you roll a MoS of 19 or better, which requires rolling an 8 or lower. Not impossible, but no sure thing. Even with the Rcl 1 weapon.
Quote:
Originally Posted by Snaps View Post
Still, I think being a mile away is a little extreme if you are something like an X-Wing trying to strafe a star destroyer. You'd probably wait to fire until you were a little closer and would have plenty of time to aim as you approached.
You'd wait to fire until your target filled over 52 degrees? Unless your weapons' effective range is shorter than that of a modern rifle, I rather doubt that.

Aiming, on much the same hand, seems pretty much impossible. In a one-man fighter, aiming means not piloting, and so does taking an Attack or All Out Attack maneuver to be allowed to benefit from aiming. In the dogfighting furballs of Star Wars or BSG, letting your ship just drift for multiple consecutive seconds is more or less suicidal.
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