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Old 11-26-2008, 08:21 AM   #11
Bruno
 
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Default Re: Bulk and ST for missile weapons

Quote:
Originally Posted by Gudiomen
It's also weird that there aren't rules for modifying the weight of a bow, whether it be ST10 or ST20... like you said, increasing the limb length adds more material.
I'm almost inclined to go with the Dungeon Fantasy rules for scaling weapons up, going with double weight for double ST (starting with the listed weapon), and then interpolating. But that's including making the whole weapon large (for instance increasing the draw length on a longbow by 50%)... Bleh.
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Old 11-26-2008, 09:13 AM   #12
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Default Re: Bulk and ST for missile weapons

Quote:
Originally Posted by Gudiomen
It's also weird that there aren't rules for modifying the weight of a bow, whether it be ST10 or ST20... like you said, increasing the limb length adds more material. One possible justification is that it's possible to pull this off with changes in angle of the cord, curved design, type of wood, and whatever else is relevant (I don't know much about archery or bow-making/fletching).

Of course, crossbows have additional parts that scale with limb breadth, so even if the difference of weight for limbs is negligible the rest of the paraphernalia will still increase the weight a little.
For crossbows, at least, if you increase the draw weight but don't increase the power stroke (the distance the string travels), you don't add much initial energy to the bolt at all.

That's why my treatment assumes that it's possible to vary prod size relative to ST and thus effiicency. Some steel bows will be extremely ineffient, but the high absolute draw will still allow them to retain effectiveness.

Quote:
Originally Posted by Gudiomen
While crossbows in history could grow to human-size and needed to be cocked with a stirrup and your foot, I don't think the crossbows in Basic/Martial-Arts get into that, they're just the ordinary 2-handed variety.

I also think that the realistic resolution of these crossbows also reflect the lack of material about them. Sure, we can differentiate the subtleties between several types of rifles, pistols and SMGs, we know a lot about them, and they're produced in series that share common traits. X-Bows weren't and we don't know a lot about them. "Small", "Medium" and "Big" might suffice, and even if you change the statistics a little, it's pretty believable that a crossbow existed with those stats, as they probably varied a lot even in the same place, as crafting wasn't industrialized.
I'm confining myself to handheld weapons usable by SM 0 people. I plan to include tables that allow one to select the desired draw weight, material used for the prod and the approximate size of the prod relative to draw weight.

I'll also include several worked examples and note what ST can easily draw them.

Quote:
Originally Posted by Gudiomen
I realize that's not what you're looking for, but for now eye-balling is probably going to give you the best results, and even if they're not perfect, there probably were some crossbows around that could perform like that and you can get away with it, unless you're too optimistic (which I don't think is the case).

I think there are too many variables we don't know how to quantify in order to reach a weight, bulk and minST value. I suggest taking the smallest crossbow you can find historically and giving it the lowest weight, bulk and minST value in the rules, likewise for the biggest historical crossbow that could be held, cocked and fired with 2 hands only. Everything else fits in between.
I'm looking for help with eyeballing it. I've already benchmarked -3 Bulk as the handiest possible, now I need a good guess for the 20+ lbs. monsters mentioned above.
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Old 11-26-2008, 12:53 PM   #13
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Default Re: Bulk and ST for missile weapons

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Originally Posted by Icelander
I'm looking for help with eyeballing it. I've already benchmarked -3 Bulk as the handiest possible, now I need a good guess for the 20+ lbs. monsters mentioned above.
Well, looking over the crossbows, bows and firearms it's safe to say the maximum Bulk penalty should be around -6/-7. Nothing I see has a bigger bulk number (except longbows), and a crossbow shouldn't be harder to fire while moving or to hide than a huge bow (which is -6/-7), it definately shouldn't be as much as -8, since any 2-handed crossbow, no matter how massive, if usable will be easier to fire on the run than a longbow, IMHO.

Since a regular crossbow is -6, let's assume the largest beast of it's kind will be -7, making it's larger dimensions comparable to an actual bow (regular or composite).

Weight is trickier, but using Bruno's suggestion, lets take a SM approach. Direct proportion is out, since we don't scale up the entire crossbow, only the relevant bits. Let's assume half, it's as good a guess as any unless somebody can figure out just what bits need to get bigger and how much they weigh. If a regular crossbow weighs 6 lbs for ST7, then ST14 will weigh 9lbs, and ST21 will weigh 12lbs. Damn heavy, but not impossible to use, probably the biggest crossbow a human can use effectively (using a Goat's Foot and a perk for +2 ST with Crossbows you only need ST15 to do it).

I'll say this though: from what Basic seems to hint, or maybe that's just my understanding, high ST bows and crossbows are not meant to be either heavier or more expensive. That's not realistic of course, but maybe the mechanic I suggested might be too harsh. You be the judge.

Edit... so a 18lb crossbow would require ST28 and theoretically a bulk rating of -7, although something this heavy probably doesn't qualify for regular 2-handed use anymore (even with the perk and a Goat's Foot, you'd need ST22 to cock it), at this point -8 for bulk might be believable.

Last edited by Gudiomen; 11-26-2008 at 01:00 PM.
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Old 11-27-2008, 02:54 PM   #14
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Default Re: Bulk and ST for missile weapons

Quote:
Originally Posted by Gudiomen
Well, looking over the crossbows, bows and firearms it's safe to say the maximum Bulk penalty should be around -6/-7. Nothing I see has a bigger bulk number (except longbows), and a crossbow shouldn't be harder to fire while moving or to hide than a huge bow (which is -6/-7), it definately shouldn't be as much as -8, since any 2-handed crossbow, no matter how massive, if usable will be easier to fire on the run than a longbow, IMHO.
I don't agree.

I don't think any crossbow intended to be used as a battlefield weapon will go over this, but many crossbows were intended for sieges only.

And since a regular crossbow with a selfbow prod and weighting only 6 lbs. is Bulk -6, I'd think that siege crossbows of more than three times the weight would be much more.

Let's also keep in mind that a crossbow has much of its weight concentrated in the front. It's nowhere near as handy as a rifle of equal weight and length. This causes no problems when fired from a rest or even a stand on a castle wall, but it's hard to run and shoot with a monster like that.

Quote:
Originally Posted by Gudiomen
Since a regular crossbow is -6, let's assume the largest beast of it's kind will be -7, making it's larger dimensions comparable to an actual bow (regular or composite).
I don't think it's fair to assume that a small crossbow designed for battlefield use and a huge one designed for be fired only from a mount on a castle wall would differ only by -1 in Bulk.

Quote:
Originally Posted by Gudiomen
Weight is trickier, but using Bruno's suggestion, lets take a SM approach. Direct proportion is out, since we don't scale up the entire crossbow, only the relevant bits. Let's assume half, it's as good a guess as any unless somebody can figure out just what bits need to get bigger and how much they weigh. If a regular crossbow weighs 6 lbs for ST7, then ST14 will weigh 9lbs, and ST21 will weigh 12lbs. Damn heavy, but not impossible to use, probably the biggest crossbow a human can use effectively (using a Goat's Foot and a perk for +2 ST with Crossbows you only need ST15 to do it).

I'll say this though: from what Basic seems to hint, or maybe that's just my understanding, high ST bows and crossbows are not meant to be either heavier or more expensive. That's not realistic of course, but maybe the mechanic I suggested might be too harsh. You be the judge.

Edit... so a 18lb crossbow would require ST28 and theoretically a bulk rating of -7, although something this heavy probably doesn't qualify for regular 2-handed use anymore (even with the perk and a Goat's Foot, you'd need ST22 to cock it), at this point -8 for bulk might be believable.
We know the range and penetrating damage of a 18 lbs. siege crossbow. We can also look up the range and damage of several other weights.

I don't have any difference finding weights. I need to know what ST a given weight requires in order to use the weapon.

And I'm not speaking of the ST to cock the weapon or the ST of the attack it delivers. I'm speaking of the MinST stat that ranged weapons have.
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Old 11-27-2008, 05:17 PM   #15
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Default Re: Bulk and ST for missile weapons

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Originally Posted by Icelander
I don't think it's fair to assume that a small crossbow designed for battlefield use and a huge one designed for be fired only from a mount on a castle wall would differ only by -1 in Bulk.
I thought you said you were only talking about regular 2-handed crossbows, not siege or mounted ones. If that's the case, then hell yes, bulk -7 doesn't cover it.

As for the small differences in Bulk within "hands-held" crossbows I think a 1 point difference can be a big one, I don't view bulk in a linear scale. It's more of a bell curve to me, on the extremes a +/-1 covers a lot of differences, "low resolution", while near the middle (-3 to -5) a single point of difference can point to subtle differences. This is a personal view though, I feel that once it's pretty darn big, just making it bigger won't matter as much, same goes for small. However, I do agree that -7 or even -8 is generous for siege crossbows, but those are not your garden variety and I didn't think we were discussing them.

Edit: as for minST, yeah I screwed that up, got that mixed up with the ST to actually cock and fire the x-bow/bow...
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Old 11-27-2008, 05:23 PM   #16
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Default Re: Bulk and ST for missile weapons

Quote:
Originally Posted by Gudiomen
I thought you said you were only talking about regular 2-handed crossbows, not siege or mounted ones. If that's the case, then hell yes, bulk -7 doesn't cover it.

As for the small differences in Bulk within "hands-held" crossbows I think a 1 point difference can be a big one, I don't view bulk in a linear scale. It's more of a bell curve to me, on the extremes a +/-1 covers a lot of differences, "low resolution", while near the middle (-3 to -5) a single point of difference can point to subtle differences. This is a personal view though, I feel that once it's pretty darn big, just making it bigger won't matter as much, same goes for small. However, I do agree that -7 or even -8 is generous for siege crossbows, but those are not your garden variety and I didn't think we were discussing them.

Edit: as for minST, yeah I screwed that up, got that mixed up with the ST to actually cock and fire the x-bow/bow...
I'm discussing any weapon that can be used as a handheld crossbow.

Most of the larger variety were usually only used in sieges, but nothing prevents a PC from carrying it around. Well, except high Bulk.

The limiting factor with a high ST crossbow is that efficiency drops when you don't have enough draw length. The lightest draw crossbows might actually achieve bow-like efficiency, but the 1200lb monsters extraordinarily energy inefficient.

This is because increased the size of the prod at the same ratio as draw weight would produce bows too large to use comfortably. Hence, it seems from the historical record that Bulk was a factor that actively limited crossbow design.

So I want characters to have to select whether they want a powerful and efficient bow, which will be prohibitively bulky, or if they're willing to accept inefficiency in order to have a more comfortable weapon.
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Old 11-27-2008, 05:34 PM   #17
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Default Re: Bulk and ST for missile weapons

Unfortunately, there don't seem to be strips and pieces of rules enough to lead to gameable stats, or even a precise definition of Bulk. At this point, I don't know nearly enough to even guess, and everybody else seems to have drifted from the issue.

Maybe if you posted the material you got from historical crossbows?
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Old 11-27-2008, 05:55 PM   #18
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Default Re: Bulk and ST for missile weapons

Quote:
Originally Posted by Gudiomen
Unfortunately, there don't seem to be strips and pieces of rules enough to lead to gameable stats, or even a precise definition of Bulk. At this point, I don't know nearly enough to even guess, and everybody else seems to have drifted from the issue.
Indeed. There is a noticeable dearth of rules.

Quote:
Originally Posted by Gudiomen
Maybe if you posted the material you got from historical crossbows?
You can see a short book preview that addresses the issue here.
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Old 11-30-2008, 12:30 AM   #19
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Default Re: Bulk and ST for missile weapons

First, I took the time to write and research this throughly and Have actually submitted the idea to Pyramid for an article as it leads to some neat stuff.

The short version is this.

If you look up the Mary Rose you'll find a bunch of LongBow Dimensions.

Bulk Vs Str. Its not as big deal as you might think. You can Bump up the STR on a Bow/Crossbow without adding a signifigant amount to Bulk mainly becaue the length is the dominant factor contributing to the bulk as the 2-3 pound weight isnt generally considered bulky.

If the article gets rejected, I may publish the reults here because it is something that needs to be addressed.
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Old 11-30-2008, 08:58 PM   #20
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Default Re: Bulk and ST for missile weapons

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If you look up the Mary Rose you'll find a bunch of LongBow Dimensions.
True. But those, I think, are not the ones we were having problems with. Nor were other dimensions, as these are accessible from the historical record.

The problem lies in relating these real world dimensions to the GURPS mechanics of Bulk and MinST.

Quote:
Originally Posted by Nymdok
Bulk Vs Str. Its not as big deal as you might think. You can Bump up the STR on a Bow/Crossbow without adding a signifigant amount to Bulk mainly becaue the length is the dominant factor contributing to the bulk as the 2-3 pound weight isnt generally considered bulky.
One can certainly increase the draw weight of a crossbow without increasing the width and hence the draw length.

But that would result in a very inefficient weapon, since so little of the additional stored energy would be transmitted to the bolt in the form of initial velocity. I do not deny that it was done in the past, often enough, since with enough energy the lack efficiency could be tolerated and would still result in gains in absolute projectile energy.

But GURPS stats for the weapon would need to account for the lack of efficiency. A 760lb crossbow with a small prod and consequent short power stroke might not be any more effective than a 70lb bow with a much longer draw length.
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