Weapon Composition

[Ulzgoroth]

Originally Posted by Dunadin777

True and true. But when the armored warrior gets a major wound from a bandit's sling through his segmented plate, then it's a problem. I selected it for the bandits because it's a neat, unusual weapon, but I don't think that should've happened without hitting an unarmored spot, a chink, or a critical. It had none of them.

Ah. I would cringe at that one, though not so much for the injury (again, pretty powerful weapon) as for the implied ability to penetrate heavy armor. Light segmented plate is just not all that much protection, but if you're getting 8 damage to start with (which seems implied) you could do fairly disturbing things like mash up somebody's brain right through a roman legionary helmet.

[DouglasCole]

By the way, to get "realistic" sling damage, we need to know the velocity and mass of the projectile. Once we get energy, if we have any data on penetrations, esp of metal armor (likely THIN metal armor) we can assign appropriate injury levels.

First order, if we can determine the penetration of even one sling stone against something real, we can scale the rest by the effective ST of the thrower. Bows don't work very well that way because of efficiency issues, but bow of constant efficiency firing equal-weight arrows that varies in the ST required to draw it will vary linearly in that ST. Slings would be similar.

Thing about slings (and fastballs) is we need a better blunt trauma rule for non-penetrating injuries, since you can probably get your bell rung pretty hard by a non-penetrating stone.

[DanHoward]

Thom Richardson made a detailed study of an Egyptian sling found at El Lahun in Fayum, dating to the eighth century B.C. His reconstructions were 1450 mm in length and weighed 45 g. He discovered that when stones were used, the results were very inconsistent, even when shooting stones of the same weight. Average range for stones weighing 45-75 g was 90 m, the range for stones weighing 80-85 g was 84 m, and the range for stones weighing 85-160 g was 82 m.

He then tested two types of lead shot. One was spherical ('ball') and the other was almond shaped ('shot'). The 38 g balls averaged 114 m and the 100 g balls averaged 107 m. The 40 g shot (29 x 18 x 13 mm) travelled 145 m on average and the 85 g shot (39 x 22 x 16 mm) averaged 120 m. Overall, lead outranged stone by about 50%.

Richardson did ballistic testing of some of his shots and recorded the speed at a distance of 3 m from the point of release. The 80-100 g stones averaged 30.3 m/s, the 100 g lead ball averaged 30.5 m/s, the 40 g lead shot averaged 30.6 m/s, and the 85 g shot averaged 31.2 m/s.

Source: T. Richardson, "The ballistics of the sling," Royal Armouries Yearbook, Vol. 3, (Leeds: Royal Armouries, 1998)

Nothing on penetration, sorry :(

[DouglasCole]

Originally Posted by DanHoward

Thom Richardson . . . Nothing on penetration, sorry :(

Great info, though.


The constant velocity means that the weight of the projectile isn't the rate-limiting step. I would guess that what limits the velocity is the aerodynamic drag on the overall system, since stones and shot that were different by 2x or more had basically identical velocities. Bigger went a bit lesser range than smaller, and sculpted rugby balls were a bit better (25-30%) than round.

One stone was pretty much an outlier. The rest had more or less the same KE (41-46 J) and MV (2.7-3.1 kg m/s). A war arrow (.09 kg) fired from a strong bow at 52m/s (125J) will have about 4.7 kg m/s of momentum.

So that particular sling had about 60% of the penetrative potential of an arrow based on sqrt (KE). It also has about 60% of the momentum-based blunt trauma capacity of the war arrow above.

If that arrow does about 1d+1, which is about where the bow article I wrote will put it (4.5 pts) then not accounting for cross section (though war arrows were often 11-13mm in frontal cross-section, maybe half that of the stone or shot. That will, in GURPS, result in about a 10% loss in penetrative ability.

All in all, about 53% of the penetrative capability, or 2.4 points of damage. Calling this 1d-1 won't break anything. Low sectional density and poor construction (stone and lead) relative to other penetrators (steel, hardened or not, and jacketed lead) might earn it a (0.5) armor divisor.

So, the questions I have no data for:

Does the strength of the slinger matter much? Does being able to whip the thing around twice as hard lead to, for example, 20% more velocity? (fourth root of force) due to drag increasing as you spin harder? Is it massively skill dependent? Is there a skill above which you're only aiming better, but not any faster?

In terms of injury, this is straight-up blunt trauma. Crushing or piercing, clearly, and large enough that it might be considered a + type damage. It will injure much better than it will penetrate.

[DanHoward]

Originally Posted by DouglasCole

Does the strength of the slinger matter much? Does being able to whip the thing around twice as hard lead to, for example, 20% more velocity? (fourth root of force) due to drag increasing as you spin harder? Is it massively skill dependent?

Also need to determine how altering the length and weight of the sling effects the projectile.

[seasong]

Executive Summary
RAW* has the following effects:

1. A stone age axe can hack right through leather short of heavy leather.
2. A stone age axe can barely bruise through heavy layered cloth.
3. A half-pound stick can break a rib through the same.
4. If you blunt the head of the axe, heavy layered cloth cannot help you.

Of the above effects, only (3) appears to be realistic.

* RAW, in this case, means with Low-Tech and Low-Tech Companion 1-3, including the Blunt Trauma and Edged Weapons optional rule in Low-Tech, p. 102, which was designed to make (1) more realistic.

Introduction
Ed is a TL0 ST 12 (1d-1/1d+2) warrior. That's reasonably beefy (50% stronger than the heroic average that GURPS assumes), but quite reasonable for a typical warrior.

Ed often attacks people wearing everything from loin cloth to heavy layered cloth armor (DR 0-4). Ed has some emotional issues.

Ed owns a round mace, a short baton, a spear, and axe, and his mighty fists. The average damages under RAW are:

Swung Weapon      DR0  DR1  DR2  DR3  DR4
Round Mace, 1H    7.5  6.5  5.5  4.5  3.5
Round Mace, 2H    8.5  7.5  6.5  5.5  4.5
Short Baton, sw   4.5  3.5  2.5  1.7  1.0
Axe, 1H           9.8  6.3  2.5  1.0  0.2
Axe, 2H          11.3  8.0  4.0  1.7  0.5

Thrust Weapon     DR0  DR1  DR2  DR3  DR4
Short Baton, th   2.5  1.7  1.0  0.5  0.2
Fist              1.7  1.0  0.5  0.2  0
Spear, 1H         7.0  3.3  1.0  0    0
Spear, 2H         9.0  5.0  2.0  0.3  0

Basic Conclusion
Dan Howard has said, and I agree, that a mace should be superior to a stone-age axe against armor. But even a half-pound stick is a toss-up compared to the axe.

Dan Howard has said, and I agree, that a stone-age axe should have an almost impossible time penetrating any kind of armor. But the stone-age axe cuts medium or lighter leather pretty easily. And it can't even bruise through heavier armors, which has nothing to do with penetration.

So, here is the house rule I've tried to come up with to fix this issue. It replaces the armor divisor for stone weapons and the Blunt Trauma and Edged Weapons optional rule in Low-Tech, p. 102.

House Rule
Armor attempts to convert all kinetic damage (cr, cut, imp, pi) into crushing damage.

Cutting damage has Edge Protection (EP) of DR×2; impaling and piercing damage has EP of DR×1 (which matters - impaling attacks which fail to penetrate DR won't benefit from Keen or Very Keen when calculating blunt trauma!).

Originally Posted by Optional: Different Strokes

The cutting EP above is an average, covering a wide variety of different types of weapon attack areas. For a more realistic value, use DR×3 for slashing weapons (sharp claws, whips, urumi, and similar), DR×2 for hacking weapons (swords), and DR×1.5 for chopping weapons (axes). This is optional because it adds more complexity, and is not always useful.

If total damage exceeds EP, treat the damage normally. Otherwise, treat the attack as crushing (eliminate damage bonuses from fine or very fine) and reduce cutting damage by a further -1.

The Tough Skin limitation does not provide EP.

Originally Posted by Optional: Hide Protection

DR with the Tough Skin limitation does provide EP, but a cutting, impaling, or piercing attack still counts as a scratch for purposes of any follow-up effects, infection, and so on. This is optional because some people will feel it's more realistic, and others will feel it's less realistic. Pick your poison.

Any weapon composition (stone, horn, and so on) which has an (0.5) armor divisor, instead quadruples EP. Thus, a stone-tipped arrow would have EP of DR×4 rather than DR×1, and a sword would have EP of DR×8 rather than DR×2.

Here are the same tables, with the revised mechanics (note, I'm using the Different Strokes optional rule):

Swung Weapon      DR0  DR1  DR2  DR3  DR4
Round Mace, 1H    7.5  6.5  5.5  4.5  3.5
Round Mace, 2H    8.5  7.5  6.5  5.5  4.5
Short Baton, sw   4.5  3.5  2.5  1.7  1.0
Axe, 1H          11.0  8.5  4.5  3.5  2.5
Axe, 2H          12.5 10.5  5.5  4.5  3.5

Thrust Weapon     DR0  DR1  DR2  DR3  DR4
Short Baton, th   2.5  1.7  1.0  0.5  0.2
Fist              1.7  1.0  0.5  0.2  0
Spear, 1H         9.0  6.0  2.5  1.7  1.0
Spear, 2H        11.0  8.2  3.5  2.5  1.7

[Trachmyr]

Ok, my comments on your current version.

1. I like the name change to the more familiar EP

2. I think you should put back in the 1.5 EP, 3 EP for Unbalanced Cutting Weapons, and Slashing Weapon (Anything with Reach C or C,1, plus Tip Slashes) as an optional rule.

3. I don't agree with losing quality bonuses to see if you penetrate, only if you fail to penetrate. What's more likely to cut through a piece of leather, Obsidian, Flint or ground Jade?

4. Perhaps the x+1 value was too generous, but 4x EP seems overkill... what's the numbers with 2x? Perhaps set Chipped Stone to 2x and ground stone to 3x or 4x?

5. While I agree that weapons that fail to penetrate should not automaticaly get the +1 damage for flanges, I do believe it's a valid design option on cutting (not impaling) weapons to get a bit of a boost when they fail to penetrate EP.

6. After carefule consideration and number running, I think I now favor the Tough Skin benefits from EP route. My main holdout was that it diverged from the EP rules in LT, but after an unbiased reexamination, I think Tough Skin should benefit. Sorry about the flip flop.

7. Overall, very nice work!

[Dunadin777]

Originally Posted by seasong

Executive Summary
RAW* has the following effects:

This is a great write-up. The first two sections really address my earlier concerns quite well. Perhaps if I'd declined to comment 'til then...oh well.

I do have a question regarding this house-rule (with the optional parts included): how would you class the different types of biting attacks?

[seasong]

Originally Posted by Trachmyr

1. I like the name change to the more familiar EP

Yeah, originally I was trying to match Low-Tech, which scrupulously avoids the word, but... clarity, Seasong, clarity.

Originally Posted by Trachmyr

2. I think you should put back in the 1.5 EP, 3 EP for Unbalanced Cutting Weapons, and Slashing Weapon (Anything with Reach C or C,1, plus Tip Slashes) as an optional rule.

I think I did? It's in a quote box as Optional: Different Strokes.

Originally Posted by Trachmyr

3. I don't agree with losing quality bonuses to see if you penetrate, only if you fail to penetrate. What's more likely to cut through a piece of leather, Obsidian, Flint or ground Jade?

My wording may have been unclear. The quality bonus applies for purposes of exceeding EP. You only lose the quality bonus if you failed to exceed EP.

Originally Posted by Trachmyr

4. Perhaps the x+1 value was too generous, but 4x EP seems overkill... what's the numbers with 2x? Perhaps set Chipped Stone to 2x and ground stone to 3x or 4x?

With 2x:

Swung Weapon      DR0  DR1  DR2  DR3  DR4
Round Mace, 1H    7.5  6.5  5.5  4.5  3.5
Round Mace, 2H    8.5  7.5  6.5  5.5  4.5
Short Baton, sw   4.5  3.5  2.5  1.7  1.0
Axe, 1H          11.0  9.5  7.2  4.2  2.5
Axe, 2H          12.5 11.0  9.0  6.0  3.5

Thrust Weapon     DR0  DR1  DR2  DR3  DR4
Short Baton, th   2.5  1.7  1.0  0.5  0.2
Fist              1.7  1.0  0.5  0.2  0
Spear, 1H         9.0  6.8  4.5  2.3  1.0
Spear, 2H        11.0  9.0  6.5  4.0  1.7

As you can see, axes and spears become quite good at penetrating armor, and the axe starts outperforming the mace.

4x seems pretty harsh, but is the lowest value that both prevents the axe from cutting through most armors, and lets the mace win in straight attacks against armor.

Originally Posted by Trachmyr

5. While I agree that weapons that fail to penetrate should not automaticaly get the +1 damage for flanges, I do believe it's a valid design option on cutting (not impaling) weapons to get a bit of a boost when they fail to penetrate EP.

Compared to a padded, blunt weapon, both cutting and impaling weapons get a boost for having a narrow line or pointed impact. And again, the goal was to let the wookie... I mean, round mace... win.

Originally Posted by Trachmyr

6. After carefule consideration and number running, I think I now favor the Tough Skin benefits from EP route. My main holdout was that it diverged from the EP rules in LT, but after an unbiased reexamination, I think Tough Skin should benefit. Sorry about the flip flop.

7. Overall, very nice work!

Thanks! And no worries about flip-flopping. I've changed a number of opinions since starting the thread :-).

Originally Posted by Dunadin777

I do have a question regarding this house-rule (with the optional parts included): how would you class the different types of biting attacks?

I would treat most sharp teeth as x1.5; they don't have the same wide surface area as a sword. Piercing and impaling teeth would be treated as piercing or impaling attacks.