Primitive and early weapons, Kinda T2K......

[.45cultist]

Has anyone looked at the Challenge No. 66 article "Yearning for Antiquity"?

[unkated]

I had 3 bow weapons I devised using the formulae from the Infantry Weapons Guide:

70-lb compound bow shooting a 17 gm arrow (arrow weight from an on-line source; not sure how much I trust it).
315 fps
Dmg: D6-1
Pen: Nil

(Typical) English Longbow (ca. 1300) shooting 58 gm arrow
600 fps
Dmg: 2
Pen: 1-Nil

Barnett Ghost 385 Crossbow shooting 400 gr (25.9 gm) bolt
385 fps
Dmg: 1
Pen: Nil

I will confess that I don't know much about bow mechanics, or how to (properly) translate lbs of pull to fps (or even how to calculate if a user is using all of the available power)

Now, you may not like the way damage is calculated in T2K. However, let me point out that all the other weapons in the game are calculated using the same method, however flawed; it does make for a viable way to compare weapons.

There is the issue in that formulae presented assumes that a bullet is a bullet is a bullet for comparing penetration; AP bullets are treated no different (perhaps the designers felt that at game scale & granularity, it doesn't). And it does not account for whether there is difference in the dynamics of target strike by an arrow, bolt, dart, or javelin.

(But then, T2K is assuming that primitive weapons will be scarce and therefore unimportant compared to gunplay.)

You can of course, change toa difference combat better designed to deal with non-firearm weaponry.

Uncle Ted

[swaghauler]

Here are some basic archery concepts and how they relate to archery in the real world. I'm guessing the Forum will have to work out which concepts are relevant to the game and how to apply them to the game engine being used.

The Characteristics of a Bow (or Crossbow):

1) Draw Weight: This is the amount of "pull weight," measured in pounds in the US, To draw back the bow. Common convention has Draw Weight ranging from 20lbs to 200lbs for a normal maximum (there are rumored 240lb bows, but I have never seen evidence of one). Draw Weights for crossbows range from 20lbs up to 500lbs for a crossbow that can be cocked by a cord or "goat's foot" lever (heavier crossbows require a windlass device to cock). I use 20lbs Draw Weight per point of STR for bows and 50lbs Draw Weight per point of STR for crossbows and list this as the STR needed to use this weapon. I think Draw Weight should be the primary measure of damage. When you look at the speed stats of bows published online, the standard bow Draw Weight used is 70lbs. Most modern Compound Bows can adjust their Draw Weight by about 10lbs in either direction. This task requires a skilled bow smith/boyer (AVE: Archery check?) to avoid damaging the bow's cam and pulley system.

Letoff: Compound Bows (and ONLY Compound Bows) have a feature called "Letoff." This is a point in the draw where the cams reach a "hold point" that takes most of the weight of the draw OFF of the shooter. This reduces the STR needed to hold back the bow string so the shooter can aim at a target. The typical "Letoff" of a Compound Bow is 80%, meaning that a standard 70lb Bow will only require 14lbs (STR 1) to hold at full extension. This "Letoff" is keyed to the cams and this means that you need to pull the Compound Bow back to the Draw Length it is set for to ensure "Letoff" occurs. Not pulling back that far not only prevents "letoff" from activating (requiring the shooter above to hold 70lbs/STR 4), but can damage the bow by causing "whiplash" which causes damage to the cables and cams (this is why you never "dry fire" compound bows). Composite Bows, Modern Longbows, Recurve Bows, and Self Bows DO NOT have this feature and you MUST hold their ENTIRE Draw Weight (which makes them harder to aim). They also have NO cam reset or letoff either, which means you can shoot shorter arrows from these bows (see below under Draw Length).

Minimum Arrow Weight: A bow's Draw Weight determines the minimum weight of arrow that it can shoot. An arrow must "flex" a little bit to both absorb the bowstring's energy transfer (from the bowstave) and to curve around the belly of the bowstave (this is often called "The Archer's Paradox"). Too much "flex" and the arrow COULD snap/shatter upon launch. This feature of an arrow is called "spine" in arrow selection guides. Regardless of an arrow's spine, there is a standardized weight for bows based on Draw Weight. This formula is 5 grains of arrow weight per pound of bow draw weight. Most big game arrows (and war arrows) will go 10 grains per pound of draw weight. Thus a 200lb Draw Weight bow would use a 1000-grain arrow. An 80lb Compound Bow will use a 400-grain arrow for hunting.

It's obvious that Draw Weight influences damage.

Draw Length: This is the length of arrow needed to properly fire the bow (or crossbow) at the velocity listed for that weapon. The standard draw length set by international standard is 28" of length. The standard set by the US bow industry (and the stat you most commonly find on the internet) is a 30" Draw Length. Draw Length is determined by the length of your arms. For every inch you change the Draw Length, you adjust your arrow speed by 10fps. Additionally, you will lose 1.7fps for every 10 yards the arrow travels. Traditional bows (composite, long, recurve, and self bows) can use ANY length of arrow. You just won't pull the bow back to its full draw with a shorter arrow and will have too much arrow out front (which can affect its flight) for longer arrows. Compound bows are "tuned" to use a SPECIFIC arrow length. overdrawing or underdrawing a compound bow can damage it. Compound bows can be fitted with "loops" (extensions tied to the bowstring) to allow the fire of shorter arrows. This will require a mechanical release (trigger mechanism held by hand) to use though. A compound bow can use up to a 2" Loop and Mechanical Release to adjust Draw Length.

Efficiency: You will see this trait often "espoused" by manufacturers (most compound bows boast a 95% Efficiency). It is the amount of a bow's power that is transferred to the arrow upon release of the bowstring. The longer or heavier an arrow is, the higher the bow's Efficiency will be. This is because the bow string will act upon the arrow for a longer time before the arrow parts with the string. A lighter arrow will SIGNIFICANTLY INCREASE the noise a bow makes (the "shawaaack" sound you will often hear during archery). This is because the excess energy that is left in the bow is causing it to "resonate" and make that noise. String silencers can help this. Heavier arrows will make LESS NOISE when fired because they absorb more of the bow's energy before parting from the string.

Based on what Draw Length influences, I think this should figure prominently into determining Range. I also believe it should (along with cross-sectional density) affect Penetration as well.

These are some basic terms you need to understand in order to model the damage of a bow or crossbow in Twilight.

[The Dark]

There's a good article looking at energy, momentum, and sectional densities of projectiles here. Converting the foot-pounds of energy to joules:

Medium game (deer, antelope): 34 joules to 56 joules
Large game (elk, boar, black bear): 57 joules to 88 joules
Very large game (cape buffalo, grizzly): 89 joules plus

A primitive bow generates 39 joules, a modern bow 79. The light atlatl dart is 61 joules, and the heavy 84 joules. The low kinetic energy means there won't be any hydrostatic shock or penetration of modern armor, but the high momentum and sectional density suggest it should do well against soft tissue. It's one of those areas that's hard to model, particularly given T2K's reliance on KE for damage and penetration.

To give ideas of where the damage should fall, medium game has 6 hits, large game around 20 (using boar), and very large game 40-50 hits (using bear, cattle, and bison). One could argue for 2d6 for the old bow and around 6d6 for the other three weapons, since they should be able to drop boar. I'm not sure I'd go that high, but it's not totally absurd.

[swaghauler]

Obviously, Twilight2000 uses Kinetic Energy to determine damage and this has led to the "undervaluing" of projectile weapons. The principle reason for this that the devs (along with significant numbers of the shooting community) only did PART of the equation for determining damage. If one reviews the Ethical Hunting Chart I posted above (used to determine the minimum KE needed to hunt various sizes of game animal), you will see that rifle (and pistol) bullets on average, require 60 TIMES the KE to ethically harvest game that a bow or crossbow would require. Why?

Kinetic Energy's "dirty little secret":
If you increase the Velocity of an object, any other object that object contacts must DOUBLE its own resistance to the contacting object. This is part of the Law of Conservation of Momentum. So what does this mean? It means that if two objects possess the SAME KE, the HEAVIER OBJECT will take longer to decelerate. This is because the faster object is meeting more resistance and shedding speed faster than the slower but heavier object. The lighter but faster object exerts more "force" per inch traveled, but because resistance is squared, it is decelerating faster than the heavier object and therefore penetrates less.
This is why a .30-06 will stop in a dirt-filled box that an arrow will cleanly penetrate. This is the difference between Kinetic Energy (the total energy an object has) and Momentum (the energy an object "exerts" over a given time and distance).

How Cross-Sectional Density Affects Penetration:
What's the difference between a 100mph arrow and a 100mph baseball? In a word, cross-sectional density. Milano discusses this in his own firearms upload (which I HIGHLY recommend). The 5oz baseball has a CSD of 0.0014 PSI (CSD is a measure of surface pressure) while a modern 540-grain arrow (even ignoring the mechanical advantage of its cutting head) has a CSD of 0.653 PSI. An 180-grain .30-06 bullet has a CSD of 0.285 PSI. The arrow exerts 2.25 times the surface pressure that the bullet does and a whopping 466 times the pressure that the baseball does. This is why the arrow penetrates the object while the bullet stops and the baseball bounces off.

Adjusting Twilight2000 V2.2's Damage:

I would multiply a projectile weapon's KE by a modifier BEFORE doing the calculation for basic damage dice. This modifier needs to take into account the SCD of the weapon. With that in mind, here's a test sample of modifiers.

Sling Stone (with a low SCD): 10 X KE, then use the Twilight2000 Formula.
Sling Bullet (higher SCD): 20 X KE, then use the formula.
Bows, Crossbows, and Atlatls (much higher SCD): 30 X KE, then run the formula.

This should get projectile weapons closer to real-world effectiveness.

Determining Range in Twilight2000:

I would use the Bow's Design, Draw Length and SKILL Level (yes skill) to determine the base range of projectile weapons.

Bow Design: Compound, Composite, and Recurve Bows. These bows tend to have better Efficiency than Long or Self Bows. The Compound Bow does this through its Cam and Pulley System. The Composite Bow's multilayer construction increases Efficiency and the Recurve Bow's forward facing limbs use a longer "stroke" (impulse of fire) to impart more energy to an arrow. These all will help increase the Range of the arrows fired from these bows. Compound and "Reverse Arm" Crossbows would have a similar "efficiency advantage" over basic Recurved and all of these would have an advantage over basic "self-bow" crossbows.

The Base Range could be: Compound Bow - 20m, Reverse Compound Crossbow - 30m, Compound Crossbow - 25m, Composite Bow/Recurve Bow (20m for a Composite Recurve like the Mongol Bow) - 15m, Recurve Crossbow - 20m, Long Bow/Self Bow - 10m, Self Crossbow - 15m.

Draw Length: Bows (and crossbows) could be classified as Short, Medium or Long by their Draw Length. Longer Draw Lengths add velocity (at about 10fps per inch of length) which adds Range.

The Draw Length adds could be: Short Draw Length is 24" or less (bows) OR 7" or less (crossbows) - SUBTRACT 5m from Range (minimum 5m rng). Medium Draw Length will be from 25" to 29" (bows) OR 7" to 12" (crossbows) - NO ADD to Range. Long Draw Lengths will be 30" or more (bows) OR 13"+ (crossbows) - ADD 5m to Range. You MUST use the ARROW length to determine the Range Add. Shooting a 24" arrow from a 30" Recurve bow gives a 5-meter range penalty.

Skill Level: I would add the archer's Skill Level to the Base Range of the weapon. Also, remember that Commercial Compound/Recurve and Long Bows will generally have Pin Sights that make aiming easier. These bows would have an Average Skill for a Snap Shot, while more traditional (or home-made) Bows would have a Difficult Snap Shot. Slings would be a Formidable Snap Shot.

This is just my take on Bows. As always, use what you will and discard the rest.

Swag.

[The Dark]

Originally Posted by swaghauler

Adjusting Twilight2000 V2.2's Damage:

I would multiply a projectile weapon's KE by a modifier BEFORE doing the calculation for basic damage dice. This modifier needs to take into account the SCD of the weapon. With that in mind, here's a test sample of modifiers.

Sling Stone (with a low SCD): 10 X KE, then use the Twilight2000 Formula.
Sling Bullet (higher SCD): 20 X KE, then use the formula.
Bows, Crossbows, and Atlatls (much higher SCD): 30 X KE, then run the formula.

This should get projectile weapons closer to real-world effectiveness.

Using this with the World Tamer's Handbook bow construction rules, a 1.8m wooden bow becomes Dam 4, and a 1.5m composite steel bow (which requires Str 10) is Dam 6.

I don't think I'd use the range modifiers, because the ranges are already pretty long (30 meters for the wood bow and 50 meters for the composite steel). Adding modifiers will make them outrange rifles; to me, that's undesirable. Of course, as always, each campaign can judge for itself.

[.45cultist]

Originally Posted by The Dark

Using this with the World Tamer's Handbook bow construction rules, a 1.8m wooden bow becomes Dam 4, and a 1.5m composite steel bow (which requires Str 10) is Dam 6.

I don't think I'd use the range modifiers, because the ranges are already pretty long (30 meters for the wood bow and 50 meters for the composite steel). Adding modifiers will make them outrange rifles; to me, that's undesirable. Of course, as always, each campaign can judge for itself.

I'm looking at the copy I bought from DriveThru now. Between the museums and pattern rooms and the primative and BP shooting clubs, my "Home Front" notes are going to get more stuff. Liberty Missouri has a "suttler" store with pictures of some clubs, including a German one that bought some of their partisan shirts. Bows backed by BP revolvers could give a nasty shock to a brigand band.

[swaghauler]

Originally Posted by The Dark

Using this with the World Tamer's Handbook bow construction rules, a 1.8m wooden bow becomes Dam 4, and a 1.5m composite steel bow (which requires Str 10) is Dam 6.

I don't think I'd use the range modifiers, because the ranges are already pretty long (30 meters for the wood bow and 50 meters for the composite steel). Adding modifiers will make them outrange rifles; to me, that's undesirable. Of course, as always, each campaign can judge for itself.

I don't have the World Tamer's Handbook (I only have FF&S and the Small Arms Guides in both versions) so I have no idea how it figures range. I guess I'll have to get the PDF now. The ranges I was postulating were Base Ranges that were modified NOT adds to the WTH modifications. This is because my primary source, The Small Arms Guide, doesn't even list a method of determining Range other than "comparative analysis" of weapons that are already in the guide. I can see your confusion, though, because there were a few "typos" in both posts that I had to correct.

I'm still not sold on how the WTH calculates range based on bow size. This is because a Mongol Composite Bow with a draw length of 26" and an English Yew Longbow with a draw length of 30" can both have the same "Draw Weight." They would be shooting the same weight of arrow and have roughly the same maximum range. This is because the shorter but thicker/higher density for its length Mongol arrow would be less affected by drag (because of its shorter length) while the Longbow arrow would suffer more drag because of its 4" longer length. The Longbow arrow would have launched at about 40 fps faster than the shorter Mongol arrow so both would travel about the same distance. Up close, the Longbow would shoot MUCH flatter than the Mongol Bow and would have a longer "point blank range" (the distance where elevation is NOT needed to hit a target) than the Mongol Bow. One must also consider that most bows shooting arrows of standard weight (between 5 and 10 grains per pound of Draw Weight) will have lost between 40% and 50% of their Kinetic Energy at 100 meters.


I have been giving my initial thoughts on Range some more consideration today and I would offer an alternate take on determining range "comparatively" (a la Small Arms Guide) based on the following characteristics.

1) Draw Weight. I'm using the STR of the Bow based on dividing a bow's draw weight by 20. to determine the Range Bonus, just add STR in METERS to the bow's base range. An 80lb Compound Bow would add 4 meters to its Base Range for draw weight. Crossbows require 1 STR per 50 pounds of Draw Weight.

2) Efficiency. After doing a little research during my lunch break today, I found out that Efficiency varies by more than I originally thought. Those folding "survival bows," the homemade PVC bows being made and shot on Youtube, and several cheap fiberglass or plastic bows all have Efficiencies below 80%. This means that a 40lb PVC bow will only impart 32lbs of force to the arrow. This reduces the arrow's Kinetic Energy significantly. Most modern, professionally made bows, regardless of what they are constructed from, will have Efficiencies at or above 90% (with many being 95%). I figure the best way to model this would be to... DEDUCT 5 meters for Efficiencies below 80% and ADD 5 meters for Efficiencies above 90%. Efficiencies between 80% and 90% would make NO CHANGE to the bow's Base Range. The Base Range CANNOT be reduced below 5m by poor Efficiency.

3) Draw Length. The longer the length of draw that a bow has, the longer the string acts to transfer energy from the bow. This is a measurable 10 fps per added inch of travel. Thus Draw Length has a large impact on Range because a faster arrow just "shoots flatter" (giving a better "point blank" range for that bow). Lighter arrows like Turkish "Flight Arrows" can also improve range but this is a "fine line" because lighter arrows are more affected by wind and drag. This is why hunters of larger game (at longer ranges) and warriors prefer heavier arrows. Their momentum is less affected by the environment (even if one must aim a little higher to account for their increased drop at range). I like the idea of adding 1 meter for every inch of Draw Length over 29" (13" for Crossbows) and subtracting 1 meter for every inch below 25" (7" for Crossbows) of Draw Length.

4) Bow Type. Differing bow types have different efficiencies and power levels based on the manner of their construction. Keep in mind that the type of construction used in a bow has NOTHING to do with Draw Weight. A self-bow could have a 200lb Draw Weight despite its simple construction (relying on the material to withstand the force like a Yew Longbow does). These types are:

The Self-Bow: The most basic bow type. This bow is made of one material and forms a "D" when drawn. This Bow is the type made when crafting a bow in a "survival situation." I would give this Bow a 5-meter base range (10 meters for Crossbows).

The Composite Bow: This more advanced bow is made from a combination of materials such as bone and wood. It can hold more power than the Self-Bow and has better Efficiency. I would give the Composite Bow a base range of 10 meters (15 meters for Crossbows). This bow type can be combined with the Recurve Bow below, in that instance, you can increase the Composite Recurve Bow's Base Range to 15 meters (20 meters for Crossbows).

The Recurve Bow: This bow has the limbs of the bowstave bent forward. This increases the amount of time the string imparts energy to the arrow (by increasing the bow's "impulse of fire") increasing energy transfer (efficiency) and (slightly) the length of draw. I give the Recurve Bow a Base Range of 10 meters (Crossbows get 15 meters). Composite Recurve Bows have a Base Range of 15 meters (20 meters for Crossbows...see above).

The Compound Bow: Most Compound bows use a cam and pulley system to increase both power and efficiency. Compound Bows have a series of features NOT shared by other bows. They are;
1. A Pin Sight (see below).
2. A "Letoff" that allows you to hold the bow steady to take aim on a target.
3. A fixed Draw Length that can only be adjusted by a Boyer (and by only 1") or requiring the user to use an extension and release.
4. The ability to adjust Draw Weight by up to 10 pounds.
I give the Compound Bow a Base Range of 15 meters (Crossbow's get 20 meters).

5) Sights on Modern Bows. Modern bows are often equipped with PIN Sights that let you zero a given arrow weight for up to 3 or 4 different ranges, based on the quality of the bow. I allow these sights to add 5 meters to the bow's (or Crossbow's) Base Range.


Difficulty Levels for Bows. A Compound Bow and any Modern Bows equipped with Pin Sights allows you to precisely aim to a point. This gives these Bows an AVERAGE Snap Shot. Traditional Bows have no aiming index so they are a DIFFICULT Snap Shot Chance. Truly difficult projectile weapons like Slings would be a FORMIDABLE Snap Shot. I will allow a "Point Blank" Range band for bows like I do for firearms. This is equal to the shooter's Skill Level in meters (note. you use the RAW Skill NOT the Asset here). If this is longer than the bow's Base Range, that's ok. The other Range Bands are STILL figured from the bow's Base Range (NOT the shooter's Skill Level).

So, if your Army Ranger decided to take up Archery in order to "silence" sentries at long range, we can now calculate his bow's Base Range:

Compound Bow (with Pin Sight and Quiver attached). 15 meters + 5m (sight) + 5m (95% Efficiency) + 4m (Draw STR) = 29m Base Range with an Average Snap Shot.

If he picks up a "home-made" 40lb Self Bow, his Base Range would be:

Self Bow. 5 meters - 5m (Efficiency) + 2m (Draw STR) = 5m Base Range (see Efficiency above) with a Difficult Snap Shot. A major step down in range and accuracy.

as always, use what you will and ignore the rest.

Swag.

[swaghauler]

Other projectile weapons need to be discussed as well. Here is my idea for determining the Base Ranges of other projectile weapons in the game. Keep in mind that these ranges are based on hitting an 8" circle. This is the standard for hunting and shooting sports. It represents the "vital zone" of most animal's torso's (including Humans) as well as a "head shot" on larger game.

The Sling:

Slings are very difficult to use having a FORMIDABLE Snap Shot. The Base Range of a Sling for hitting game/moving targets (as opposed to throwing into a mass of enemy soldiers) is 5 meters for a Sling STONE. A Sling BULLET (usually cast from lead) has a Base Range of 10 meters. The Character adds the TOTAL of STR and AGL in meters to this. A perfectly average character with characteristics of 5 would add 10 meters to his Sling's Base Range.

The Atlatl:

The Atlatl is a projectile weapon and DOUBLES Range (thrown weapons ADD Range in my game) just like other projectile weapons. The average hunter will harvest game at around 20 meters using an Atlatl but their ranges can be significantly more against stationary targets. The problem is that an Atlatl requires a LARGE arm movement to launch which will "alert" wary game. This limits the range to avoid the target "dodging" the incoming dart. The Atlatl CAN kill even large animals if it connects. I'm thinking that the Base Range of an Atlatl will be 2 X STR + AGL This means that an average character with characteristics of 5 would have a Base Range of 15 meters (giving a 30m Medium, 60m Long, and 120m Extreme Range). The chance to hit with an Atlatl is AVERAGE.

The Blowgun:

The Blowgun would use CON to determine Base Range in meters. It's Snap Shot accuracy is DIFFICULT.

Point Blank Range:

A projectile weapon's Point Blank Range is the shooter's Skill Level in meters. If the weapon's PB Range (as determined by Skill Level) is longer than the original Base Range, use it anyway. All other Range Bands are STILL figured from the original Base Range. A Point Blank shot is one Difficulty Level EASIER than the weapon's base Difficulty (ie. firing a Traditional Bow at PB is an AVERAGE not a DIFFICULT Skill check).

This is what I'm thinking for these weapons. Any thoughts would be appreciated.

Swag.

[The Dark]

Originally Posted by .45cultist

Has anyone looked at the Challenge No. 66 article "Yearning for Antiquity"?

Yes, and they seem slightly underpowered; the Heavy Self Bow is noted as a 45-60 pound draw. That's legal for hunting deer and will reliably take them down, but Game has 6 hits and the HSB does 1d6+1 damage, so it only has a 33% chance of cleanly killing a deer. Such a bow would likely be 2d6 in my modified system, and have a 72% chance of taking down a deer with one hit.

Originally Posted by unkated

(Typical) English Longbow (ca. 1300) shooting 58 gm arrow
600 fps
Dmg: 2
Pen: 1-Nil

Speed is far too high. With a 900 grain (58.3 gram) arrow from a 120-pound draw longbow, velocity will be around 175 fps. Damage using the Infantry Weapons of the World formula will be 0.44. The highest velocity I've seen for a reproduction bow is from an experiment with Turkish bows, where a 125-pound draw composite bow with a 13 gram arrow hit 357 feet per second; this bow would be Dam 0.42. The gun formula does not work for bows.