Bows, Crossbows and Their Balance

[darktoes]

Wiki says shurikens were used mainly as a secondary weapon, either as a backup knife or to throw at people as a distraction, often with poison, or even dropped to act as caltrops. I suspect they were hugely inferior to pretty much any other weapon, especially at range.

The issue is that shurikens aren’t stabilised like a bullet. They stay flat, but don’t stay oriented forwards like a bullet. Any wind would blow them right off course and discs have a terrible habit of not flying forward in the slightest. And that all assumes that you could somehow get a crossbow to also cause a rotation during firing, which would be pretty difficult. I don’t think they would be very accurate, and they probably wouldn’t cause much damage unless you had sufficient power to actually cut into a person, which would be substantial. For fun they’re cute, but I think there’s good reasons why no modern weapon uses disc/star projectiles.

[TheZoneWizard]

Historically inaccurate. Keep in mind not everything on Wiki’s will be accurate. If you think about it a moment. Carrying a bow in ancient asian nations would have been silly at best when taking stealth and the size of their bows into consideration.

In any event. I was brainstorming and providing reference material, as you seemed a bit daunted by everyone having conflicting opinions.

You don’t have to make anything I suggest. But there is sufficient evidence to assume that a short distance of 15 feet would be accurate enough to cause damage for a disc based weapon.

Like a slingshot and the guided line down the tube(instead of a trough) would be enough to send a disc with damaging force.

Also, these 2 guys play with thinner than I am suggesting and works really well as middle of the video shown. Ignore that loose slingshot. My sling idea isn’t as bulky and it has a shaped track to it. The cord would be small than the disc if you are concern about the disc sliding out via the cord/string guide.

See the circular shuriken for reference. see also:

Morgan dollar

For the shape and approximate weight. Cut the coin(in game mint out of scrap) and sharpen. Using your idea for the top load. Have a tube full of discs with a spring pusher to move them along. Similar to the crossbow guy reference or a shotgun. The discs would have a slide cut to match the size of the disc. Pump to chamber the next disc and the pump bevels to only allow one disc at a time. The disc slides down in the flat chamber. I use “tube” loosely as what I mean is a “tube”, shaped to the disc size with line cut along left/right sides for the cord(which is smaller) to propel the disc along. The cord wouldn’t be cut by the disc due to pushing motion instead of glide which is how a blade cuts. Also just using a tough ass cord helps.

[darktoes]

First of all, this is no longer discussing real bows/crossbows or those already in the game, so if you want to discuss this further I’d like to take it to a different thread.

Not daunted in the slightest, not sure what gave you that idea. I appreciate ideas and reference material but I fully reserve the right to shoot down what I think is a bad idea, as I’ve done.

Not sure why you think that’s historically inaccurate. If you have proof that shurikens were used effectively to kill people go ahead, but everything I look at says they weren’t. Even the video you provided calls them “A weapon of harassment”. They aren’t big enough to cut particularly deep and they aren’t accurate beyond a few metres, compared to the 50+ you can get with a good bow/crossbow. Like you said, 15 feet. Maybe halfway across a room, or the length of a large spear.

The other issue is if you use some sort of pump action to load a crossbow it will have barely any power, less than throwing something by hand. If you wanted some sort of crossbow to shoot shurikens with enough power to actually hurt something you would need to spend a significant amount of energy loading it, and suddenly the whole magazine system seems a bit useless. Something vastly oversized like a motorcycle wheel pushing sawblades MIGHT be useful against hordes simply by digging into limbs and slowing them down, but as a handheld weapon it’s just not practical for killing things.

[Vastin]

In terms of real kinetic force, a good crossbow really does hit as hard or harder than many firearms, they obviously don’t travel as fast as a bullet, but the bolts are heavy and carry a lot of kinetic energy so they hit tremendously hard.

For a very quick reference, a 9mm Parabellum round has (I believe) a weight of about 7.5g, and a nominal muzzle velocity of 380m/s - which comes to 2850 g/m/s of kinetic energy.

A modern hunting crossbow can fire a bolt of about 33g at a speed of around 106.5m/s - which comes to something on the order of 3514 g/m/s of kinetic energy.

Moreover, because the bolt is considerably heavier but has a cross section no larger than the 9mm, and pretty good aerodynamics, it can be expected to retain more of its velocity at longer range - though it will drop comparatively faster over the same distance, making it a bit trickier to aim.

So compared to the 9mm parabellum, the crossbow bolt can be expected to be a good 20-25% more lethal in terms of pure kinetic energy, and to carry that lethality out to a considerably greater range, albeit with less accuracy due to the bolt’s slower travel time and greater susceptibility to wind and drop.

The real problem with crossbows is of course their miserable reload time, the need for considerable strength and/or a specialized reloading lever system, and their sheer bulk and weight, which is considerable, though modern crossbow made of composite materials is much lighter than its medieval cousins, if still fairly bulky.

As a rule of thumb, a bow really would be better in many circumstances of battle where you expect to be fighting many targets simply due to its fire rate, and because you don’t usually need a projectile that lethal to stop someone in their tracks - unless you are fighting heavily armored or tough opponents, in which case the one much more powerful shot from a crossbow might be much more effective than trying to plink an armored target with several arrows.

[darktoes]

Sorry to burst your bubble, but you calculated momentum, not kinetic energy. Momentum is less useful. The equation for kinetic energy is T = 1/2mv^2. Which means that velocity is far more important than mass for kinetic energy. Using your numbers, that gives 541.5 Joules of energy for the 9mm, and 187.1 Joules for the crossbow. Significant difference. Also, crossbow bolts are significantly less aerodynamic than bullets, so they probably lose speed faster over time, but you would need some fairly complex equipment to test it for sure.

Modern crossbows or low poundage medieval ones can apparently be reloaded in around 10 seconds, which I’d consider pretty good. Not amazing, but decent. Certainly comparable to a bow, if inferior.

The important thing to remember is that bullets are a small round hunk of lead that (hopefully) expands in the target. Shoot something too hard or too soft and nothing happens and you deal very little damage. Arrowheads are effective because they have multiple sharp blades penetrating the body, and do an amazing job of severing arteries and nerves to cause damage.

The issue with zombies is that severing an artery or a nerve generally doesn’t kill them. I’m not sure what the requirement for “death” is for zombies in C:DDA, but neither an arrow nor a bullet is particularly likely to meet them, so liberal application is required. A crossbow is more likely to meet the requirement than a bow though, so my intention is for crossbows to become a stronger, more accurate, if slower, long-range solution. A sniper rifle to the bow’s assault rifle.

[Vastin]

Duh, you’re right. I should not go doing math at 1:30 in the morning.

Regarding what it takes to kill CDDA zombies however, there’s no indication that tjhe basic zombie is in any way more resilient or less vulnerable to physical damage than a normal human - the only physically exceptional thing about them is their ability to very slowly regenerate and eventually get back up if not ‘pulped’. They do also seem to ignore airborne toxins and gas, so I suppose they don’t have to breath, but they don’t need to be decapitated or delimbed or anything like that to render them inert.

As such I think we have to assume that any weapon effective at killing humans is similarly effective against zombies, for presumably similar reasons (excepting toxins). You can bludgeon, them, slice them, burn them, mince them - pretty much whatever would kill a human kills them too.

[Viik]

Was collecting material for a relatively simple final ballistics/armor pen model and can share some finds.
This one might be interesting for this particular discussion:
http://www.thudscave.com/npaa/articles/howhard.htm
In short, kinetic energy doesn’t provide a full picture on “how hard it hits” for projectiles, be it a bullet, an arrow, a javelin or an armor piercing 120mm cannon shell. Not a critique to anything particularly said in this discussion, just a food for thought.
I don’t know inner working of CDDA and not sure if current armor model can take into account important differences in what an arrow and a bullet do to a kevlar vest / thick hide / thin skin.
In the light of the above article, one would expect a high draw crossbow with a heavy bolt to be able to pierce zombie soldier armor way more efficiently than a lead handgun bullet.

Arrows and bolts lose velocity due to air drag slower than bullets as air drag is quadratically proportional to velocity and heavier mass of arrows and bolts makes drag effect less “effective” on them. Basically their ballistic curve is closer to idealistic Newtonian curve than that of the low caliber bullets, which curves significantly after midpoint (depends heavily on mass). What this means is that in principal you can have a situation where “damage output” over distance is more consistent for arrows and bolts compared to bullets. In practice, it would be very difficult to launch an arrow/bolt to the same distance as bullet while keeping precision somewhat useful. But in case of how side wind effects them is a completely different story as side cross-section of arrow/bolt is typically larger while density is lower compared to that of a bullet.

When it comes to damage, one thing that bullets do and slow projectiles don’t is a kinetic shock on impact. It can be more devastating in damage done to larger area. Not much applicable to dead tissue as damage is more of bruise to internal organs and soft tissue. But similar argument can be made for arrows and crossbows where localized cuts are not very likely to damage something that is already dead. I case of CDDA Zs, they are not actually dead and it’s more fair to compare them to alive humans, imho.

One of the reasons why medieval steel crossbows had a low efficiency is consideration of safety. For a higher efficiency you need a longer draw, which stresses steel and wooden parts more. In case of catastrophic failure, all that stored energy can be released in opposite direction. Using modern materials, factory manufacturing methods and machine testing, you can achieve much higher efficiency while making weapon even safer for the end user. For the same reason I woudn’t risk using any hand made gun with a caliber higher than .22. The bow on other hand, don’t have the same effect on the end user when they break as energies evolved a much smaller. But I don’t remember seeing any catastrophic weapon failure in CDDA, so this is not too relevant gameplay wise.

[Viik]

Forgot something else. There was this interesting side effect of the early handguns - when bullet left barrel it was under a lot of stress after tumbling in a barrel of a gun. Because of this, it could easier shatter on obstacle at short distance while having more penetrating potentials after flying more and loosing some speed. Most likely this wasn’t know to some plate manufacturers as they did a point blank shot test, to prove quality of their armors.
This is another difference between long draw bows and short draw crossbows. A long draw bow can spend more time accelerating arrow and projectile will have a lower stress/smaller chance to break on shot. Bolts mitigate some of this by being shorter and thicker,

[Vastin]

Regarding reload rates of bow vs. crossbow, it is true than an expert crossbow user could probably get their reload down to 10 sec or even a bit less which isn’t too shabby, and would be equivalent to a novice bow user (myself, for example) - but an expert bowman can probably get it down to around 2 sec with a full draw, and even less with weaker trick draws.

[darktoes]

As such I think we have to assume that any weapon effective at killing humans is similarly effective against zombies, for presumably similar reasons (excepting toxins).

Issue being that one of the main ways an arrow can kill is severing arteries so that the thing bleeds to death. Massively effective against humans and animals, probably not effective against something that doesn’t breathe and probably doesn’t even have blood. That said, zombies can still survive with some pretty significant trauma, so I suspect they’re more durable than humans and require special conditions to go down, like damage to heart or brain. I realise heart is somewhat contradictory to what I said earlier, but I imagine that might be one of the main Goo concentrations.

Was collecting material for a relatively simple final ballistics/armor pen model and can share some finds.
This one might be interesting for this particular discussion:

It’s an interesting read, but he’s still relying on the assumption that penetration = damage, when bullets primarily use impact shock and arrows are mainly about cutting through large areas of the target, rather than just stabbing a big hole. I don’t think he’s wrong, just that his assumption gives arrows less damage than they deserve.

Arrows and bolts lose velocity due to air drag slower than bullets as air drag is quadratically proportional to velocity and heavier mass of arrows and bolts makes drag effect less “effective” on them…

I agree, the velocity of a bullet makes it lose speed faster, but it has so much more to begin with. Even if an arrow/bolt has a smoother curve it’s still falls far shorter than a bullet’s. I don’t think you’re wrong that a arrow would have a better damage output over distance, but I think most bullets would hit with near full energy if they’re able to hit at all, while arrows would bleed energy pretty linearly.

When it comes to damage, one thing that bullets do and slow projectiles don’t is a kinetic shock on impact. It can be more devastating in damage done to larger area. Not much applicable to dead tissue as damage is more of bruise to internal organs and soft tissue. But similar argument can be made for arrows and crossbows where localized cuts are not very likely to damage something that is already dead. I case of CDDA Zs, they are not actually dead and it’s more fair to compare them to alive humans, imho.

I disagree that we can compare them to alive humans. They seem to be more robotic in nature, with specific critical points that cause them to fail. I.E You can bash it in the head 8 times and it keeps coming full force, hit once more and destroy the brain and it crumples.
That said, in the interest of everyone’s sanity I think the best way to compare the effective damage of weapons for the game is their use in real life/on living targets.

One of the reasons why medieval steel crossbows had a low efficiency is consideration of safety.

Heh, depends on who the person using the crossbow is. OSHA wasn’t really a big deal for peasants.
I agree, but I don’t think that’s the only factor. Things like the reliability, size, weight, all would have come into play. A small, high-poundage crossbow is probably far easier and cheaper to make than a large medium-poundage one.

Regarding reload rates of bow vs. crossbow, it is true than an expert crossbow user could probably get their reload down to 10 sec or even a bit less which isn’t too shabby, and would be equivalent to a novice bow user (myself, for example) - but an expert bowman can probably get it down to around 2 sec with a full draw, and even less with weaker trick draws.

Depends. Someone who trained all their life to use a specific bow like medieval English longbow archers could probably manage that, although I’d expect more like 3-4 seconds, but that was mainly for volley fire. If you’re trying to hit something specific at a decent distance you would need a few more seconds to aim properly. Also modern, especially compound, bows take significantly longer because of their complexity.
Trick draws would probably be borderline useless in combat, and you still need to nock the arrow which probably takes at least as much time as drawing.

[kevin.granade]

there’s no indication that tjhe basic zombie is in any way more resilient or less vulnerable to physical damage than a normal human

If you check the stats this is obviously true, a vanilla zombie has far fewer HP than a vanilla PC. Should this be the case? maybe, maybe not.

Another thing to check is spawn a NPC and plink them with a crossbow, even on a direct hit they’re not likely to drop or even slow down much. That’s pretty anti-realistic, but reversing it to “any modern weapon will drop an unarmored human with one shot” is not likely to be well-recieved, especially with the existence of automated gun turrets. Maybe we’ll go in that direction at some point by buffing modern weapons (i.e. both firearms and arrows inflict lethal and shock-inducing wounds with a single shot and MUST be tanked with body armor), but I have no intention of doing so in the immediate future.

[Tad]

Just listen here a minute. This is just my 2 cents, but I’m a hunter, don’t take my word as gold I guess, but just be aware that sometimes energy means fuck all when it comes down to killing things.

Anyone who is considering Joules or energy at all as mattering when it comes to killing things or dealing damage, is seriously not in the right mindset when it comes to reality.

A 90 J hit with a broad-head arrow will absolutely eviscerate a 160 lb whitetail deer and have it running dead for about 40 meters and it’ll drop like a brick shit house in an earthquake. A 9mm bullet (regardless of construction, JHP or bonded or whatever), in the same spot (torso/vitals area) as the previously mentioned 90 J striking broad-head arrow is far less likely to kill or even seriously injure the deer, even though that 9mm bullet as mentioned has many, many times more energy than the broad-head. Yes, striking velocity and all that aside, it doesn’t really matter when in comes to broad-heads and bows; they don’t crush tissue like bullets do they cut tissue.

Hopefully someone can extrapolate what I’ve said into something useful.

[darktoes]

That’s pretty anti-realistic,

Yep. Main issue is that baseline health is 100 hp, which humans ingame have for each body part and can tank massive amounts of damage by not getting hit somewhere vital. It’s really weird, and makes comparison difficult because humans are magnitudes more durable than zombies.

Anyone who is considering Joules or energy at all as mattering when it comes to killing things or dealing damage, is seriously not in the right mindset when it comes to reality.

That’s what I’ve been saying pretty much the entire time with regards to arrows/bolts. Well. Impact energy matters a lot for bullets, momentum matters a lot for piercing projectiles like spears and bodkins, but not for broadhead arrows.

[Tad]

Let me put it this way: It’s about drag ratios and sectional density. I find it really relatable to gurney velocities and comparing those with various fragment sizes and masses. I’ll explain what I mean, hopefully this makes sense:

Big, wide fragments that don’t have much sectional density have a lot of drag not only through the air, but in other mediums as well such as in the body, so they lose velocity rapidly and don’t go deep unless they have such a large mass that it overcomes the drag factors and velocity loss as it travels through the body/mediums.

It’s the same with bullets. Long, narrow bullets (provided the yawing remains somewhat consistent between bullets) will go deeper than bullets that are wide and shallow in length. Sectional density is key, not so much velocity or energy. They are crushing, rather than primarily cutting, tissue.

Arrows (broad heads, expanding blades, whatever) go through tissue much easier because they’re cutting and tend to have less drag, they’re not so much crushing tissue as they are cutting through it, and as for the case of bodkins well, they’re pretty much just pushing tissue aside if I’m being quite honest, Lol. That’s why they go so deep.

I’m preachin’ to the choir here, aren’t I?

[darktoes]

Yeah I get what you’re saying. Not sure if you’re fully accounting for all the variables, but the general sentiment is correct. Bullets kill by essentially causing blunt force trauma to internal organs and/or fragmenting internally and causing lots of small holes through a person, basically pulping them. Arrows are basically stabbing someone from far away. Doesn’t have all the fancy internal trauma but if you nick an artery they’re still pretty fucked.

Still not convinced that zombies have blood in their arteries to bleed out, but eh. Still a lotta damage.

[kevin.granade]

I’m preachin’ to the choir here, aren’t I?

Pretty much, broadheads need enough momentum to slice through the skin/hide, subcutaneous layer, nonessential muscle and reach internals. Excess momentum isn’t going to cause more damage, and the “exchange rate” between momentum and penetration is very good for thin, sharp arrows.

The only places where there’s a significant problem is exceptionally tough hide and thick muscles.

[darktoes]

Almost sounds like there should be diminishing returns on damage, but increased armor pierce for high end bows/crossbows.

Also, if anyone missed it on Discord I’ve been mulling over the idea of individual poundage mods for bows. My current idea is to have a set of bow types, straight bow, composite bow, reflex/recurve, modern recurve, modern hybrid, etc. Those would be the hard to build part, but only have small damage/pierce/range/dispersion stats.
From there, various poundage gunmods could be made more or less freely and instantly, and do nothing on their own, but can be put on a bow to make it whatever poundage you want, and can’t be removed once installed. Probably 10-100 in 10 lb increments, then maybe a 130 and 160. All with long and short variants for faster or more powerful variations.
Each would require more strength and time to reload, but would have higher damage/pierce and lower dispersion. That way pretty much any character can make a bow that fits them (could even do away with the current wooden greatbow and replace it with super high poundage limbs). Same could be done for crossbows.

There is also the possibility of having the poundage limbs be actual items that require material, tools and effort to acquire and are interchangeable for the most part, but that could get complicated really fast. I’m also not sure how this would work for found bows. Is it possible to set it so found items have a specific gunmod attached but crafted ones don’t?

The main issues I see are:

1. It’s not that much simpler than just making all bows in various poundages, but, depending on the complexity of the implementation, should result in far less actual new items.
2. It’s a bit strange, and there’s no precedence for this sort of thing anywhere else in the game.
3. People might miss that their bow needs a poundage and start wondering why their bow suddenly does no damage and/or won’t shoot if they don’t read the bow description.
4. It’s going to make things pretty weird later on if I (or someone else) decides to set things up differently, and I have to set up obsolete-ing code for a whole bunch of stuff.

Follow-up question, how modular would people enjoy this? There is the possibility of making all bows entirely modular, that you can make risers, limbs, strings, etc. and stick it all together however you please. It would be pretty neat and wouldn’t even be that much effort, but it would require some minor suspension of disbelief.

[kevin.granade]

Almost sounds like there should be diminishing returns on damage, but increased armor pierce for high end bows/crossbows.

Ideally we’d track overpenetration for all ranged weapons, possibly with some kind of limb model for monsters that determines thickniss at the impact site (i.e an arm hit only has a few inches to penetrate, but a chest shot has upwards of a foot depending on the target),

I’m not particularly excited about the poundage thing, in addition to the shortcomings you outline, I don’t see any precedent for it in real archery, and the number of items isn’t really an issue, especially if they’re generally crafted by the player.

[darktoes]

I’m not particularly excited about the poundage thing, in addition to the shortcomings you outline, I don’t see any precedent for it in real archery,

Well the precedent is basically that you can get a bow in pretty much any poundage you like, regardless of the type or size. It’s not like all longbows are 50lb, all reflex bows are 40lb, etc. Some bows, mainly modern recurves, are even made with the limbs easy to detach so you can swap/store them.

The first method I outlined (free to make, irremovable) is basically a tricksy way of asking the player what poundage they want a bow to be when they make it. It has some minor weirdness, but basically only that there’s a finishing step to it than can be done at any time rather than on actual completion of the item.
The second method (expensive but swappable) is generally less painful for players, and means less weirdness with spawned bows, but means a lot more work for me. Plus, bows that aren’t going to have removable limbs anyway (anything that isn’t modern) will have to be irremovable anyway and have the same issue.

It’s possible that just hardcoding a tag for asking the player what poundage they want and then automagically attaching the right gunmod for that poundage would be better for players, but it also means hardcoding which I probably can’t do.

the number of items isn’t really an issue, especially if they’re generally crafted by the player.

I’m not saying it’s going to drop our FPS 30% or anything, just that I’d like to avoid dropping 30-odd new gunmods into the crafting interface, and it makes it more painful for me having to stare at them all for hours on end in the JSON. Also I’m lazy.

[kevin.granade]

Well the precedent is basically that you can get a bow in pretty much any poundage you like, regardless of the type or size.

That’s not a precedent for it being swappable, just for different poundage bows existing.

just that I’d like to avoid dropping 30-odd new gunmods into the crafting interface,

If you think 30-something items is called for, add it, making the items act nonsensically isn’t a reasonable answer.

and it makes it more painful for me having to stare at them all for hours on end in the JSON.

Figure out how to make it not require that then.