First change is doing away with the long, composite, and short bow paradigm of D&D. These types of bows will still exist, but they represent the actual manufacture of the device and not so much the range or damage. A composite bow will be smaller and more expensive than a normal bow (self bows) for the same draw weight. So a composite bow will be smaller and lighter than a bigger bow of the same pull, but will fit better in a dungeon.
Your character's STR value defines the maximum draw weight that can be pulled. The following table show draw weight to STR values.
| Draw-weight (lbs) | STR |
| NA | 3-6 |
| NA | 7 |
| NA | 8 |
| 30 | 9-12 |
| 40 | 13 |
| 50 | 14 |
| 70 | 15 |
| 80 | 16 |
| 90 | 17 |
| 100 | 18 |
| 110 | 19 |
| 120 | 20 |
With so many variables in involved when shooting a bow and arrow it became clear early on that some serious simplification would be necessary to keep things under control. So after doing some calculations and looking up some references I came up with the bow table below that shows damage by range given a character's strength and the choice of arrow weight.
For example, my character with a 14 STR has basically two choices: a 200 grain arrow which will shoot surer or a 300 grain arrow which will hurt more. I can also equip both in the quiver so when precision is more important than damage my character can select the better of both arrows.
If my character fires the lighter 200 grain arrow the effective range given his STR is 100 yd. He gets full damage (2d6) at short range (30 yd.). At medium range (60 yd.) damage suffers a -1 penalty and at long range (100 yd.) a -2 penalty. Below the bow table is the range table. When shooting a lighter (flight) arrow my character enjoys a +2 at short range, +1 at medium and +0 at long range. The clearance row indicates how much roof clearance I need to use that range effectively and it is based on the arrow drop per range. My character can use direct fire at 30 yd. range, requires a 10 foot clearance at medium (maybe not possible in a dungeon) and high clearance (no roof, no tree line) for longer ranges.
If damage were more important I can switch over to the 300 grain arrow which has more momentum. The difference is that all ranges include a +1 to damage bonus at the expense of the to hit bonus. At short range my +2 bonus is gone, at medium range I get a -1 and a -2 at long range.
Stronger characters will be able to pull event higher draw weights and use heavier arrows more effectively. This will increase the damage deliverable by each arrow and increase the effective range of the bow. Heavier arrows will have more momentum and be effective at longer range. The downside is that they require more energy to propel and thus have higher DynE.
DynE is a value used in Era's combat mechanism and relates directly to fatigue during encounters. More of this will be covered in the next part of this series. In subsequent parts I'll go over bows for smaller humanoids (dwarf and halfling sized characters) and I'll take a look at how this relates to attacks per round.
| STR | Human 32” arrow shaft | |||||||
| light arrow | heavy arrow | Arrow Weight (grains) | 30yds | 60 yds | 100yds | 150yds | 200yds | DynE |
| 9-13 | 9-12 | 150 | 2d4+1 | 2d4 | 7 | |||
| 14 | 13 | 200 | 2d6 | 2d6-1 | 2d6-2 | 8 | ||
| 15 | 14 | 300 | 2d6+1 | 2d6 | 2d6-1 | 10 | ||
| 16-17 | 15 | 400 | 2d8 | 2d8-1 | 2d8-2 | 2d8-3 | 12 | |
| 18 | 16 | 500 | 2d8+1 | 2d8 | 2d8-1 | 2d8-2 | 14 | |
| 19 | 17 | 600 | 2d10 | 2d10-1 | 2d10-2 | 2d10-3 | 2d10-4 | 16 |
| 20 | 18 | 700 | 2d10+1 | 2d10 | 2d10-1 | 2d10-2 | 2d10-3 | 18 |
| 19 | 800 | 2d12 | 2d12-1 | 2d12-2 | 2d12-3 | 2d12-4 | 20 | |
| Range modifiers | |||||
| 30yds | 60 yds | 100yds | 150yds | 200yds | |
| light arrow | 2 | 1 | 0 | 0 | 0 |
| heavy arrow | 0 | -1 | -2 | -3 | -4 |
| clearance | direct | 10 feet | 30 feet + | 30 feet + | 30 feet + |
Image source
http://disneysrobin.blogspot.mx/2009/04/jonas-armstrong-and-his-bow.html
Reading material
English Longbow Testing against various armor
Javascript Archery Ballistics Calculator V2.08
A New Artefact Typology for the Study of Medieval Arrowheads
EXTERIOR BALLISTICS OF BOWS AND ARROWS
On the Mechanics of the Bow and Arrow
11 comments:
I'd personally multiply your draw weights by 50%. If STR 20 is close to maximum normal-human ST, than that should be close to the 180-200# bows that are historical finds from the Mary Rose. A normally strong man can probably pull a 50# bow, not even allowing for skill.
More later; I was just reacting to what I thought was a lowish estimate of draw weight. You're going to want 50-200#, more or less, from average to "about as strong a bow as we've seen pulled."
FWIW, Mark Stretton pulls at least a 180-190# English warbow.
Another point: real war arrows, historical finds from real bows presumably in the 130-180# range, were on the order of 1400 grains. These things were HEAVY, and could be projected hundreds of yards (maybe 200-250yds).
So I could start at 30 lbs for 8 STR, allowing for light bows. I've seen references to women preferring those bows. Then go up 20 lbs per step. 50 lbs for average STR 9-12 and 20 lbs steps afterwards.
70 - 13 STR
90 - 14 STR
110 - 15 STR
130 - 16 STR
150 - 17 STR
160 - 18 STR (last three steps have only 10 lbs gain).
170 - 19 STR
180 - 20 STR
In the next part I'll go over Era's weapon and armor mechanism and take a look at the probabilities of the arrow going through skin, leather, chainmail and plate at various ranges. So that might call for a bit more calibration on the damage chart. I'm considering that a character with 16 STR should be able to penetrate plate mail at short range using a heavy arrow. I'll shift weights up to consider 1400 grains as max and take 1000 grains as something that can begin to break through plate (albeit not of the best quality).
Your chart showing bows at 70-180lbs doesn't make my Sense-of-Disbelief-o-Meter twinge at all.
For the arrows-vs-plate argument, I've seen too many convincing arguments on BOTH sides to weigh in convincingly. Given your post where you do exactly what you suggest, so long as the results match your desires, there's probably published support for it somewhere. :-)
Douglas, could you point me towards any of the arguments for arrows being able to penetrate plate armor? I haven't seen any, but I have a post on this topic and would like to be able to present a balanced view if there is another side to it.
The reference material linked to in the post has some information on the penetrating power of arrows. Particularly the first link. Although I'm not entirely convinced on the numbers the practical tests do show some arrows penetrating the armor.
Ben, here are some videos showing arrows going through steel drums.
http://www.youtube.com/watch?v=yCSJCdq_fms
http://www.youtube.com/watch?v=Qc-srIw3na0
The last one shows the speed arrows went off.
I used a calculator to estimate drop and momentum. Did tables like the following going from 261 fps to 341 fps. Columns show drop in inches every 10 yards and the P values below are momentum values I used to relate momentum between different grain tables.
Once I had those values as reference the rest was trial and error until I got the response to armor I posted in the second part of the article. http://saurondor.blogspot.mx/2013/02/building-my-characters-bow-part-2-damage.html
Length 32”
Weigh 800 grains
Speed 261 281 291
0 0 0 0
10 3 2 2
20 11 9 9
30 25 22 20
40 45 39 38
50 73 64 59
60 109 94 86
70 152 131 122
80 206 175 163
90 265 229 216
100 337 291 271
261 281 291
P @ 30 yds 0.872 0.938 0.973
P @ 60 yds 0.824 0.885 0.917
P @ 100 yds 0.771 0.826 0.853
The Stretton warbow tests were found in Soar's "Secrets of the English War Bow."
I have seen the article by Matheus Bane before but had forgotten about it. His and a number of other tests have shown that arrows can penetrate the armor. I suppose it's more a matter of whether arrows can penetrate plate effectively. Bane's tests showed that the needle point bodkin penetrated 0.5", which could be a fatal wound depending on where it struck, and probably not an instant kill. This is the only somewhat reliable test I've seen to demonstrate that result. It's also worth noting that his tests were done with plate that's on the thin side for historical armor (1.2mm). I've seen other tests where the arrow penetrated, but not enough to cause serious injury.
The videos you posted aren't really relevant as far as I'm concerned. If nothing else, the arrowheads aren't historically accurate. There's also the question of the quality and thickness of the steel drums, padding, etc.
I haven't heard of the Stretton warbow tests and can't buy Soar's book right now. Any idea of there's a summary or discussion about it online somewhere?
On a forum I visit there was a discussion of this topic with some great info summarized here: http://www.codexmartialis.com/viewtopic.php?f=11&t=685
You might find some of the info on my blog useful:
http://www.benjaminrose.com/post/can-arrows-penetrate-medieval-armor/
I've linked to a few videos that are a little more historically accurate, along with some online discussions and articles you may or may not have seen before.
Here's a historical resource you might be interested in:
http://pgmagirlscouts.files.wordpress.com/2012/10/saracen_archery.pdf
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