Responding to Comments: Heavy Bows and ST in GURPS

I got a great comment on the Bow ST thing by +Sean Powell, a fellow engineer and archery enthusiast. So I decided to make a post out of my responses to his comments. My responses to his comments will be in blue italics. His stuff is in black bold.

I’ve only been the occasional GURPS fantasy player (GURPS makes a better superheroes game IMHO and there are plenty of systems for swords and sorcery

This might be the first time I’ve ever heard of GURPS as a preferred system for supers over certainly swords and maybe sorcery!

You got the math right. (Yay math!)

After all the work on The Deadly Spring, I hope I can get E = ½ F^2/K correct. J

It’s nice seeing someone use historic data to number-crunch a game for realism. (Yay game realism!)

When I did The Deadly Spring, I researched it somewhere between quite a bit and very heavily. I read scientific papers on bow physics, at least seven or eight books on making and shooting bows of various cultures, as well as empirical trials, such as the much-loved Defense Academy Warbow Trials. I even corresponded over email with one of that study’s authors. I also paid attention – even where I thought the cases were overstated – to the many articles about armor and how it’s impervious to nuclear weapons when made by the proper medieval craftsmen.


OK, I embellish. But between the stories of bows punching through battleship belt armor and someone wearing tin foil mail being impervious to a 200-lb. warbow firing a 1,500-grain arrow, I covered the gamut of bows being the deadliest weapon to not worth using if the other guy is armored at all. I wound up striking a balance that one known armor aficionado mentioned approvingly as a good one: that a strong warbow could punch through moderate mail (DR 3-5 in GURPS terms) some of the time, but not much more. This led to the 130# longbow being pegged at about 1d+1 or so, which would make it fail vs DR 5 and higher. Plate of 1mm (DR2-3) would be vulnerable to strong bows,  but 2mm and higher would basically be nearly impervious, and certainly provide massive protection against even the strongest warbows.


In any case, the fact that we could turn Joules of energy into something that could be calibrated against firearms to some extent (take a 11.43mm bullet like a .45ACP with 475J, basically 2d penetration, and compare with an 11m arrow with 160J, and tell me how any arrow will do more than 2d penetration?) made for a nice well-supported touchstone.

I’m not a terribly strong person being a desk-jockey with arm-chair spread but it takes a fair amount of conditioning for me to maintain strength to draw my bow consistently.

The need for sport-specific exercise, as well as technique, is frequently present in the real world, but hard to model fairly in GURPS. Can be done, though, as I hope my article showed.

Very few other recreational archer I meet can consistently draw my bow even if they are very good shots with lighter bows. (They also think I’m nuts) and the ones who can already shoot ELB or self-bows.

Yeah – I’ve heard too many stories of guys that can bench press 350lbs that can’t draw a 100-lb. bow, even though ST 14 probably accounts for the ability to do both. Again: sport-specific. Pushing vs. either pulling or pull/push. I bet the archer couldn’t press 350 either. Apples and oranges.

Having read the accounts from Crece, Agincort, Poitiers and the Mary rose find along with others I don’t think that the Mary rose held an atypical selection of archers.

Me either, but the Mary Rose had a few hundred bows, and there were, what? 5,000 bowmen at Agincourt? So not truly representative. But on the other tentacle, to reach out to the 230yds that was “within bowshot” enough to be militarily significant at Agincourt, you need a strong bow. 


My spreadsheet puts a 130# bow firing a 0.2-lb arrow (about 1,500 grains) with a max range of about 245yards. A 100# bow firing an 1,150-gr arrow will reach to just shy of 230-yards. 


A 915-gr flight arrow would (by the same sheet) reach to about 265 yards, but be basically no threat to anyone on an armored region (I suspect 1d+2(0.5) would be about right for that, good for harassment but not a threat to an armored foe with more than DR 3).


Still, it supports the notion that at least a ST 14 (98-lb) bow would have been somewhere between the minimum and a decent average for the “fire at 230 yards” to have the equivalent meaning as “fire for effect.”

If the Mary Rose held typical archers and the typical archer could pull in the 160-180 lb range then we as modern men are WEAKLINGS! I only know 1 or 2 modern archers who can draw in that range consistently and they aren’t really that strong at other tasks. Meanwhile the people I know who are generally strong can span my bow a few times but not hold it without shaking and they aren’t capable of drawing the historic draw weights.

I suspect that when you have about 800,000 men available (population of England in 1400 estimated to be about 2.5 million people) getting 5,000 archers that can draw strong bows is not a problem when your national policy reflects the need. That is a very specific kind of strength, and given the “train his grandfather” trope, I suspect that kids started on light bows and drew progressively heavier ones.


The human body is very good at repetitive exercise, and this is the sort of thing that should respond well to modern training methods – if we didn’t care about skeletal deformation and out-of-balance musculo-skeletal development!

It seems the only way to draw and shoot bows in that poundage is to develop a special dedicated set of muscles (not just generally strong) and that set of dedicated muscles comes from a lifetime of bow training.

Yeah, this!


Which leaves us with: Historically the solution may be ‘trained strength’ even if that does not fit with game mechanics and game balance as easily… BUT you might consider access to certain regional/society/racial perks (Born Welsh or Raised in Mongolia)that could reduce that cost or provide a cumulative bonus if maintaining historical accuracy was very important to you.

Trained ST as it’s given in Technical Grappling and to a lesser extend in The Last Gasp is a full-body strength that is basically the ability to apply leverage, force, and weight dynamically against a resisting opponent. That’s why the +50% (ish) boost to ST requires you to get to DX+10 in order to leverage that.


Drawing a bow is not quite so dynamic. You don’t have to worry about being picked up and thrown suddenly, or doing it on the move. You set up, plunk your arrows into the earth in front of you, and fire one every ten seconds (!) in a lather, rinse, repeat motion, in order to replicate battle tactics (not FRPG fighting!) as described at Agincourt, Crecy, and the like.


As such, the Technique-based logic that makes drawing a heavy bow a matter of fairly mild point expenditure makes sense to me. The ONLY thing it applies to is . . . drawing a heavy bow. Not lifting your friends to safety, climbing walls or a rope, wrestling, or swinging a sword. Nor does it impart hit points. So if all of that is 10 points per level, then the ability to pull a bow of a given power is going to be much less than that. If you can pull a bow but not even carry heavy weights (Lifting ST at 3/level) then at the lowest you’re dealing with about 1/level (a -60% limitation on lifting ST) and at most you’re talking 2/level (-60% on Striking ST).


I like the idea of cancelling skill penalties when drawing heavy bows rather than boosts to ST, though, since it preserves the maximum amount of the RAW and tends to avoid arguments about what else ST might be good for. It’s good for one thing: cancelling penalties. This would include penalties to hold a bow at full draw, though – something that is touched on in The Deadly Spring when it comes to aiming a bow.

(This reminds me of a deleted scene in the movie Gladiator, where the Emporer is monologuing in front of a guy who he’s going to execute, all the while his archers are behind him with shaking arms and full-drawn bows, looking really panicked about it.)

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