Saturday Q&A (dec 23)

The following is presented in the spirit of rethinking and potentially improving existing rules in D&D, which is accomplished through proposing rules, describing them to the players (and others) and then playtesting those rules to see what game effects are discovered.

Sterling in Maine writes,

With my [efforts] on the missile fire rules, I was aiming (sorry) to hit (sorry, again) the apparent size of target for which the by-the-book range penalties of -2 and -5 should be applied. I used the results from the Great Britain's National Clout Archery Championship results this year and a Yorkshire regional championship of western archery results as a basis. While that part was sort of rigorous, I failed to really connect it with AD&D's combat rules which account for armor penetration and hitting moving targets. The shortcoming became painfully obvious when I began trying to actually use these rules, so I've taken another pass.

To set the context for these rules, I'd like to explain that my group plays a modified version of AD&D. We began play a few months ago using by-the-book rules with only four exceptions:

• A replacement rule for "Player Character Non-Professional Skills" on DMG p. 12

• Use of use the male values for ability score minimums and maximums on PH pp. 9 & 15 regardless of sex

• Omission of alignment

• A slightly modified starting hit points scheme: 1d6 + constitution modifier + either the maximum normal hit point roll minus 6 or zero, whichever is greater

Over time we propose rules changes and if we achieve consensus on the change, we adopt it. If you're curious, you can check out the rules we have so far proposed, some of which have been "ratified" and some are still in progress, here https://erin1478.blogspot.com/. I have been bothered by the fact that target size is not a factor in missile fire attack modifiers, and questioned the veracity of the missile fire rules generally. A few weeks ago I tried to address it, but when I tested my proposal it kind of fell apart. I've made a second pass with which I'm much more pleased and would like to share it in case it has any value for others.

It should also be noted that we have adopted 1" = 22' for distances both indoors and out instead of AD&D's 1" = 10' inside and 1" = 30' outside. There are vertical clearance rules around missile fire as well which are not addressed below, as this is exclusively about range adjustments, but which I bring up as it's mentioned by Gygax in his justification for differing indoor and outdoor scales.

The following is the proposal I sent to my players earlier this week with a little more explanation added and a couple of errors fixed:

With my previous iteration on the missile fire rules, I was aiming (sorry) to hit (sorry, again) the apparent size of target for which the by-the-book range penalties of -2 and -5 should be applied. I used the results from the Great Britain's National Clout Archery Championship results this year and a Yorkshire regional championship of western archery results as a basis. While that part was sort of rigorous, I failed to really connect it with AD&D's combat rules which account for armor penetration and hitting moving targets. The shortcoming became painfully obvious when I began trying to actually use these rules, so I've taken another pass.

This time, I'm using the same data that I had from those actual archery contests, but counted the targets as being equivalent to an armor class 10 target (no armor to penetrate) and immobile, giving the attacker a +4 to hit. To relate it to the attack matrices, however I had to equate these real-world, champion archers to a class and level in the game. I chose 7th level fighter as representative of competitors at this level. This is of course arbitrary, but I comfort myself with knowing that there is only 1 person in all of Mallow [this is the barony in which the PCs reside] with that level of archery competence and there are far more people practicing archery on a regular basis there than in modern day Yorkshire. Incidentally, the AD&D rules give a 7th level fighter the title "Champion" so that fits nicely.

For a 7th level fighter to hit the clout circle at 560' away 45% of the time, considering it an AC10 target, held immobile for a +4, the archer would need to suffer a -9 penalty. Likewise, the other rates of championship hits are equated to the penalty required to make a 7th level fighter hit that percentage of the time.

Interpolating between these values for the angular size of target which would give a 7th level fighter an attack penalty of between -18 and -8 is straightforward enough. I continued to extrapolate the angular target size implied above and below those penalties until passing the smallest angular size the human eye can perceive. The human eye can discern a minimum angular size of about 1/60 of 1 degree. Some sources report it as low as 0.01, but I've used the 0.016667 figure. In theory, that penalty is valid all the way to something as small as 0.00545 degrees to the eye, but if your eye can't see it, you can't aim for it. The -21 penalty means that a 7th level fighter needs to roll a 22 in order to hit that small an immobile target, making it just impossible. Somewhat crazily, this gives a 17th level fighter, the absolute pinnacle of AD&D combat prowess, a 45% chance to hit an immobile target just barely large enough for him to see (and within range of his weapon of course). For such a fighter proficient with and employing a composite longbow, that would be an orange at 630', 1.75 football fields away.

For penalties less than -8 and bonuses, I had to choose a maximum bonus and angular size increment. I chose to set the maximum bonus at +7 as this would give even the common man proficient with a bow an automatic hit on a stationary AC10 target. Following the same angular size increment which took the penalty down from clout circle to western target, a certain hit for the commoner must be at least 2.89454 degrees to the eye which is equivalent to a straw mannequin at 59' or a 10' by 10' barn door at 198' and is consistent with the modern recommendation for beginning archers to use an 80 to 90 cm target at 18 to 20 yards. A first level fighter who is untrained in the bow could hit it 95% of the time and an untrained commoner 75% of the time.

Interestingly, small distances close by make a significant impact; in close, a couple feet closer can improve the archer's chances by 5%, but further out distance changes mean much less. On the table below, read the rows as adjustment up to the range specified in feet for the target size in question. For other target sizes, one can calculate angular size as twice the arc-tangent of the target diameter over twice its distance away, or simply scale the distance from one of the sizes given. For example, at 70' a 3' diameter target has an angular size of 2.45006, so a 1' diameter target would have a third of that, or 0.81669 giving a -13 penalty.

In tactical unit combat, using our AD&D movement scale of 1" = 22' and a 1" marker representing a squad or more, units would be one or more rounds away and that's at least 132'. At that range the difference between missile adjustments is at least half an inch on the table, and maybe several inches. For hand-to-hand with a 1" figure or marker per combatant, a scale of 1" = 3 1/3' is necessary. In close combat on the individual scale, the increments are at least an inch and maybe as great as a 3 inches on the table.

At first I thought that this table was too granular to be practical, but I'm changing my mind the more I look at it and its implications for tactical decision-making.

What do you guys think?

_____

Thank you.

If readers would like to reply to the above, or wish to ask a question or submit observations like those above, please submit  to my email, alexiss1@telus.net.  If you could, please give the region where you're located (state, province, department, county, whatever) as it humanises your comment.

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