Cannons in Chainmail

Continuing our discussion of siege weapons in the original Chainmail game (the last post concerning catapult fire), and keeping in mind how these mechanics formed the basis for fireball and lightning bolt and other spells and abilities. Today we'll look at the cannon rules.

Three classifications of Cannon are Considered. They are:

Light field guns - 30" range
Heavy field guns - 36" range
Bombards* - 42" range

*These weapons are usually used only in sieges.

Rate of Fire: Treat the same as Catapults.

Arc of Fire: Treat the same as Catapults.

Indirect Fire: Indirect fire is permitted only for Bombards.

Cover: Cannon fire into woods is not permitted. Far the effect of cannon fire on specific targets of wood or stone, see the section entitled SIEGES.

Method of Fire: Fire is in a straight line to a target specified by the player firing. (Exception is the Bombard, see the rule below.) A wooden dowel is placed at the muzzle of the cannon, and a 6" "variation measure" is placed at the other end of it (the target end). At this time the end must pass directly over, rest on, or point to the specified target. The center of the variation measure is placed at the far end of the firing dowel. The variation measure is marked off in 1½" segments and numbered from 1-6 as illustrated below:

A die is rolled by the player firing the cannon, and the end of the dowel is then moved to the number on the variation measure which corresponds to the number rolled on the die. This procedure represents the variation in cannon balls, irregular gun barrels, and windage. The Dowel: The length of a firing dowel will correspond to the maximum range of the cannon which it represents. Each is colored alternately white and black to represent the flight and bounces of a cannon ball. BEFORE PLACING THE DOWEL THE PLAYER FIRING MUST STATE WHETHER HE IS FIRING SHORT (white) OR LONG (black) AT THE TARGET. All figures that are touched by the named color on the dowell [sic] are eliminated. The color sections of the dowel, reading from muzzle to roll, are:

Any terrain features which interpose with ANY section of the dowel stop the flight of the cannon ball at that paint. These terrain features include high ground, barricades made of substantial material (wood planks or stone), trees, etc. Objects the height of a man will stop the flight of the cannon ball if they are substantial and fall within the color section named for hits. A body of water will likewise stop the flight of the cannon ball if it is passed over by a section of the dowel colored the color named for hits, other than the first such colored section which represents the cannon ball in level flight, not bouncing.

Bombards: Although the size and weight of a Bombard is such that the usefulness is restricted to sieges, occassional [sic] inclusion of a Bombard might add something to your wargame. The Bombard can be fired as either a Cannon or indirectly as if it were a Catapult. If it is fired indirect a triangulation must be made just as if it were a Catapult, and in addition the variation measure is used when the line of flight is generally determined. There is no flight-bounce-roll, for the Bombard fires an explosive shell. Use a 3½" diameter circle "hit area" marker when the place the shell hits is finally determined.

Example of Firing: A player decides to fire a Heavy Field Gun at the exact center of an advancing enemy pike square. The target is close, so the player elects to call WHITE. He places the dowel, lays the variation measure at its end, and rolls the die. The number rolled is 4, so the shot goes straight. The target is 26" distant and 8" deep, so the full 3" of the second white section, and the full 1" of the third section, fall upon it. All figures touched by the white sections of the dowel (including figures not named as the target -- even friendly troops) are removed as casualties. [CM, p. 13-14]
Got all that? So basically a cannon is fired at a certain target unit (unlike catapults in which you declare (x, y) distances in inches for the shot), and you're tracking the bounce of a cannonball, creating certain "fields" where death is caused (2-3 fields decreasing from 16" to 1" in length). There is always a variation die in this play, with 3-4 indicating on target, or otherwise moving the fields a few inches short or long (as opposed to catapult fire, for which variation is optional). Again, any target figure the fields touch is eliminated (note: cannons are not mentioned in the Fantasy Supplement, and thus no fantasy types are given any immunity to that effect).

Note a possibly important distinction between catapults and cannons: the former are Indirect fire (i.e., can be arced up over obstacles), while the latter are not (explicitly blocked by high ground, strong barricades, and trees). If these rules were applied the same way to fireballs and lightning bolts (respectively), then we would have some interesting repercussions, especially in the underground setting. Other questions and comments, as before:

First: Is this 1:1 or 1:20 scale for the cannons? As we saw for catapults, there are several compelling reasons why this whole section might be considered "misplaced", and that it would fit better in the Siege section, which is at man-to-man (1:1) scale. Again we can look at the singular language involved ("bounces of a cannon ball"), and the irrationality of having a battery of 20 cannons with assumed "variation in cannon balls, irregular gun barrels", etc., all firing and bouncing at exactly the same distance. Even though you've got language for Bombards specially restricting those to sieges, I think the whole section would be better understood if moved to the Siege/Man-to-Man section.

Secondly: Is the area of effect reasonable? Take the white hit area for the light field gun, a total of 19" long. This is some 19/0.5625 = 33.8 standard figures deep (if at 1:20 scale, killing 676 men). Or double that if you allow the listed width (5/8") to contact 2 figures on each side (over 1200 men?) And this from apparently one single cannonball. Or think of it this way (again at 1:20 scale): the standard figure presents a front scale 22.5 feet across (3/4 inch/fig × 10 yards/inch × 3 feet/yard); I like to think of that as about 7 men across in formation; and yet the single cannonball kills every man across this field over 20-feet wide. I don't think that's reasonable.

Thirdly: Is the method of fire reasonable? Catapults are entirely based on player skill (with its distance-declaration mechanic), but cannons have a much simpler targeting mechanic to apply (declare an enemy unit, instead of a location). This is probably more like what we're familiar with in D&D itself. There's mandatory range variation (2/3 chance to modify by 1.5 or 3"), although it is less than the catapult optional rule (up to 6" in either direction). I think that's pretty reasonable, pardoning the expectation for bouncing cannonballs and the need for several specially-marked dowels. (Caution: I haven't ever playtested this.)

One other thing that catches my eye: the "Example of Firing" indicates a target that by my standards would be a huge unit! "An advancing enemy pike square... 8" deep". So if that's literally a square 8" on a side, that's 8/(3/4) = 10.67 normal man-sized figures, or something like 100 to 120 miniatures on the table just for that unit (2,000 to 2,400 individual men?). Maybe I'm playing with Lilliputian-sized units in my wargaming, but that seems really enormous. Although if that actually was the standard at the time, then it would at least partly mitigate the difficulty of directing range declarations onto a given target for catapult fire, etc. (as mentioned last time). See also Swords & Spells, which specifies some large minimum figure counts for certain formations ("Mass means a formation of troops at least 15 figures across and six ranks deep... Column Mass is a formation at least ten figures across and eight ranks deep..." [S&S, p. 6]).

(Photo by GraphicReality under CC2.)


  1. I think you have misinterpreted the variation dowel -- although not explicitly stated, it should be placed *perpendicular* to the firing dowel. One clue to this is in the firing example: The number rolled is 4, so the shot goes *straight*.
    This was apparently pretty common in Napoleonic wargaming. I am including a link to a PDF of Strategy & Tactics Magazine Vol. II no. 2 (#12 overall) from 1968, which has an article by Ray Johnson on page 6 that makes this clear.
    I leave it to your estimable judgment how this will affect your thoughts on lightning bolts, etc. Keep up the great work!

    1. Wow, what an interesting observation! It's serendipitous, because I was just finally reading Gygax & Arneson's rules for Don't Give Up the Ship!, and I was surprised to see that variation in mortar shots there (p. 27) used two rulers, one for parallel variation and for perpendicular (and quite elegant; put the "7"'s on the target, roll 2d6 per direction, that's where the shell lands).

      So it's strange that here they reduced it to one direction -- with the catapult variation being only parallel, the cannons only perpendicular (if your reading is right). I agree that the "so the shot goes straight" in the example is highly suggestive, although it's to see how one would be tricked extrapolating from the prior catapult example (which very straightforwardly parallel variation only).

      Thanks for pointing that out!

    2. Woooow that placing makes so much more sense! Thanks for pointing that out. xD