The penetration values on the Gun charts were created by fitting an equation for armor penetration developed in 1939 for U.S. Naval Guns. There are several parameters controlling this equation: muzzle velocity, shell weight, gun caliber, and a frictional factor reflecting the slowdown of the shell as it travels through the air. A nonlinear equation fitter was used to optimize the unknown factors for each ammo type to the known penetration values from well-respected references.

The numbers on the penetration charts are a little more complicated. Each vehicle is modeled as a set of armored areas, such as "mantlet", "upper hull", "glacis", "suspension side" etc., each with a cross-sectional area, an armor thickness, and an armor angle. The chance of hitting each area is computed based on the target aspect, and the effective armor is computed from the armor thickness, angle, and aspect. For each penetration value, the chance of hitting an area that can be penetrated is computed. Finally, since shell penetration can vary due to a variety of factors, the penetration value is "varied" somewhat up and down and the numbers are recomputed and blended together to form a final set of numbers. The hull-down numbers depend on the maximum depression of the gun and whether the vehicle has a turret.

German, Japanese, French, and Italian Artillery

The Germans, as well as several other nations, used a method derived from World War I methods and limited by their lack of radios. The artillery battery sets up in a fairly safe place such as behind a woods. The forward observer moves forward a distance, stringing field telephone wire between the battery and his Observation Post (OP). When he gets there the distance and angle to the battery are carefully measured. When the observer sees a target of opportunity, he rings up the battery's fire control and gives them an estimate of the range and angle to the target from the OP. The fire control officers use logarithm tables and adding machines to do the trigonometry to convert the two angles and distances to one angle and distance, and to correct for wind, humidity, powder characteristics, etc. Each gun is adjusted to hit the same spot (a converged sheaf). Total time between first call and first firing: 12 minutes (6 turns).

Corrections of up to 400m could be done fairly quickly using some short cuts, but longer distances would require recomputing the entire fire mission.

Soviet

The Soviets had a hard time training good observers and fire control specialists. Those who could usually ended up in Artillery Divisions and will rarely be represented in the game. In the game this is reflected by the fact that all Soviet artillery except mortars and direct fire must be pre-plotted.

British

Before Dunkirk, the British used the same methods as the Germans and others. After Dunkirk, the British changed their fire control methods. By giving every FO a good map and a truck to haul a radio (and its large acid batteries), they separated the direct tie between the FO and his battery, allowing more than one battery to be called in by a single FO. More importantly, the map, which was gridded off in 1km intervals, was used directly in figuring out how to aim the guns -- a simple right-triangle calculation was all that was necessary. This process took only two minutes. They felt it more important to get the guns on target quickly than work out the perfect shot, so no time was spent in individually aiming the guns -- the sheaf was never converged. British FO's were highly trained and given great latitude in determining how much artillery was appropriate for a given target.

American

The Americans used a refined version of the British system. First, they had the industrial capacity to produce and deliver tons of dry cells every week, so they gave everyone a radio. So in addition to the regular FO's, any platoon-sized unit can call for artillery (though somewhat less accurately). An officer heading the American Fire Control Center sifted through all the calls for help and deciding how much to assign to each target, given the observer, the probable target, and the ammunition restrictions. Fire Control Centers used a set of clear protractors and rulers already corrected for wind, powder, etc., so converging the sheaf was possible, and the response time was very quick.

Sources on WWII Combat

Books

• Arms and Armor Press, Various Authors, Tanks Illustrated Series; Arms and Armor Press, London; 1985; including US Halftracks.
• Chamberlain, Peter; Doyle, Hilary; and Jentz, Thomas L.; Encyclopedia of German Tanks of World War Two; Arms and Armor Press, London; 1978 republished 1993.
• Forty, George; German Tanks of World War Two in Action; Blanford Press, London; 1987.
• Forty, George; M4 Sherman; Blanford Press, Poole, Dorset; 1987.
• Milsom, John, Russian Tanks 1900-1970; Galahad Books, New York, 1970.
• Myers, David; Unit Organizations of World War II; Z&M Enterprises, Milwaukee WI; 1977.
• Osprey Publishing, Various Authors; Osprey Vanguard Series; Osprey Publishing, London; 1981-1983; including Numbers 17, 20, 24, 25, 32.
• Profile Publications, Various Authors; Profile AFV Weapons; Profile Publications, Windsor, Berks., 1978; including Numbers 15, 22 and Volumes 3 and 4.
• R.A.C. Tank Museum, Fire and Movement; Royal Armoured Corps Tank Museum; Bovington Camp, Wareham, Dorset; 1975.
• Sawondy, Michael and Bracher, Ken; Maus and Other German Armored Projects; Schiffer Publishing Ltd., 1989.
• von Senger und Etterlin, Dr. F. M.; German Tanks of World War II; The Complete Illustrated History of German Fighting Vehicles 1926-1945.
• Squadron/Signal Publications, Various Authors; Squadron/Signal "In Action" Series; Squadron/Signal Publications; Carrolton, TX; 1981-1988; including Numbers 12, 16, 20, 24.
• U.S. War Department, Handbook on U.S.S.R. Military Forces, War Department Technical Manual TM30-430, November 1945.
• U.S. War Department, Handbook on German Military Forces, War Department, Technical Manual TM-E 30-431, March 1945, reprinted 1990 by Louisiana State University Press.
• Wesely, Major David A.; Lectures on Artillery; Origins '94 Game Convention, July 1994.

Miniatures Games

• Chadwick, Frank, et al.; Command Decision; Game Designer's Workshop, Bloomington, IL; 1986.
• Chadwick, Frank, et al.; Striker; Game Designer's Workshop, Bloomington, IL; 1981.
• Kelly, Michael E. and Pula, Michael S., Battalions In Crisis!; Phoenix Military Simulations, Gaithersburg, MD; 1993.
• Reynolds, David B.; The Clash of Armor; Clash of Arms Games, Phoenixville, PA; 1993.
• Stokes, Brian F.; Tank Charts; GHQ, Minneapolis, MN; 1984.

Board Games

• Avalon Hill, Squad Leader; Avalon Hill, Baltimore MD.
• Excalibur Games, Panzer; Excalibur Games, Windsor, Ontario, Canada; 1993, originally published in 1979 by Yaquinto Printing Co. Also Armor and 88 in the same series.

Advanced Rules