Below is an image of a T-72 from a Steel Beasts site. It shows the different armor strengths in different areas against HEAT and KE rounds (hard to see but it’s there). I laid a gunsight over the target like I do in a regular game with the aim point being about center mass. The image shows a 39 or 40 was rolled for the D100 dispersion direction. You can see by the dispersion direction numbers around the outside of the gun sight it will generate an oval shot grouping. The red ruler is actually attached to the center of the gunsight and rotates like the hands on a clock for any 360 degree location. It is scaled to match the T-72 target. The ruler has hatch marks every 0.1 meters. You can see the exact hit location at every hash mark along the line to determine the location and armor value. It appears the dispersion from 0.0 to 0.2 will hit the upper hull and the driver. From 0.3 to 1.0 it looks like the turret but there are three different armor values along the way. From 1.1 to 1.3 it looks like some storage location. Anything over 1.3 is a miss. If the dispersion result was a 1.8, which is a miss, the next shot would use a value of 0.9 to reflect adjustments made for bracketing. It’s not historically accurate but close and seems to work. This shooting process takes about 10 seconds.

To determine accuracy mil values I use the Error Budget

system. The easiest explanation is here:

http://www.ciar.org/ttk/mbt/armor/armor-

magazine/armor-mag.2001.jf/1tankaccuracy01.pdf

I assign my variables a mil value which can scale to any range to determine a dispersion distance in meters in 100 meter increments. I’ve tried to get source documentation when I can. Not much is subjective. I like it better than basic hit numbers plus DRM’s. The targeting aspect of the game is what players seem to like the best. It gives them some control over the shot (but not much) and immediate visual feedback on the result. Near misses always draw a groan. Location hit is immediate with no modifiers needed for size or aspect or additional die rolls. In games where players can target a weak area they almost always target center mass because they are afraid of missing.

There are other ways to determine a more specific hit location without the need to use target images and use it in conjunction with the gunnery chart giving results in 0.1 meter increments. For example: The T-72 is 2.2 meters tall. That means any MPI/accuracy result of 1.1 meters or less should hit. That gives 11 different locations that could be designated as “Hit Locations” somewhat based on target area. Results of 0.1 to 0.2 could be lower hull, 0.3 to 0.5 could be upper hull, 0.6 could be tracks, 0.7 to 1.0 could be turret, 1.1 could be a roll for a special hit roll on the gun, storage area, cupola, etc. Certain values would be safe if hull down. A result over 1.1 meters is a miss. This way your hit locations could be somewhat proportional with no additional hit location die roll. Here is a quick example for one die roll to determine a hit AND location:

T-72 Hit Locations

MPI Result Location Hit Armor Strength Damage Hull Down

0.1 Left Lower Hull

Different locations can have different

armor strengths to break it down into more detail.

Ammo Yes

0.2 Treads Drive Train Yes

0.3 Right Lower hull Ammo Yes

0.4 Left Upper Hull Compartment Yes

0.5 Middle Upper Hull Driver Yes

0.6 Right Upper Hull Compartment No

0.7 Left Lower Turret Commander No

0.8 Left Upper Turret Commander No

0.9 Right Lower Turret Gunner No

1.0 Right Upper Turret Gunner No

1.1 Special hit roll on the gun, storage area, cupola, ricochet, sensors, etc

Below is part of a gunnery chart for one of my guns (I won’t say which one but I bet someone can guess). I’d suggest using 200 meter range increments for modern systems. The “Rang/Brak” row is for the first ranging shot and follow up bracketing shots that miss. Dispersion distance is randomized. All values are in meters (not mils). The first shot at a target (Ranging) takes into account the increased dispersion from a 20% unaided eyeball range estimation error. A range finder is a 10% range estimation error so would use half of the dispersion value on the first shot only. Modifiers can increase the dispersion. The chart is set up for Veteran crews. An Ace crew is -1 column, Trained crew would be a +1 column, Green crew a +3. It basically reflects their decreased ability to estimate the range correctly. Modern fire control systems would be no more than 5%.

Ranging and Bracketing shots that miss use 50% of the missed MPI value for the next shot BUT cannot be any lower than the “Ranged In” row which is the minimum dispersion once a target is hit because you have eliminated the biggest problem of shooting – correct range estimation. On the gunnery chart above at 1600 meters the gun cannot have an accuracy any better than 0.7 meters which once ranged in should give about a 60% chance of successive hits on a 2 meter high target. Penetration values are against vertical armor with no slope. The time of flight value is used to help determine lateral dispersion on moving targets as shown on the next page.

I’m doing variable armor penetration by using a chart that modifies which range column to use for penetration. Example: Using the gun chart above the APCBC round penetrates 135mm at 1100 meters. Rolling a 6 on the variable penetration chart would be a +3 modifying the penetration to the value at 1400 meters which is 125mm. The APCR Shatter Gap rules are not finished.

To the left is the armor configuration chart for the Tiger II. I’m trying to have an easy reference without using math, die rolls or computational charts to show pre-computed armor strengths on front, side and rear aspects with compound armor angles. I’ve paid particular attention to curved mantlets (not shown on this example). Vertical is 0 degrees and horizontal is 90 degrees. I rounded armor angles in 10 degree increments and armor to nearest 5 mm thickness. R = Ricochet I haven’t had anyone that is familiar with this to check it for me so any feedback is appreciated.

Firing at Moving Targets Moving Target – Lateral Dispersion: In Treadheads there are no die roll modifiers for hitting a moving target. AFTER determining the randomized MPI value and direction of the shot is determined, then determine the lateral aiming error generated by the target moving. There are three physical factors that make it more difficult to him a moving target: Target Angle in reference to the shooter, additional aiming error for engaging a moving target (a Gunner will normally be off by 33% in estimating the target speed) and the time of flight to the target. The greater the target angle the harder it is to hit, the greater the speed the harder to get the cross hairs on the target for the proper lead, the slower the round travels the longer it will take to get to the target generating a larger lateral error. This chart is designed after a formula the British used to determine the chances of hitting a moving target taking into account these three factors. This is probably the most involved mechanic in the game but does not involve any math computations. I’d like to simplify it. I added step 3 myself.

If the result of the shot is that it was over or under the target there is no need to perform this step.

Example: A target is moving at 18kph at 1200 meters with an angle off of 30 degrees. The first step is to determine the target angle to the firing unit. It can be from 10-20 degrees, 25-45 degrees or 50-90 degrees. Move down the correct column until you come to the speed of the target rounding up (18kph uses 20kph row). Then move across that row to the Time of Flight of the round (round TOF lower if target is moving towards you, up if moving away). Note the number where they intersect. In the example above we have target at 30 degrees and TOF 1.2 seconds (taken from the shooters gun chart) for a value of 1.0 for the Speed Estimation Error. Step 2 is to determine the aiming error which can increase significantly against a moving target. Find the targets speed in the “Speed Kph” (rounded up) column and go across the row to the target range (round down if moving towards, round up if moving away). With a range of 1200 meters the factor is 2.2 for the Aiming Error which is added to the 1.0 Speed Estimation Error from step one for a total of 3.2. If the target were evading it would roll a D10 x.1 and add that to the aiming error. In Step 4 it shows a 3.2 (adding values from step 1 and step 2) result rounded up. In the 3.2 column it will show what values to use depending on the shooting crews training. Now roll a D100 on the MPI Dispersion Chart (shown on next page) to determine the amount of lateral dispersion in front of (even number) or behind (odd number) that the final impact point of the round is moved.

This is a portion of the chart used to randomize the accuracy/MPI for shots and moving target lateral dispersion. The left hand column labeled % gives an approximate idea of hitting a 2m high target. The number MPI/accuracy value to randomize is in the middle/gray column. A 1.0 meter MPI with a die roll of 88 would be 1.2 meters.

Visualizing MPI Accuracy Performance This graphic and explanation will give you a better idea of what to expect in accuracy performance of a shot. You can see the best chance to hit a 2m x 2m target is to have an accuracy MPI of 1.0 or less. An MPI of 1.0 would be about a 66% chance. I tried to work it out that the lateral dispersion is no more then 1/3 of the vertical dispersion.

The image to the left gives an example of the expected average accuracy performance for different accuracy/MPI ratings against a T-34/85 with 66% of the rounds landing in the oval: A = 0.2m, B=0.3m, C=0.4m, D=0.5m, E=0.6m, F=0.7m. G=0.8m, H=0.9m, I=1.0m, J=1.2m, K=1.4m, K=1.6m

Green square = 2.0m x 2.0m

Target Aspects: Below are the five side aspects and overhead target aspects for the Tiger II. I also try to give a visual reference to the internals and systems. The armor values are shown too. This is a previous work and not current. Each image is about 6.5 x 10 inches and this is what the aiming cross hairs are used to target. They are in a booklet form that includes additional information. Dark blue is ammo storage, orange is the turret ring/gap, green drive train, light blue fuel storage. The brown square in the middle of each target is the center mass targeting area for the player to aim at.

This is the chart I use to determine penetration and damage results. I’d also like to tie it into a variable penetration too but that’s a WIP. To use the chart place a straight edge at the penetration value on the left. Align it with the armor value in the middle. The result on the right will give the penetration result and damage. I use the weight of the shell for its damage value. The damage table is not shown. APHE gives a greater chance of a fire or explosion. I have a version with a die roll to determine chance of penetration too. It looks like 85% penetration is the minimum to cause spall damage that can disable a tank.

This is the info that I based the above chart on.