Today I'm going to explain to you a super simple method I've developed for quickly calculating how many of something you can expect to kill by shooting or close combat. I've named it 'Method 216' for reasons that will become very obvious to you when I'm done explaining how it works. Before we get into 'Method 216', let's go over some very basic things about probability. Very often we are going to need to know how many sides of a D6 will give us a successful roll of the dice. This is quite easy to figure out. Let's say a Space Marine is shooting his bolter at a Necron warrior 18" away. The Space Marine needs a 3+ on a D6 in order to score a hit, so there are 4 sides of the D6 that will result in a successful roll, because a 3, 4, 5, or 6 will result in a hit. So if I were to ask you how many sides of a D6 will result in a successful roll in the previous example, you would say 4. The same would be true for rolling to wound, if a bolter with a S4 will wound a Necron warrior with a T4 on a 4+ then you would say 3 sides of a D6 will result in a successful roll.
Take note that in the case of your opponent making an armor / cover save it's a little different because a successful roll for your opponent is a failure for you. So because the Necron warrior needs a 3+ to make his armor save, then a 1 or a 2 will result in a successful dice roll for you. So if asked how many sides of a D6 will result in a successful dice roll for you when the Necron warrior rolls for his save, you would say 2.
Now then here is how the 'Method 216' works...
(H * W * S) / 216 = average number of kills
H = # of sides on a D6 that will result in a hit
W = # of sides on a D6 that will result in a wound
S = # of sides on a D6 that will result in your opponent failing his armor / cover save
Let's go over a few examples...
1) Space marine firing at a Necron warrior 18" away.
SM needs a 3+ to hit, a 4+ to wound, and Necron warrior needs a 3+ to save.
3+ to hit = 4 sides of a D6 to hit
4+ to wound = 3 sides of a D6 to wound
3+ armor save = 2 sides of a D6 to kill
Plug in the numbers and you get (4 * 3 * 2) / 216 = 0.111111
So the SM on average should kill a Necron warrior about 11% of the time, if you have a unit of 5 marines firing, then just multiply the .111111 by 5 to get .555555. Or in other words the 5 marines can expect to kill .555 Necrons per round of shooting.
2) 3 Necron Heavy Destroyers firing at a squad of Space Marines.
Necrons need a 3+ to hit, a 2+ to wound, and Space Marine does not get a save (S9 weapon vs T4).
3+ to hit = 4 sides of a D6 to hit
2+ to wound = 5 sides of a D6 to wound
no save = 6 sides of a D6 to kill
Plug in the numbers and you get (4 * 5 * 6) / 216 = .556
So each Heavy Destroyer should kill a SM 55.6% of the time, or as a squadron of 3, they should kill .556 * 3 = 1.667 Space Marines per round of shooting.
3) 12 Necron warriors shooting at a unit of Terminators less than 12" away.
Necrons need 3+ to hit, 4+ to wound, and Terminators need a 2+ to save. Necrons get double number of shots since they are within rapid fire range.
3+ to hit = 4 sides of a D6 to hit
4+ to wound = 3 sides of a D6 to wound
2+ armor save = 1 side of a D6 to kill
Plug in the numbers and you get (4 * 3 * 1) / 216 = .0555
24 shots * .0555 = 1.33 Terminators per round of shooting
Once you have done this a dozen or so times it should become very easy, and you should be able to figure it out during a game quickly using the calculator that comes with your cell phone.
That's it for today, hope this helps you crush your foes in battle, let me know if you have any questions. In the future I'll post some more advanced Mathhammer concepts.
- By the way, the number 216 that you divide by comes from the fact that to kill someone three dice rolls have to take place, hit, wound, and save. So 6*6*6 = 216. Chaos players might prefer to call this 'Method 666'.
