"Have I got this math right?" Topic

Okay so using a D10 you must roll your fire value or less to hit. So Fire value 1 = 10% chance to hit.

If the target is in soft cover you must roll 2D10 and hit on both. So fire value 1 = 1% (0.10 * 0.10) chance to hit, fire value 5 = 25% (0.5 * 0.5) chance to hit.

If in hard cover you roll 3d10 and must hit an all 3. So fire value 5 = 12.5% chance to hit (0.5 * 0.5 * 0.5) and fire value 9 = 72.9% chance to hit (0.9 * 0.9 * 0.9).

Sounds right to me as far as the maths goes.

According to my arcane Excel wizardry, yes, you've got them right.

Arabic

Klingon

Holy you know what.
I come to play my nerd games to have fun not to do nerd math.
You sir made my head hurt. :-(

Grimm

Figure out the chance of missing. Each time you add a die, you deflate the hit chance by the chance of missing with the prior set of dice. The hit chance is always the miss chance subtracted from 100%.

For FV5,
1 die: Miss(1) = 50% ;
so Hit(1) = 100% – Miss(1) = 50%.

2 dice: Miss(2) = Miss(1)
+ Hit(1)xMiss(1)
-----------------
= 50% + (50%x50%) = 50% + 25% = 75%
so Hit(2) = 25%

3 dice: Miss(3) = Miss(1)
+ Hit(1)xMiss(2)
----------------------
= 50% + (50%x75%) = 50% + 37.5% = 87.5%
so Hit(3) = 12.5%.

Nerd games are more fun if you know the chance of your actions succeeding and failing. That way you can make intelligent risk assessments. Like real commanders are supposed to.

The maths is correct, but odd at the extremes. Firepower 9 is 81 times better shooting at soft cover than Firepower 1. Much more extreme for hard cover. You might consider using a single 'cover' dice needing (say) 6 or less to hit soft cover, 3 or less if in hard cover. Then the firepower ratios stay the same when firing in the open or at cover.

Yes, correct.

BTW, I am running a series of articles (well, 2 so far), dealing with dice mathematics on my new blog:
wargaming-mechanics.blogspot.be

I am writing one about this specific topic: probabilities for scoring at least 1 hit, since that is an issue confounding to many people.

Yep.

1d10 (<=): FV1 = 10%, 5 = 50%, 9 = 90%

2d10 (both <=): FV1 = 1%, 5 = 25%, 9 = 81%

3d10 (both <=): FV1 = 0.1%, 5 = 12.5%, 9 = 72.9%

Here's a link to a great dice probability tool, that has taken the headache out of my number crunching:

link

Cheers,

Christopher

What advocate said.

+1 Grimmnar

Nerds…. I was already sweating after "…using a D10" ,-)

Correct maths but I agree it looks a bit strange. Firepower 1 shooting sat a target in soft cover is reduced to 10% of its normal effectiveness, whereas firepower 5 shooting at soft cover is only reduced to 50%.

"but odd at the extremes" agreed.

Instead of repeatedly using the attacker skill add a defense die that is rolling against separate variable. Say soft cover has 50% blocks. Hard cover has 80% blocks. Attacker has to roll his number and NOT a block.

Then it's easy to see the advantage of the different types of cover.

Not my game I was just wondering if my maths were up to snuff…