Phoenix Forums

Mandible

Bell curves are a mystery to me

From the rule book it says that targetting is :

"The bell curve for the hit determination gives a peak at 7.5 (= 2.5 + 2.5 + 2.5). This means that firing weaponry with a total accuracy of greater than this value will have more than a 50% chance of success. Beam weapons with an accuracy of +6 have a minimum bonus of +9 before any targeting bonus is applied. This means that they have very little chance of missing. The significance of a bell curve is more profound when the total accuracy is around 7.5. If the accuracy shifts even slightly in one direction or another, there is a dramatic change in the chance of hitting. This is because the curve represents the likelihood of a generated number falling at such a number. So total accuracies greater than 11 give a near perfect chance of success, while total accuracies less than 5 give very little chance of hitting."

Is there a formula I could use to work out the % chance to hit a given targetting bonus has? The only one I can work out is a to-hit of 7.5 has a 50% chance of hitting the target :-)

mark

Steve-Law

Not from that passage there isn't

ptb

although if you have a number of battle reports (which show how many of your weapons hit etc) then you could caluclated a pretty good approximation of hte bell curve they use.

David Bethel

CODE

Acc %
0 0
1 1
2 2
3 5
4 9
5 16
6 26
7 38
8 50
9 63
10 74
11 84
12 91
13 95
14 98
15 99
16 100

This is the table the program uses for acc - > %
However note that it rounds the accuracy (before using it) to the nearest integer. So 7.5 ->8 ->50% so taking the % can be a little misleading.

ptb

intressting, what prompted the decision to round it rather than have a gradual curve from some kind of formula?

hehe the manual is a little misleading when it says 7.5 is 50%, which although tecnically true, could have been 7.5 -> 8.49 is 50%

Dan Reed

Probably the fact that the list above is a table rather than a formula...

But while I agree it would be nice, even if approximated by staight lines between the integer points, it's not likely to make a significant difference overall, except that people will aim for accuracies that just creep above the .5 threshold to get to the next step, rather than being able to decide whether that extra 1% chance to hit is worthwhile....

Dan

ptb

don't forget it's modified by dodge extra so chances are if your just on the edge it won't help much

I was only wondering about the use a table from a programtic point of view.. techy things intresst me (in case that wasn't all too obvious by now)