EDG said:Rikki Tikki Traveller said:Roll 3D, if ATM 4-9, drop the lowest, if ATM other than 4-9, drop the highest.

How do you figure out the probability spread for something like this? At least with straight DMs the probabilities are pretty straightforward and intuitive.

Here is a 2d keep lowest and 2d keep highest. Note: out of 216 chances

3d keep low 2d

2 = 16

3 = 27

4 = 34

5 = 36

6 = 34

7 = 27

8 = 19

9 = 12

10 = 7

11 = 3

12 = 1

3d Keep High 2d

2 = 1

3 = 3

4 = 7

5 = 12

6 = 19

7 = 27

8 = 34

9 = 36

10 = 34

11 = 27

12 = 16

gives a nice skewed bell curve with the same range

And here's the python program which crunched the numbers.

Code:

```
set = [1,2,3,4,5,6]
low = [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]
high = [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]
for a in set:
for b in set:
for c in set:
x = []
x.append(a)
x.append(b)
x.append(c)
x.sort()
y = x[0]+x[1]
z = x[1]+ x[2]
low[y] = low[y]+1
high[z] = high[z]+1
print x,y,z
print low
print high
for x in [2,3,4,5,6,7,8,9,10,11,12]:
print x, "=", low[x],",",high[x]
```