ElliotM wrote:Does Denk's modification have this center bias?

Yes, it has center bias when rolling two or more dice.

As an example, lets take 2D4.

In my file, the result is simply found as:

2D4 result = rand(1,4)+rand(1,4)

Each rand(1,4) represents the roll of one die.

There is only one way to achieve the result 8. That is if both dice gives a four (4,4)

The same goes for the result 2 (1,1).

But the center value 5 can be achieved in 4 different ways: (2,3) (3,2) (1,4) (4,1)

Thus it is 4 times more likely to give the result 5 than e.g. 8.