

If you look at the later sheet in the tool, there is a table of damage range verse ratios. My understanding is the tool was built by carefully recording this value for a very large number of battles where they knew the base attack and defense values, were able to adjust them for the stated terrain and unit to unit adjustment, and came up with a listing of each given ratios yielded a specific damage range.

The random factor is which of these number will occur, but there is NO random factor in determining the damage range. When you hover your mouse over an enemy unit (if you are on the Browser version), one bit of information you get it the damage range the attack will do, something like 4-6 or 5-7 pointe of damage.
