🚀 go-pugleaf

Does anybody know how Walter Bright's PC Empire conducts combat?
I seem to run into a lot of very unlikely combat results, like an army
doing 2 points of damage against a destroyer.

The manual talks about how the two pieces 'trade hits' until one is dead.
Assume piece A attacks piece B.  I imagine what Empire does is roll to see
if A hits B.  Apply damage to B if A hit.  Roll to see if B hits A.  Apply
damage to A if B hit.  Continue.  My question is, how do you calculate
the probability of A hitting B given the attack factor of A and the defense
factor of B?

There is also another way combat could be conducted.  Assume A attacks B.
Based on attack and defense factors, there is a certain probability that
A will hit B and otherwise B hits A.  Damage is applied.  Repeat.
Does anyone know if this is how combat is conducted?

Chris Marshall