I've done more testing. The technology advantage in combat is reversed from what seems to be intended.
All other factors being equal, the player always suffers more losses against Primitive targets and less losses against Superior targets. That is, Superior planets are easy to conquer and Primitive planets are really hard to conquer.
I'm looking at the code, but I haven't pinned down where exactly the reversal occurs. I'll comment again if I ever find it.
I found where the reversal happens.
GameRules.ms, Lines 17, 18, 26, and 27 read:
winner = (rnd < p)
spaceForces[1 - winner] -= 1
...
winner = (rnd < p)
landForces[1 - winner] -= 1
...The way "winner" is treated in Lines 18 and 27, "winner" is SUPPOSED to represent "which side (0 or 1) won a specific round of combat". (dialogs.ms always treats the Empire as side 0 and the Independent planet as side 1.) HOWEVER, "p" is SUPPOSED to be the probability that side 0 wins a round of combat.
If side 0 has a large tech advantage over side 1, then "p" is large, "rnd" is more likely to return a number less than "p", "rnd < p" is more likely to return 1, which makes "winner" equal to 1, then spaceForces[1-1] (in other words, spaceForces[0]) is decremented, and the victorious Empire loses a ship. :P
...
This is an easy fix. Lines 17 and 26 must both be changed to
winner = (rnd > p)
to fix this problem. This should work properly even if this code is later used for fights not involving the Empire.
