Combat Odds is insanely skewed by the amount of damage you do each round. For example, if you do 19 damage you need 6 successful hit to kill your target instead of 5, a MASSIVE increase in %. If you lower the damage range to 2 instead of 20 you would increase this skewyness by a ALOT. Someone doing 1 damage would need 50 more rounds than someone doing 2 damage, 66 more rounds than someone doing 3 damage.
There is a reason why HP can currently change the odds alot.
Currently, if the ratio between two units is 1.01 vs 0.99 in strengths and they are somehow of full HP, the 0.99 unit has 38% to win, cause he does 19 damage per round and the 1.01 unit does 21.
I'm trying to emulate the effect of changing to 1000 HP via combat damage. As far as I can tell, multiplying all HP numbers by 10 is nearly the same as dividing all damage/hit numbers by 10; it's the HP/damage ratio that gives you the number of rounds of combat (both minimum, and average). The nice thing is that the engine seems to handle changing the combat damage better than the HP. The number of First Strikes (and Stoneskin) would still need to be changed to get roughly the same effect - note that if this was done with a C++ change, it could be limited to a tiny number of functions. However, Healing would not need to be touched.
Basically, the peak of the curve increases as the number of rounds go up (sacrificing probability from the extremes). That means that someone with a marginal advantage at a ratio of 5:1 (HP:damage) has a larger advantage as the ratio increases, and a smaller advantage as it decreases.
Personally, I think that if people really like this approach, we should see if Snarko would be willing to put it into his options mod- something like:
Combat Randomness:
High (50 damage/hit)
Vanilla (20 damage/hit)
Low (10 damage/hit)
Very Low (5 damage/hit)
Extremely Low (1 damage/hit)
The damage each round isn't always 20, its a variation from 6-60, and replacing 20 with 2 would make that range from 1-6, now that is a bit extreme don't you think?
Combat Explained
I'm not familiar with the text you cite; I'm basing my investigation on CvUnit::updateCombat.
There is no randomness to the damage calculation; merely to the number of rounds.
Damage Calculation 1 (Defender does damage):
Damage Calculation 2 (Attacker does damage):
When you look at the basis of these numbers,
Firepower is the (Max strength + the current strength + 1) /2
and
iStrengthFactor is the (Attacker's firepower + the Defender's firepower + 1) / 2.
So, for an extreme example, a strength 80 vs strength 1 unit (both at max HP, no terrain mods) would do:
Firepower of Str 80 = 80
Firepower of Str 1 = 1
iStrengthFactor = 41
So if the strength 80 unit hits using the vanilla combat damage:
max(1,(20 * (80 + 41))/(1 + 41)) = max (1,(20*121)/42) = max (1,(2420/41)) = max(1,59) = 59 points of damage
If the Str 1 unit hits:
max(1,(20 * (1 + 41))/(80 + 41)) = max (1,(20*42)/121) = max (1,(840/121)) = max(1,6) = 6 points of damage
Conversely, using 2 for the combat damage:
max(1,(2 * (80 + 41))/(1 + 41)) = max (1,(2*121)/42) = max (1,(242/41)) = max(1,5) = 5 points of damage
If the Str 1 unit hits:
max(1,(2 * (1 + 41))/(80 + 41)) = max (1,(2*42)/121) = max (1,(84/121)) = max(1,0) = 1 points of damage
This means that the weak unit is relatively a bit stronger, on a per round basis, using 2 as combat damage than the strong unit because it does more relative damage/hit (20% of the damage of the strong unit, instead of roughly 9%). however, the 10-fold increase in average combat rounds more than offsets this; in the first case, the weak unit would need to hit 17 times before being hit twice; in the second case, the weak unit would need to hit 100 times before being hit 20 times.
So, no, I don't think that lowering the range of combat damage is a bad thing; it's merely different. Unless it's a death, it's not like you notice the difference between 4 points of damage and 5 points of damage much, anyway. The combat odds/round are still the same (and essentially calculated in the same way as Civ I)
So I guess the end result of this discussion is that I'd suggest you try changing the COMBAT_DAMAGE, try a few combats via a world-builder setup, and see if you like the results (note that just changing COMBAT_DAMAGE means that First Strikes and Stoneskin are far weaker- unless they're also changed). It seems to me that what will happen (if you adjust it downward) is that the stronger unit will win far more frequently than the weaker unit, but the weaker unit is much more likely to damage the stronger unit.
