Wow I hadn't heard of that. Can't say that I like it, but I doubt it's something a user could easily revert...
Japan had two big nerfs when BWN hit: the damage penalty from being wounded reduced to "up to -33%", and an adjustment that made the musketman +3
stronger than the Longswordman/Samurai (these three units used to have the same combat strength, so it didn't matter that they were close in the tech tree). Both nerfs had no meaningful compensation in the official patches, so Japan dropped considerably in most tier lists.
The CBP fixed the latter by making the Samurai slightly stronger than the Musketman (as well as coming earlier). The adjustment to the UA partially reverts the former. The "up to +10%
" means a favorable damage gap of 0-2 damage between your unit and an enemy unit of similar strength. I expect a "up to +30%
" to come very close of fully reverting it in practice.
For a detailed analysis of the UA, the game uses the following formula:
- Damage = 30 * ((((x+3)/4)^4)+1)/2
where x is the combat ratio between the combatants (stronger/weaker). For the weaker unit's damage, you invert after dividing by 2. So, in a 25
Samurai vs 21
Longswordman scenario, the damage of both is calculated as follows:
Code:
Samurai damage = 30 * (((((25/21)+3)/4)^4)+1)/2 = 33.067
Longswordman damage = 30 * ((((((25/21)+3)/4)^4)+1)/2)^-1 = 27.217
, assuming no other combat modifiers or penalty from being wounded.
If a non-Japanese/city combatant is wounded, it falls linearly from 30 to 20 (would be 15 before BNW). So, if you put two equivalent and fully wounded units to fight each other, the japanese one would deal +100% more damage in vanilla and +50% more damage in BNW. In CBP, we have (assuming no other combat bonuses):
Code:
Japanese damage = 30 * ((((1.1+3)/4)^4)+1)/2 = 31.557
Other civ damage = 20 * (((((1.1+3)/4)^4)+1)/2)^-1 = 19.013
, or a +65% more damage, up from +50%. If the Bushido bonus was a "up to +30%
", we'd have:
Code:
Japanese damage = 30 * ((((1.3+3)/4)^4)+1)/2 = 35.032
Other civ damage = 20 * (((((1.3+3)/4)^4)+1)/2)^-1 = 17.127
, or a +105% more damage (+8 damage gap), closer to what you'd have in vanilla. This also gives an idea of how big the BNW nerf was for Japan.
Remember, though, that combat bonuses stack additively, and aren't to be confused as combat ratio (x). A +30%
and a +10%
result in a +40%
together, not a +43%
. That means that, as both combatants accumulate sources of combat bonuses (promotions, general/admiral, terrain, flanking, fortification, wonders, policies/ideologies, beliefs, monopolies, UA), any additional bonus offers less impact in terms of combat ratio (x). In other words, combat bonuses have a diminishing return.
So, if both fully wounded combatants of same base strength have a +45%
(say, Shock III and Great General), a +10%
Bushido means:
Code:
Japanese damage = 30 * (((((1.55/1.45)+3)/4)^4)+1)/2 = 31.061
Other civ damage = 20 * ((((((1.55/1.45)+3)/4)^4)+1)/2)^-1 = 19.316
, or a +61% damage difference, while a +30%
Bushido would have:
Code:
Japanese damage = 30 * (((((1.75/1.45)+3)/4)^4)+1)/2 = 33.353
Other civ damage = 20 * ((((((1.75/1.45)+3)/4)^4)+1)/2)^-1 = 17.990
, or a +85% damage difference (+6 damage gap), instead of +105%.
Since Bushido is based on how wounded your unit is, such examples are extreme cases, and you can expect a 0-1 favorable damage gap from the "up to +10%
" Bushido in most engagements. I don't expect the "up to +30%
" to surpass a favorable 1-4 gap in most engagements due to how wounded your unit would have to be, and how many combat bonuses would have to be omitted.