I reviewed the code and yes it's % based as Keeper mentioned.
And @Nolio is also correct, a percentage based buff actually gives an advantage to units that start out stronger than it does to weaker units because they're getting a % increase based on a higher starting number.
On the flipside, a flat point increase would perform the reverse of that and give units that have smaller starting stats a bigger buff than units that already had a high starting point (human infantry going from 5 to 6 would be +20%, elf swordman going 3 to 4 is +33%, gnome infantry going 2 to 3 would be +50%).
Which is “fairer”?
-% approach keeps the relative strength ordering intact: the best-armored units get the biggest raw gains, reinforcing their design niche.
-Flat-point approach gives a bigger relative growth to the underpowered units, helping weaker races catch up, but risks overshooting balance.
It may seem at first glance that % based is the fairest way to go so everyone gets a simple little boost, without hugely unbalancing things, but there's another thing to consider in this which is easy to overlook...
Armored units per race
Human 6/6 (2 heavy)
Dwarf 5/6 (3 heavy)
Orc 4/6 (1 heavy)
Elf 3/6 (1 heavy)
Gnome 2/6 (1 heavy)
Having more units armored also gives a much bigger difference in raw defensive points to races that have more armored units versus races with fewer armored units. In fact, according to my calcs humans gain roughly 6X more defense points from techs than gnomes do, based on a percentage gain. If we switched to a flat points system, the disparity in defense points gained would reduce roughly by half, improving the disparity to Humans only gaining a 3X advantage over Gnomes.
If we changed to flat point system, I think it would actually be fairer across the races. It would help Orcs and Elves more than anyone else. Gnomes would still suck because Infantry train so slowly (same slowness as Orc Rusher, or Elf Swordman, or Human Infantry).
Would a Gnome Infantry unit be getting a decent boost compared to other races equivalent units? Well sure, it would go from 2 to 6 defense (+200%), while a comparative unit like Human Infantry goes from 5 to 9 (+80%), but we shouldn't conflate those differences to meaning the Gnome gets a bigger benefit when the Gnome is only getting 1 single unit buffed, while the human is getting 4 units buffed from the same tech. In the same time a Gnome can make 1 Infantry, a Human can make 1 Infantry and 1 Archer.
For all those reason, I think we should switch to a point system.
