It's not broken, however it doesn't make you incredibly overpowered as one might think. I'll give you an example of how the gun upgrades with some numbers: The base rifle deals 100 damage. Through each upgrade, it adds 50 more damage, so the max level rifle upgrade is 300 damage. To compare this with an enemy, Skeletons have 300 health. So at a max gun upgrade, you will be one shotting them. Head to the Bestiary from the menu to see more enemy information.
You should explain promotion sooner. I ended up using some of my doubles to upgrade characters only to find out that I needed them to promote my characters.
It is interesting that even though the stats on a character with a lower level may be higher than those of one with a higher level, they still perform worse simply because their level is lower. I feel like this needs to be looked at.
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 "Battle for Blood"){kind=icon}
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It's not broken, however it doesn't make you incredibly overpowered as one might think. I'll give you an example of how the gun upgrades with some numbers: The base rifle deals 100 damage. Through each upgrade, it adds 50 more damage, so the max level rifle upgrade is 300 damage. To compare this with an enemy, Skeletons have 300 health. So at a max gun upgrade, you will be one shotting them. Head to the Bestiary from the menu to see more enemy information.