How much does a stat change when it is "raised" or "lowered by one grade"?
In Steamworld Quest, many cards will raise or lower different stats in "grades". How much is the stat effected for each grade?
For example, the card Shout "Lowers all foes' Strength by one grade for three turns" and Shields Up "Raises an ally's Physical defense by two grades for three turns".
Solution 1:
For buffs, the boost is a straight percentage, subject to diminishing returns. You can check this using the menu in battle, and examining your characters. It works the same for both Strength and Magic, and any elements.
- +1 = 25%
- +2 = 40%
- +3 = 50%
- +4 = 57%
If you can combine both elemental boosts along with Strength or Magic, the increase is multiplied. +1 Fire and +3 Magic doesn't equal an extra 57% to damage; it equals 1.25 (for your +1 Fire), and then the result gets multiplied by 50%, which results in a 87.5% boost to magical fire attacks.
Will continue researching to discover how defenses work; I suspect it's something along the same lines, but that's harder to test, because defenses don't have a handy stat value to compare.