[2023] Explain gear vs character stats

The stats on your gear are likely increased mana regen. This is a relative value to your base mana regen, not a percentage of your overall mana returned to you per second.

You have (base + added1 + added2) * (1+increasedValue1 + increasedValue2) * (1+moreValue1) * (1+moreValue2)

So for your mana regen, you had 37% increased mana regen that totaled to 12.