What does Arcane Might actually do?

[Coldbringer]

"Add 50% magic modifier to all weapons. "

I don't understand what that description means. Magic modifier? 50% of what?

A better question is, would this help my Reaver much, or would I be better off taking Flexible Combat or I Can Carry The World?

[Effigy]

It's an additional damage scaling mod based on your Magic stat. A one-handed sword have 100% Strength damage mod; with Arcane Might, you would do 50% more damage assuming your Strength and Magic are equal.

[stinkstink]

This page has an in-depth breakdown of the melee damage formula, but putting it simply: the prodigy adds 50% of your Magic as a modifier stat to your melee attacks in addition to the usual stat modifiers (100% STR on most one-handed weapons, 45% STR/DEX on daggers, etc.) If you're using weapons with 100% STR modifier, Arcane Combat is better than I Can Carry the World if you have more than 80 Magic.

[Coldbringer]

oh now I get it. the weapon(s) get bonus damage equal to 50% of my magic stat.

Maybe I should have gotten that instead of Flexible Combat for my reaver. Hm. Not sure it's paying off yet.

I know the next one is going to be the wind AOE that does like 300% weapon damage. Just have to get dex to 50 first