How does this work on multi-classed characters? The cleric spell is explicit in that it works by calculating your cleric level. But what if you're a fighter/thief? Or a mage/thief? Or f/m/t? Or any combo that doesn't include "cleric"? Which level is used for determining how powerful your DuHM is?

This is an innate spell, not a divine spell. So, it runs off your character level, not caster level.

but which character level? for instance, in a f/m/t, which is it? the fighter, the mage, or the thief?

All three added together.

I don't think that is accurate. I hope you're right, though!

I believe it takes whichever level is higher, not both (or all three) added together.

It's either the highest or lowest level. No way do you add all of your levels together.

7/7/8=22?

They <u>can't</u> be added together.

In this case, the level of your primary class. IIRC.

<font color=plum>But if you are multi-classed, then how does the game determine which class is your "primary" one?? Is it the class you choose first?

In PnP, the levels would be added together, then divided by the number of classes, so in the example given by <font color=gray>Iron Greasel</font> above, the PC's "level" for Draw Upon Holy Might would be 7 (22/3)</font>