Should I allow monster classes to crossclass?

[3Power]

In a campaign I'm running, one of the characters is interested in playing a succubus, which means she will be a glass cannon that absolutely murders every social encounter, but die actually pretty easy in combat By default, monster classes need to be progressed through the entire way.

So, I can either force the monster class progression first, allow free-cross-classing, or do some kind of *every X level must be a succubus level* thing.

What do people think would be best?

[Fax Celestis]

I don't see any real quandary with having it act like a regular class. She won't be a full succubus until she completes the racial class, but on the flip side, she won't have all the powers that a succubus can normally bring to bear.

[sonofzeal]

Yep. No problems allowing fluid multiclassing. You may want to mandate a certain minimum level depending on the monster class, or have her relative ineptitude at Succubus-ing be an RP/plot point, but there's no balance reason not to allow it.

[Vangor]

The only reason to limit monster class multiclassing before being finished is if the intent is to qualify for something clearly broken. For instance, though I do not believe such a monster class exists, taking a single level of beholder and then progressing beholder mage would deserve two DMGs hurled at you.

[Runestar]

The only reason to limit monster class multiclassing before being finished is if the intent is to qualify for something clearly broken. For instance, though I do not believe such a monster class exists, taking a single level of beholder and then progressing beholder mage would deserve two DMGs hurled at you.

There are some monster classes which are fairly front-loaded, like ghaele or trumpet archon. 5 lvs gives you full (or better than full) spellcasting with outsider HD and misc goodies.

It is the sort of thing which will need to be evaluated on a case-by-case basis, because not all progressions were created equal. In the case of the succubus, I don't see anything problematic about it, it really is a very weak class to begin with.

[Vangor]

There are some monster classes which are fairly front-loaded, like ghaele or trumpet archon. 5 lvs gives you full (or better than full) spellcasting with outsider HD and misc goodies.

Well this is not limited to monster classes. For instance, no taking a single level in spelldancer.

[The-Mage-King]

Why not try this (http://www.giantitp.com/forums/showpost.php?p=7951939&postcount=29) version of the aforementioned monster class? Less squishy, a bit more balanced, and probably more fun to play.