IcyCool said:
You are 3 spell levels behind in both casting classes, you still suffer arcane spell failure so you'll probably have to give up your heavy armor (loss from the cleric), you give up the good fort saves of the cleric, you get d4 hit dice (as opposed to the d8 hit die for cleric),
See below
and you can't get 9th level spells in both classes by level 20. (Wiz 5/Cleric 5/Mystic Theurge 10 = 15th level Wizard Caster and 15th level Cleric caster, which means 8th level spells in both.).
I'd figured that the most effective spend would be a 3/7/10, honestly, with the 7 being in whatever class he wanted 9th level spells in. But being able to cast 8th level divine and arcane spells is nothing to sneeze at either.
And the lack of 3rd level spells provides a sufficient barrier to entry, as it will be difficult for the character to survive long enough to get into the Prestige Class.
I'm not worried about this IMC.
Also, unless you invest two feats into Practiced Spellcaster (arcane) and Practicec Spellcaster (divine), you can pretty much forget about penetrating spell resistance.
I'm suspicious that a difference of three makes that much difference on the roll of the d20; especially since the character has the Luck domain for the occasions where that 15% causes a failure.
This looks to me like the opportunity for the player to create flavor. Flavor shouldn't have game mechanics IMO.
When a class is taken for its game mechanic advantages, I expect it to provide some of the flavor for me, YMMV. This is not a situation of "I have this neat idea for an order of wizard priests and would like to take a prestige class of dubious benefit in order to roleplay becoming a member," but a case of "I would like to take this prestige class that provides game advantages but no story." I could do the work to make it into an interesting class, but I think it would only be attractive because of its game benefits and the flavor I added would be lost. Again, YMMV.
So if the situations the party has been in throughout the last three levels were instead combat encounters with the enemies grouped nicely together and the wizard killed them all with nicely placed fireballs, would that make the wizard overpowered? Your line of reasoning seems to indicate yes.
Indeed. If I had envisioned a campaign where most combat encouters involved mooks that traveled in 20 foot diameter packs, I would have noted that I was adjusting the core rules to remove fireball before anyone committed to playing a wizard. Since I'm running a campaign where a cheap column of buffs and utility spells that don't detract much from the ability to contribute in a primary role, I'm noting that I think the Mystic Theurge is too powerful before allowing anyone to commit to playing one (by multiclassing into Wizard).
Ah, so the problem isn't that Mystic Theurge is overpowered, it's that your house rules and gming style make it seem that way.
I don't think I've ever opined otherwise. IMC, I forsee the class causing problems, and I don't think it's cool enough to be worth overcoming them.
Honestly, even with the increased buff durations Mystic Theurge isn't as nice as a single classed caster.
I believe otherwise. I see the potential for a wizard's worth of spell slots that can be used entirely for buffs and utility, while a normal wizard would balance buffs and utility spells with options to contribute directly to combat. IMC, I believe enough this would cause a problem that I don't want to playtest it for another year and then force the player to respend his character if I determine that, indeed, I was right.
You mention that armor won't be prohibitive for buffs (and if you are using the longer durations, I agree), but what, exactly, is your Mystic Theurge doing during combat? Beating the enemy mightily with his Wizardly base attack bonus? Soaking up the hits with his mighty d4 hit dice? Dropping his foes with divine magic (provided said foes don't have magic resistance)?
So far? Standing in the back, dropping AoE divine debuffs, healing the party, sometimes getting a hit off, and wearing too much armor to be the prime target of the NPCs that are actually trying to even the odds. Nothing that has happened so far would lead me to believe that being somewhat closer to a Wizard would hinder his normal method of operation. And I forsee being able to round himself out with an array of buffs to be likely to mitigate a lot of the difference between wizard and cleric.
I know it seems I'm picking on you, and rest assured that I'm not, but if your only real complaint is that he can cast a bunch of buffs to make the party more effective in combat, do you also outlaw the Bard?
No, that's just the only complaint that you seem to think is real

. I have several complaints, none of which add up to a damnation of the class but which make me unhappy enough with the idea of allowing an optional class that I don't intend to do so. The bard has fewer available buffs and utility spells than a Cleric/Wizard, and can only know a limited number of them. A properly prepared MT could conceivably cast any spell in the game with only a day's warning.