I realize that a mystic theurge is basically 2 casters 3lvls lower than my character in one body. a mix or arcane and divine, but I think the possibilities are still intruiging. I am currently wondering what role a mystic theurge would be best at filling. In each role the theurge would have weaker spells, but notably more spells. Which role can take the best advantage of this? A buffer, debuffer, blaster, or some other role I'm not thinking of. (I would really rather not be a heal bot)
Support spellcaster – buffs, debuffs, battlefield control. Which is mostly what a wizard already is.
The mystic theurge has poor BAB, as does wizard, and having arcane spellcasting makes the use of armor difficult despite your proficiency. As such, self-buffing and going into melee, as a cleric might, is pretty much out. That’s a shame, because most of the particularly-good spells that the cleric gets and the wizard doesn’t, fall into that category.
So that means you fall into a support role, which the cleric is of course perfectly good at, and the wizard is absolutely superb at. The cleric spellcasting adds a few buffs, but nothing amazing, and healing, which mostly sucks until you get heal itself, but that spell itself is quite good. But you get it much later than a cleric would, and of course your wizardly spellcasting is similarly behind.
You will have access to stuff like remove disease or restoration, which are definitely nice, but only if your party lacks other ways to access them. They aren’t every-day needs, so most of the time it’s safe to have relatively-inefficient access to them.
This is the real problem with mystic theurge: you lose a massive amount of power, because of the delayed spellcasting, but in theory that’s part of the deal of a prestige class, there’s a trade-off. Leaving aside the issue that three spellcasting levels is an absurd amount of power that is almost impossible to find an equitable trade for, the things that mystic theurge offers are just... more of the same, or more of the things you would be able to do if you’d been single-classed. You don’t really get much that a single-classed wizard wouldn’t (more-or-less) have anyway (aside from heal), while compared to a cleric, you give up any real opportunity to use your unique effects (aside from heal) and get a shoddy version of the wizard’s forté in return.
So it’s never a good trade, relatively speaking. The heal spell just isn’t worth it, and it really is just about the only thing that
- you wouldn’t have if you weren’t a mystic theurge,
- is actually really good, and
- you can still use while also being a wizard.
But with that said, a mystic theurge is still a phenomenally powerful character. Choosing to sacrifice power is, in this case, a quite-valid option: clerics and wizards have power to spare. I wouldn’t do it in a game with other high-power classes, but in a low-power game, especially one in which there are no other spellcasters, it could be quite safely powerful enough to have fun, and could even be convenient (get to play with wizard spells, but also have the party’s occasional restoration available). This convenience is not, optimally speaking, worth the cost, but if you enjoy the concept, the party could use it, and you are playing in a low-power game, it can probably work.
Combined Spells (Su): A mystic theurge can prepare and cast spells from one of his spellcasting classes using the available slots from any of his other spellcasting classes.
Example of Application: Lower Level debuffs from arcane spells can be meta-magicked using higher level divine spells slots. For example, Casting a Quickened Ray of Enfeeblement would count as a 6th level Cleric spell, and would allow you to use another debuff in the same round, such as Touch of Idiocy. Going up against another spellcaster could render his strength way below 10, and possibly encumbering him. While the penalty to his mental scores could seriously cause him to have a bad day.
Spell Synthesis (Su): At 10th level, a mystic theurge can cast two spells, one from each of his spellcasting classes, using one action.
Example of Application: If you chose Druid and Wizard, you could cast Sirocco twice in the same round, at the same time as one action, and could still utilize a swift action, and a move action. Doing this spell twice would make the opponents exhausted which is a tremendous advantage to your party, and deal a decent amount of damage, while possibly knocking them all prone.
Since you won't necessarily have 'show-stoppers' as far as spells, you could very well have many 'crowd-pleasers.'