Need help with a Mystic Theurge

[Trickster]

I'm creating a Mystic Theurge and so far I've decided I'll take Wizard/Cleric levels. My first question is: Should I take Wiz3/Cle2 or Wiz2/Cle3?

My second is what should I do with the last five levels? Should I take Wizard and Cleric to 5 each? Or should I take another PrC?

Lastly, what race should I pick? I originally thought about some sort of Elf, then I looked at Dweomerkeep and saw the human restriction. Is there a better race to fit this build?

[Anthrowhale]

I'm creating a Mystic Theurge and so far I've decided I'll take Wizard/Cleric levels along with 10 Mystic Theurge levels. My first question is: Should I take Wiz3/Cle2 or Wiz2/Cle3?

My second is what should I do with the last five levels? Should I take Wizard and Cleric to 5 each? Or should I take another PrC?

Lastly, what race should I pick? I originally thought about some sort of Elf, then I looked at Dweomerkeep and saw the human restriction. Is there a better race to fit this build?

For a mystic theurge build, I'd recommend Illumian Archivist 1/Wizard 2/Mystic Theurge <n> or Archivist 2/Wizard 1/Mystic Theurge <n> with the Improved Sigil[Krau] feat. That minimizes the degree to which your spell access is slowed and since Archivist and Wizard are both Int-centric you'll be able to be effective with both classes. Archivist is a reasonable alternative to cleric since it uses the cleric list via a wizard-style access.

[Eldonauran]

If you aren't opposed to undead stuff, the True Necromancer from Libris Mortis progresses both arcane and divine casting. Its a 14 level long prestige class that loses 2 casting levels from each side over the course of its progression.

Otherwise, I'd suggest simply making your wizard levels your highest (assuming you don't have to deal with any multi class experience penalties). It has the superior spell list.

[YellowJohn]

Mystic Theurge requires 2nd level spells as Arcane AND Divine so if you're not using cheese you'll need at least three levels in each class.
If you *are* using cheese, you can meet the skill requirements with your third character level so you only need Cleric 1/Wiz 3 or Wiz 1/Cleric 3. Which you pick is at least partly dependent on your choice of cheese; I would go
Cloistered Cleric (https://www.d20srd.org/srd/variant/classes/variantCharacterClasses.htm#:~:text=The%20cloister ed%20cleric%20spends%20more,and%20the%20protection %20of%20knowledge).) 3/Wizard 1 because Cloistered Cleric has the better chassis and allows the powerful Initiate of Mystra feat, but as Eldonauran rightly points out Wizard has the more powerful spell list.

Human is always a good choice for race - you will always be able to find a use for that bonus feat. (Lesser) Aasimar and Grey Elf are also viable options for the bonus Wisdom/Intelligence (and Wizard Substitution Level from Races of the Wild) respectively.
Bamboo Spiritfolk (OA p.14) have the 'Trackless Step' racial ability, which works the same as the Druid class feature. You can potentially talk your DM into allowing this to fulfill the 'Trackless Step Class Feature' requirement of the Arcane Hierophant prestige class (RotW p.108) which is Mystic Theurge with a druidic flavour. It's slightly better than Mystic Theurge on a Cleric base, and at the very least would round out Mystic Theurge nicely.
Don't let your desire to go Dweomerkeeper force you to be a human. The version in Faiths and Pantheons was updated in the Complete Divine Web Enhancement (https://www.tsrarchive.com/3e/More_Divinity.pdf), where a lot of the requirements were dropped including the race and exotic weapon proficiency. Incantatrix (PGF p.61) is another class whose requirements you are likely to meet almost by accident.
I was about to write off True Necromancer (LM p.51) as being a terrible class. And on its own merits it is. But after checking the lost caster levels aren't as front loaded as I thought so if you're only taking four to six levels to round out Mystic Theurge you could do worse.

[MaxiDuRaritry]

If you wanted to do psionics and arcane and divine, you could always do a convert-spell-to-power erudite (or even better, a psion with such an erudite as a minion) and gain psionic powers, along with arcane spells converted to psionic powers. And since there are quite a few ways to convert divine spells to arcane (such as through the bard spell list, Southern Magician, the Child of Eberron draconic archetype, and several others), that nets you all three, and without any need for multiclassing or prestige classes, allowing you to do anything else you want.

Regular psion is only really doable with this later on. Leadership, Undead Leadership, some other feat for a spellcasting minion, thrallherd, or just paying for access to spells from spellcasting services via a CStP erudite with the psychic chirurgery (https://www.d20srd.org/srd/psionic/powers/psychicChirurgery.htm) power to transplant spells-as-powers into your head. You could also get access to the mindrape spell, which should do the same, without any XP costs. And despite being marked as [Evil], there's absolutely nothing evil about it, or even particularly questionable, so long as it's used even vaguely responsibly.

[rel]

Even with early entry, a cleric / wizard MT is weaker than a straight cleric or wizard build.

Talk to your GM about letting you progress MT above level 10 and reduce the entry requirements to arcane spells 1 / divine spells 1.

Failing that you can go into Arcane Hierophant after you get MT to 10. You need trackless step so either make your race Bambo Spirit Folk or go with some flavor of elf and dip the Wildrunner PRC.

You can also use Uncanny Trickster, Human Paragon or Legacy Champion to progress Mystic Theurge above 10, but they will lose you more spellcasting than MT + AH.

[eBarbarossa]

Since you have a lot of lower level spells to play around with, War Weaver might be up your alley. It lets you spam all those buffs on your whole group instead of casting them on single PCs.

[holbita]

You can also use Uncanny Trickster, Human Paragon or Legacy Champion to progress Mystic Theurge above 10, but they will lose you more spellcasting than MT + AH.

Human Paragon? Are you perhaps using some homebrew there? Or am I missing something?

[Remuko]

Human Paragon? Are you perhaps using some homebrew there? Or am I missing something?

Racial Paragon classes are from Unearthed Arcana theyre only 3 levels long and you have to be a member of the race to take levels in it. 2 of the 3 levels in human paragon advance spellcasting.

[Trickster]

Ok, say my end goal here is to have a Library-of-Congress amount of spells, like the PHB x3, from what I see Wizard/Cleric isn't the best idea, so like Wizard/Cloisted Cleric/MT/AH? + Human for the Paragon and take Dweomerkeep?

[Anthrowhale]

Ok, say my end goal here is to have a Library-of-Congress amount of spells, like the PHB x3, from what I see Wizard/Cleric isn't the best idea, so like Wizard/Cloisted Cleric/MT/AH? + Human for the Paragon and take Dweomerkeep?

AH isn't naturally qualifiable here.

For access to virtually all spells without special allowances from the DM, I'd suggest you worship Mystra and then take Wizard 1/Archivist 3/Church Inquisitor 1/Divine Oracle 2/Hathran 5/Dweomerkeeper 8 .

With feats:
Human: ??
Wizard: Scribe Scroll
1. Ethran // prereq for Hathran
3. Extend Spell
Frog God's Fane: Skill Focus[Knowledge[Religion]]
6. Leadership // prereq for Hathran
9.

You'll have a prayerbook in which you can scribe every divine spell and a spellbook in which you can scribe ever wizard spell.

Church Inquisitor 1 provides a domain you can use the Substitute Domain spell on to get access to the Magic Domain to finish requirements for DK.

Divine Oracle 1 provides you can extra domain so you can again use Substitute Domain spell to get access to the Spell domain. This grants access to (Greater) Anyspell allowing you to cast any L5- arcane spell.

Divine Oracle 2 provides the ability to evade even in armor. It's skippable, but a nice filler.

Hathran 3 allows you to cast any known spell (=in a spell book or praryer book) with an explicit allowance for using a different classes slots (which is normally not allowed). This will eventually allow you to cast L9 wizard spells and L9 Archivist spells.

Hathran 5 gives you access to circle magic which is a nice power bonus although skippable.

And then Dweomerkeeper allows you to cast supernatural spells.

Altogether, you can cast an L9- Divine Spell, any L9- Wizard spell, and any L5- arcane spell.

Keep in mind that the cost of buying all those scrolls does add up.

[holbita]

Racial Paragon classes are from Unearthed Arcana theyre only 3 levels long and you have to be a member of the race to take levels in it. 2 of the 3 levels in human paragon advance spellcasting.

No, no... I know human paragon, my point is that it doesn't work the same way that uncanny trickster or legacy champion work. So it wouldn't advance mystic theurge like the other two.

[MaxiDuRaritry]

You could always take levels in illithid savant and eat a mystic theurge...

Just to round out the roster, don'chaknow.

[Gusmo]

Have you considered arcane hierophant? It'll only get you dual 9s, but you also turn your familiar into a great beatstick. Companion spellbond is a PHB2 feat that extends share spells to a range of 30 feet. druid3/wiz1/theurge6/arcane hierophant10 (or something like that) comes out with dual 9s and a burly animal companion with all the abilities of a familiar.

[rel]

No, no... I know human paragon, my point is that it doesn't work the same way that uncanny trickster or legacy champion work. So it wouldn't advance mystic theurge like the other two.

I may well be misremembering. As I recall there was some irregularity with the rules text of human paragon that lead to it being suggested for this sort of thing in the past.

I'm sure there are extensive arguments somewhere on the internet about what the exact issue is, whether or not it counts, the applicability of errata and so forth.

As I said earlier, I recommend ignoring the whole mess and house ruling MT directly.

[bekeleven]

OP: "How should I best build a cleric/wizard mystic theurge?"

Everybody in this thread: "Build a lawful good kobold spell-to-power psion // cloistered archivist with leadership into arcane heirophant gestalted with unarmed arcane swordsage using Illithid Savant"

Keep it together, playground.Or if you're really going for it, find a way to fit fochlucan lyrist in there.