So, I'm joining what seems to be a relatively high-powered D&D game soon, and I'm looking at running an Archivist - actually, my heart/mind is pretty much made up on that part.
Where I'm gravitating is versus just going Archivist20 (well, honestly, probabaly Archivist/FullProgressionCasterPrestigeClass) or trying to do the backflips necessary to make Archivist/Wizard/Mystic Theurge a viable build. I know in general MT is anti-optimization, but this is a different circumstance than usual. I'm the only caster in the group.
We have a Barbarian (hopefully filling the role of BSF and not Glass Cannon) and a halfling rogue(skillmonkey, might do damage but it's still a rogue.) So I'm going to have to pretty much handle all the arcane and divine needs of our little pack, and part of me is thinking that this in general is what MT should be made for.
We're running Pathfinder, which for the uninitiated you can consider to be 3.5e on crack- MTs don't really get anything with it though, beyond the standard d6 caster hitdice. It's not really relevant as much as normal here since most of our sourcebooks are still 3.5e - and I've been given pretty wide stepping room in regards to where I can dig up spells to take for the Archivist. Main thing to remember is that Polymorph, as a group, has been nerfed to slightly more sane levels.
I think what I'm curious/concerned about is, will a raw Archivist have the spells per day/spell selection to cover the roles the not-mages can't? Should I try to get the Precocious Apprentice Wizard->Archivist->MT route, or will Archivist itself be enough? I'm really not concerned about the spell availability as a raw Archivist - should I be? Are there things a Wiz gets that I would need I can't dig out of some esoteric source as a divine spell (Domains, Druids, Blackguads/Pallys, etc)?
What doth the mighty CO boards think?
EDIT: We're starting at fourth level, and the race is elf - (Pathfinder Elves: +2int, +2cha,-2 con). Due to the large stats we're being given, int will easily be 21.). Also, the DM's modified Archivist to be completly dependant on INT, so I don't need to worry about the MAD for bonus spells.
I think what I'm curious/concerned about is, will a raw Archivist have the spells per day/spell selection to cover the roles the not-mages can't? Should I try to get the Precocious Apprentice Wizard->Archivist->MT route, or will Archivist itself be enough? I'm really not concerned about the spell availability as a raw Archivist - should I be? Are there things a Wiz gets that I would need I can't dig out of some esoteric source as a divine spell (Domains, Druids, Blackguads/Pallys, etc)?
What doth the mighty CO boards think?
EDIT: We're starting at fourth level, and the race is elf - (Pathfinder Elves: +2int, +2cha,-2 con). Due to the large stats we're being given, int will easily be 21.). Also, the DM's modified Archivist to be completly dependant on INT, so I don't need to worry about the MAD for bonus spells.
If you were starting at a higher level-- 12 or higher perhaps, I would say mystic theurge would be more viable. At 4th level, you're just going into the stretch where a mystic theurge is incredibly painful to play. You might find yourself a bit short on spells as it is, but the higher level spells should make up the difference. I would consider seeing if you can pick up Leadership at 6th level instead to get a wizard cohort-- with the +2 Cha bonus you should be in good shape for the feat.
Unless you are pulling early entry shenanigans, you will be incredibly weak for the next few levels.
My plan was to do early entry via Precocious Apprentice - if my math is right that means I only drop one level of Archivist for 11 levels of Wizard. Well, and burn a feat, but in PF you get a feat every two levels instead of every three, so I think I can suck it up.
On the other hand, I hadn't thought of just picking up a Wizard cohort. That may be the easiest way to go, since the PA route feels a little cheesy, and I try to avoid cheese because it tends to smell after a few sessions.
My plan was to do early entry via Precocious Apprentice - if my math is right that means I only drop one level of Archivist for 11 levels of Wizard. Well, and burn a feat, but in PF you get a feat every two levels instead of every three, so I think I can suck it up.
On the other hand, I hadn't thought of just picking up a Wizard cohort. That may be the easiest way to go, since the PA route feels a little cheesy, and I try to avoid cheese because it tends to smell after a few sessions.
lol, Leadership is much more powerful (aka cheesy) than early entry via Precocious Apprentice. Most DMs are more likely to ban the latter than the former, in my experience, though.
You will find that the spell selection for Archivist is diverse enough that it's probably enough to cover all casting needs.
As for spells per day, my books are currently packed (I just moved) - but there's a full-progression PrC in Divine Champion that gives the Plant Domain - including the extra spell per spell level. This gives a nice little bonus. (Someone I'm sure can name the PrC - I don't remember)
The real key with any Archivist of course is to get access to all those obscure spell lists that give you the best spells at lower level. This is THE FEAT that does that. You attach it to your prayer book - and then, with a sacrifice of gold, you are getting Heal as a 5th level spell (Adept), Lesser Restoration as a first level spell (Paladin), etc. (Check out the PrC's in Book of Exalted Deeds for extremely nice spells at low levels). (Specifically - you are increasing the value of your prayer books by having spells spontaneously appear in it)
Here's where you mine for very good spells to add to your list:
1) PrC's. Many PrC's add really good spells at lower spell levels. Check out Book of Exalted Deeds for your best choices, though the Blighter is actually pretty good in this respect as well.
2) Unearthed Arcana: Specifically, the Divine Bard. Now any Bard spell can be a divine spell. Early dominate and charm entrances.
3) DMG: The Adept. Excellent spell list.
4) Domains: Any clerical domain are all divine spells, and therefore, legal to mine for archivist spells.
Giving the Archivist single attribute casting is crazy good - I wouldn't jump ship personally.
Shame is that the character is solidly neutral (due to backstory, alignment, and general getting-along-with-the-party members) and can't grab Ancestral Relic. 
My plan was to do early entry via Precocious Apprentice - if my math is right that means I only drop one level of Archivist for 11 levels of Wizard. Well, and burn a feat, but in PF you get a feat every two levels instead of every three, so I think I can suck it up.
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This does not work. There are other early entry methods but precotious apprentice does not work. This explains why better than I can:
74.125.93.132/search?q=cache:urjHc0HihBE...
Dissention even in the thread. I'd prolly rule, as a DM, that you can cast 2nd level spells with PA and RAI it does let you satisfy the entry requirements as they are written, but it's clearly not written to let you get into a prestige class two levels early. Then again, if it didn't smell a little like cheese, would anyone actually take that feat, for any reason ever? lol.
I dunno, other than being an Illumian(bleh, terrible flavor is terrible) or some stellar backflip-cheese, it seems a bit pointless - I'm not sure those three levels lost (and access to 9th level divine spells, of which you could have ANY YOU WANTED, if brain remembers right)justify the wizard levels gained.
I think I'm just going to outright ask my DM if it's legitimate rather than trying to spring it on him in a level, when I hit five and might or might not qualify for MT. Because there's no way I'm eating the three level setback to qualify for MT when my spells are just going to be there to support my primary caster class, by giving him more slots to do stuff with. I just wish MT was nearly as good as a "neat tricks you can pull with spell slots from either side" as Ultimate Magus - then it might be worth the lost spell levels.
An Archivist's power depends entirely on what spells you can cast. Since the set of legal Archivist spells is 'all divine spells', then you can legally add any spell to your Archivist list if you can get it as divine.
Numerous abilities exist to convert arcane spells to divine. "Dragon" has Alternative Source Spell. Geomancer (Complete Divine) could convert arcane spells to divine. Unerrataed Artificers can make items as arcane or divine. You don't need to have any of these abilities, but your campaign setting does so you can nab scrolls of these delicious spells.
Before you go scouring books for the lowest level versions of spells, note that someone did the work for you.
Since this is a high power game, ask your DM if secret page available at L2 via the Rune Domain lets you add a spell to your prayerbook for free with each casting.
"Secret page alters the contents of a page so that they appear to be something entirely different. The text of a spell can be changed to show even another spell."
If your DM lets you make prayerbooks for free with any spell you wish (preferably pre-game since it's better for you) then go for it! Make a small library of spell-filled prayerbooks containing every every divine spell at its lowest level. Make a backup or 4!
However, there are short-term bonuses to taking a Wizard level. One is more L1 spells. Grease, silent image, benign transposition, mage armor, mount, and shield are handy to have, even at high levels, and their DC will scale with your INT. You can swap Scribe Scroll for a Improved Initiative or a Fighter bonus feat. You can specialize for more slots and class features like Abrupt Jaunt. The big downer is a loss of long-term power- higher level class features and spell slots- but you may never get there.
As a caster, your effectiveness depends on how many helpful spells you can cast. A straight Archivist gets as many spells per day as a specialist Wizard, but until about level 5, you're stuck being very judicious with your spells. Unless you're certain this will be the last fight before resting, you can't go all out.
Since people will also look to you for healing, buy a wand of cure light wounds or lesser vigor. At level 3, get the reserve feat Touch of Healing from Complete Champion 62. Ask groupmates to each buy a Healing Belt (Magic Item Compendium). Heal between fights as much as practical.
Finally, Mystic Theurge is only viable if you enter early. Losing one level to cast from 2 spell lists is probably viable. Losing 2 levels hurts, but is probably on the low end of fair. Losing more is just crap.
Archivists are fun, I played one in a Ravenloft campaign (the setting not the adventure) loosely modeled after Dr. Rudolph Van Richten. I would forego the Mystic Thurge route and go with something like Knight of the Raven or Sacred Exorcist, both of which give you turn undead which more importantly gives you access to Divine Metamagic.
I have a fairly cheesy build that gets 18/19 casting, but it needs the bamboo spiritfolk race. If you *need* Trackless stride, and no alternatives, (i.e. Snowrunner, feat, Frostburn, as Woodland Stride through loose snow) to get into Arcane Hierophant, then you can do:
(TBH I'd far prefer using Bamboo/snowrunner, else you lose 3 (!) caster levels. If you can get something like that approved, you'd get a nice:
2 Archivist/1 wizard/7 MT/10 AH, with a 2+7+10 = 19 CL for Archivist, and 18 for wizard.
If you can get Trackless Step with 1 level, you can use the same type of build, with an 18/18 split.
Wizard (1/2) Archivist (1/2) Druid 2 Mystic Theurge 5, Arcane Hierophant 10.
With this style progression:
(level/class (1st letter of each word)/wizard CL/Druid CL/Archivist CL (More with prac. caster)/Feats *needed*/equivalent CL of 20 caster.
1W 1 0 0 Prec. App (wiz) 1
2A 1 0 1 - 2
3D 1 1 1 Prec. App (Arch---Or Alt source spell---) 3
4MT 2 1 2 - 4
5MT 3 1 3 - 5
From here on- format is LEVEL(CLASS) Wiz/Arch/Druid/20caster
6MT 4/1/4/6
7MT 5/1/5/7
8MT 6/1/6/8
9D 6/2/6/9
10MT 7/2/7/10
11AH 8/2/8/11
12AH 9/2/9/12
13AH 10/2/10/13
14AH 11/2/11/14
15AH 12/2/12/15
16AH 13/2/13/16
17AH 14/2/14/17
18AH 15/2/15/18
19AH 16/2/16/19
20AH 17/2/17/20
Same rules as above for format, but assuming you find a way to get trackless step in 1 level:
D=Trackless Step level
1W 1 0 0 Prec. App (wiz) 1
2A 1 0 1 - 2
3D 1 1 1 Prec. App (Arch---Or Alt source spell---) 3
4MT 2 1 2 - 4
5MT 3 1 3 - 5
From here on- format is LEVEL(CLASS) Wiz/Arch/Druid/20caster
6MT 4/1/4/6
7MT 5/1/5/7
8MT 6/1/6/8
9MT 7/2/7/9
10MT 8/1/8/10
11AH 9/1/9/11
12AH 10/1/10/12
13AH 11/1/11/13
14AH 12/1/12/14
15AH 13/1/13/15
16AH 14/1/14/16
17AH 15/1/15/17
18AH 16/1/16/18
19AH 17/1/17/19
20AH 18/1/18/20
Finally, if you can get it without ANY levels, as above, but add 1 to every caster level after level 3 for the '2 level' base (i.e. 2 arch 1 wiz) and enjoy the benefits of 1 class casting as a sorc with -1 CL, and the other side casting as a wiz with LA 2.
BTW, I'm assuming feats are 1/3/5/7/9 etc.
Enjoy.
EDIT: Oh, and if your DM is a loony, you can probably find a homebrew domain (www.giantitp.com/forums/showthread.php?t...) that gives trackless step, and a feat to give you it (www.dandwiki.com/wiki/Domain_Wizard_(DnD_Alternate_Class_Feature) Poorly phrased, but suitable if you can get it.) :P
Further than that, all I can suggest is that if you are the sole caster, the ludicrous number of spell slots you can get should be worthwhile, specialising as a wizard *may* be worthwhile depending on if you can hold up the rest of the spells with archivist, (Normally it is *always* the best, but you have the fantastic generalist wizard alternative feature.
Arcane Hierophant tricks are neat, but not sure how well that works with Archivists since it requires trackless step as a class feature, not racial or feat based. There is similar fun with wildshape classes if you are allowed to use the Divine minion template to qualify despite not being level based (ECL 3 Master of many forms anyone?). A nice Druid 2/ Wiz 1/ Druid 1/ MT 1/ AH 10/ MT 5 is great too.
Anyway, a few things no one has mentioned. In pathfinder, at least according to the PrC download (unless it was updated after the book went to press), mystic theurge at level 10 allows you to cast a spell off of both spell lists. Second, the skill requirements were dropped to skills of 5. You can see where this is going. My favorite early entry is with versatile spell caster, but it requires you to be a spontaneous caster.
Beguiler or similar 1/ Archivist 1/ Mystic Theurge 10
With versatile spell caster you can prepare a second level spell with 2 level 1 spell slots. Beguiler automatically knows all the spells on its list and the archivist just needs a book with a level 2 spell in it. Not as versital as the wizard combo, but that will get you dual casting pretty quick. Dreadnecomancer or warmage will work as well, but Cha based.
But as stated by many above, any arcane spell can be converted to a divine spell and the archivist gets all the divine spells. So regardless of what you do, you can already (with some work) get any spell in the game with the archivist alone. Leadership can be used for a warlock as well, which can craft any scroll just like an artificer. So it really depends on if you want that extra casting pool or a PrC that gives you something else.
Hmm, how about
Dread Necromancer 1/Archivist 1/Mystic Theurge 3/ Dwenomer Keeper 10/Mystic Theurge 6
L1 Versatile Spell Caster, L3 Craft Scroll, L5 Extend Spell, L7 Persistent Spell, L9 Divine Metamagic
Dread Necromancer will give you turn undead for divine metamagic fun, while Dwenomer Keeper will allow you to convert spells to supernatual abilites (no xp or material costs) and lower your metamagic feats by one level.
Only... 5 ranks?
Elf, 1 flaw.
1Wizard Alternate Source spell + 4 ranks knowledge + Prec. A.
2Archivist finish the skill ranks.
From here its mystic theurge.
3 Apprentice feat. See DMG2. Make survival you're class skill.
4
5 Endurance feat
6
7
8 Ranks in:
Hide 5 ranks, Knowledge (nature) 5 ranks, Move
Silently 5 ranks, Survival 8 ranks.
9 Take a level of wildrunner: (races of the wild). It comes with trackless step and +10% movement.
levels 10-20 are AH.
You get 18/18 caster level, 1 CL behind for 1st 8 levels, 2 for remainder.
Other option is
1 wiz
2 arch
3-13 MT
14 WR
15-20 AH.
Same CL, but 1 level behind for 1st 13 levels, 2 for next 7.
Another opion would be to use 'Holt Warden' from CC. it takes 3 levels, but advances divine: 19th level divine, 16th level arcane. I'd personally be leaning towards wildrunner from RoTW.