The biggest optomizing challenge I can think of.

[KellKheraptis]

Alright, I wasn't specific enough.

How good could a human NPC character get, assuming only NPC classes and a lack of Magical items.

FEATS AND CLASS ONLY, FELLOWS

Then my previous suggestion still stands.  Adept + Planar Touchstone feat + as many Extra Spell feats as needed to get 9th level spells.

[ninjarabbit]

An aristocrat can make a decent knowledge devotion-based archer since they have martial weapons and all knowledge skills. The expert could too but they don't get martial weapons so he'd either have to be an elf, invest a feat in MWP composity longbows, or use crossbows.

[DavidWL]

Adept with Wild Cohort, Leadership, Undead Leadership, and Dragon Cohort. Oh yeah, and Obtain Familiar, and if you take a race with PLAs then snag Psicrystal Affinity as well.

This would be overpowered even on a commoner, good work.

you forgot landlord.

Shameless self bump:
Sam the Commoner

It's amusing that this topic comes up so often.  "Uber NPC Class"  "Uber Commoner".  "Uber Fighter" ... so many variations on the same theme

Best,
David

[Lycanthromancer]

<snip> "Uber Fighter" </snip>

That practically IS an NPC class.

[Akalsaris]

<snip> "Uber Fighter" </snip>

That practically IS an NPC class.

I remember in 3.0 the NPC warrior got Intimidate as a class skill, and the fighter didn't =P

[lans]

What about a party of tier 6s? Samurai, Divine Mind, Noble, Truenamer(Core+Tome for skill bonuses(No Item Familiar or Dark Speech, etc)).

I'm thinking fairly limited range of magic item effects, no using craploads of single/limited use items or PaO for +10 to a certain skill.

 Is Mage wright tier 6? Soulborn might be also, unless they fall more into low 5.

Then we can run them through a premade adventure( Worlds Largest Dungeon for example) and call it "winning D&D"

[Flay Crimsonwind]

Only problem is that truenamer is broken (and apparently in the literal sense that it doesn't work like it's supposed to).

[Havok4]

Only problem is that truenamer is broken (and apparently in the literal sense that it doesn't work like it's supposed to).

It can be semi functional if you really optimize it, this usually means applying almost all skill booster tricks to the character.

[lans]

The truenamer works fine considering what I said. I was intentionally limiting its truespeak bonuses to only core+Tome of Magic, and not using PaO, precisely to keep it down to tier 6.

So mostly an out of combat healer, which it should have some use, even with out items until level 15ish, its healing ability steadily decreases with levels sadly, with a small spike when it gets a new healing ability. If your depending on the Truenamer to stop you from bleeding to death, you had better pray he rolls really good.

Some control aspects at later levels.

And anti-sundering tech, kind of cool.