[3.P] What material and tactics do you consider high op and theoretical op?

[Endarire]

I know that these terms may vary by game. Let's assume we're playing a 'typical' game (defined loosely) where (nearly) infinite loops are banned. Things otherwise work according to the RAW, including the latest errata. Official FAQ entries will be ignored, and I will assume that all disputed material will take the most powerful interpretation implied by the rules.

Let's also do 4 checkups, at ECL1, ECL6, ECL11, and ECL16, to determine how things change. A Psion6 going for Beholder Mage is a non-issue at ECL6, but possibly significant at ECL11 (Psion6/Beholder Mage2/Cerebremancer3) since he has L5 spells and powers. At ECL16 (Psion6/Beholder Mage2/Cerebremancer8), it's slightly ahead of the curve, casting L9 spells when "normal" people are casting L8 spells.

[WinWin]

At the lower end of the spectrum. Kind of amusing though.

Celestial Curbstomping.

Knockback, Dungeoncrasher and flight. Can be combined with Awesome Smite or Knockdown. Can be obtained by around ECL 9, becomes a problem at higher levels when iterative attacks and the benefits of size come into play on a DMM persisting ordained champion. Very nasty if Robilars Gambit comes into play, but what do you expect rom an 18th level character?

Flies above most enemies and knocks them into the ground, repeatedly. Airborne opponents are going to get knocked 'prone' and fall. They fall over and can't get up without being slammed into the ground again.

Think of this as an appetiser. It has nothing on a Dweamorcheater...

[Eloel]

At L1 you get Pun-Pun. Theory.
Also at L1 you get Fell Drain Sonic Snap with Prec. Apprentice (or Practical Metamagic). Highly-Optimized

[WinWin]

Though you mentioned infinite loops, there are quite a few optimization excercises that have arbitrarily large numbers involved, without going recursive.

An example would be stacking symbiotes with a poison attack and casting Venomfire/Buffing via Share Spell. The H.I.V.E was another example that uses large, but measurable (providing you have an extensive understanding of maths) numbers. Sorry I can't credit the authors of those op excercises.

An example of looping would be the commonly known Wishing for more wishes. Less known might be something like a combination of bloodlines + uncanny trickster + legacy champion.

High op methods of gaining high numbers are often associated with Casters. Examples like Circle Magic, bloodlines, master spellthief and derivitve CL PrC's such as Sublime Chord and Ur-Priest.

I am sure that there are posters that can extrapolate on this far better than I.

[Endarire]

I also bar nearly infinite loops; hence (nearly) infinite.

[SurlySeraph]

Pretty much anything that requires Thought Bottles is TO in my book. Same with infinite loops of any kind, especially anything involving wishing for more wishes. Finite numbers too high to deal with by any reasonable means, such as Lightning Maces abuse, Hulking Hurlers, the Word's caster level, hiveminds, etc. are the same.

I consider the "Seriously?"-level caster classes (Beholder Mage, sort of Illithid Savant, Tainted Scholar, Cancer Mage with infinite strength, Shadowcraft Mage [I'm not sure if SCM is truly as broken as I think it is; I don't get how it works, and whenever I hear something like "Shadow Miracles in 2nd-level spell slots" my eyes glaze over]) theoretical optimization. I consider the merely very, very good ones (Incantatrix, Mage of the Arcane Order, etc.) high-op.

Anything involving Dragonwrought Kobolds I file under TO. It has reasonable-ish uses like +3 to all mental stats as well as the silly uses like getting more Sorcerer casting than you have HD, but I just can't stand it.

Feral and Half-Minotaur I consider high-op teetering towards TO, though of course they're not nearly as powerful as casters can be.

Early entry I tend to consider near-TO even though it usually doesn't break things too much. Same with Ur-Priest.

Also, any means of casting in an Antimagic Field other than Invoke Magic. As above, not really all that broken, but it bothers me.

Also, anything that relies on repeated use of Polymorph Any Object is TO. Anything.