Tiering the Pathfinder Classes - Cleric, Druid and Wizard

[Aquillion]

I would define T0 as follows:

"Able to immediately accomplish literally anything that can be accomplished by any class, with no relevant chance of failure, regardless of whether they anticipated it or prepared for it; and capable of doing so indefinitely without need for rest or recuperation."

That is clearly beyond the capabilities of T1 classes. I don't think any published classes or options outside of extreme theoretical optimization are going to be at T0, but it establishes a clear explanation of what would eg. raise the wizard to tier 0.9 (by bringing it closer to perpetual motion without the need to rest, or by significantly expanding its ability to deal with problems that it hadn't prepared for.)

This also fits into the arc of the existing high-tier classes:

T2 can deal with anything they're built to prepare for, but can only be built to prepare for a limited list of things.

T1 can deal with anything they have prepared for, and can prepare for many things every day, changing their choices each day (which means they can do anything with a day to prepare.)

T0 is always prepared for everything at all times (which also implies never running out of spell slots or whatever other resource fuels their capabilities, if there is one.) They are the literal implementation of the "Schrödinger wizard" we sometimes discuss here, who always has the correct spell no matter what. It's the logical step beyond T1, and even though no class completely reflects it, there are clearly going to be options and archetypes that push you closer to or further from it.

eg. you can clearly, in this framework, argue that an Exploiter Pact Wizard pushes the wizard closer to T0 (always having the right spell without exception), though some people might argue that the trade-off of losing specialization spell slots (pushing you further away from "never runs out of gas") keeps its rating from changing.

I agree. Almost universally when I see people talk about T0, they mean something like "T1 or T2 but I really like it", or they're unfamiliar with the shenanigans a high-level wizard can pull and just assume that the trick they've found is better than that.

Any class can punch above its tier if it is well-optimized and played extremely effectively; that footnote has been part of the tier list since the beginning. So saying "well, a wizard can fit your definition of T0 if they always select the right spells anyway and are perfect at using magic to create opportunities to rest so they never run out of slots" is no different than saying "well, a Sorcerer can effectively be T1 if their spell selections are good enough and they exploit all the various ways of getting access to floating slots."

It doesn't change the rating of the base class, which assumes they are being played "normally."