beepeearr said:
Now show me where in the rules it states that you can reach into an occupied square in the first place, and nowhere can I find that they absolutely never provoke an attack of opportunity.
Show me where in the rules it states that you cannot reach into an occupied square. In order to prevent Reach, you have to illustrate a rule that prevents Reach.
You can reach in all you want. That's what the word Reach allows. If you do so with an attack, you may or may not be AoOed depending on whether the action you are doing provokes AoOs. If you do so without an attack, you may or may not be AoOed depending on whether the action you are doing provokes AoOs.
It's the action that determines if an AoO occurs.
Reaching in, in and of itself, is not a determining factor on AoOs. The action you are performing is the determining factor.
Show me where in the rules it states that Reaching In will result in an AoO because you are Reaching In.
"Creatures that take up less than 1 square of space typically have a natural reach of 0, meaning that they cannot reach into adjacent squares."
So, if you have a natural reach of 5, you can reach into adjacent squares. If you have a natural reach of 10, you can reach two squares over.
"Space/Reach: ... The number after the slash is the creature's natural reach."
Plus, the touch spell rules allow you to touch your ally in the next square over as long as nothing blocks you (e.g. a Wall of Force). They explicitly give you the ability to reach into the next square to touch an ally.
beepeearr said:
I can give you an example of a "not an action" that would though. A reach 0 creature takes a five foot step into an occupied square to make an attack. A five foot step is defined as a "no action" action, on the action list, but will provoke an attack of opportunity in an unusual situation.
Tiny, Diminutive, and Fine sized creatures are the only Reach 0 creatures I am aware of.
They take the AoO for moving into the opponent's square as per page 149 of the PHB.
They do not take the AoO for taking a 5 foot step.
So no, you have yet to come up with an example of a "No Action" action resulting in an AoO within the rules.
There are a lot of examples of where the action you are doing with the No Action action will provoke. For example, concentrating to cast a spell on a moving horse. If you are in a threatened area, you provoke for casting the spell. You do not provoke for the No Action action of concentrating to cast on a moving horse.