This is more of a design question regarding Paizo's 2E system in general.
Many feats are written up in the following way:
SAMPLE FEAT (one action)
Prerequisites some other feat
Frequency once per day
Requirements some condition must be metThis feat allows you to do such and such.
Sometimes, however, a feat will be written up like this:
SAMPLE FEAT
This feat grants you the DO THE FEAT action.
DO THE FEAT (one action) Prerequisites some other feat; Frequency once per day; Requirements some condition must be met; Effect You do such and such.
Unless the feat grants some kind of persistent ability or bonus in addition to the action, there doesn't seem to be any reason for choosing the latter format over the former. In other words, if the feat literally does nothing other than grant a named action, then why isn't the feat itself the action?
Is there some subtle difference between the two that I'm missing? Just curious if anyone has some insight into why one format is chosen over the other for a given feat.
As a concrete example of what I'm talking about, take a look at the vesk ancestry feat Plated Deflection. It does exactly one thing, which is to grant the action "Plate Deflection".
If there a reason why it wasn't written so that the feat itself is the action, or if there would be any difference in how the feat would behave if it were, I can't see it.
Plated Deflection, 9th level vesk ancestry feat.
The question occurred to me after I read that feat, but I didn't go back to see if any others were written that way. Maybe that one is an outlier, an editorial mistake?
Etheric, level one Borai feat, is another one.
For something simple, I generally see it where the feat itself is the action.
It is mechanically equivalent for a feat to define an action. It is also more flexible because the feat can do other things too, such as having a passive benefit in addition to the active action that it gives or being upgraded at a later date (such as the Backup Disguise skill feat that takes fewer actions to use at higher proficiency tiers).
There are a couple of other scenarios that I have seen that are mechanically different from this. One is by redefining parts of an existing action, such as Goading Feint, or by adding rider effects that happen like subordinate actions, like Tumbling Theft.
The reason that those are mechanically different is because of how they interact with the Subordinate Actions rule. If a feat is, or defines, a new action, then that action is not compatible with other activities that don't name the new action specifically. So an activity that gives Demoralize as a subordinate action wouldn't let you use Scare to Death in its place. Those are different actions and cannot be substituted for each other. The ones that take an existing action and modify it or add rider effects are compatible with Subordinate actions. An activity that gives Feint as a subordinate action would be compatible with Goading Feint. An activity that gives Tumble Through as a subordinate action would trigger Tumbling Theft.
