My thoughts on the psychic's Counter Thought.

I currently have a level 7 Swashbuckler Arche-Psychic. (Archetype through bonus feats on every even, that can only be arche.)

So, I was considering what to grab for level 8 (probably a month or six of sessions before it happens).

Once again, I looked at Counter Thought. I considered it at a low level but deemed it useless for my plans.

But looking at it again, it is still useless for my build.

Still, this prompted me to actually dive into how useful I think it could be.

First up is what it does.

https://2e.aonprd.com/Feats.aspx?ID=8311&NoRedirect=1

It allows a reaction to expend a spell slot to counter a foe who is casting a spell. The spell to be countered must have the mental tag, and the spell slot expended must be able to cast a mental tag spell.

An arche-psychic (like any arche-caster) at level 20 can have all 3 feats of spellcasting, giving them 1 slot of each level up to 8th. That means eight known spells, and three of them are signature spells.

A full psychic at level 18 will have 2 spell slots of each level up to 9th. That means a total of eighteen known spell, and nine of them are signature spells. They can also pick up Conscious Spell Specialization to have an additional spell slot of each rank up to 5th, for 5 more spell slots that can only cast conscious mind spells. Depending on interpretation, these may also provide an additional five known spells, or not. Also, since they must be used for conscious mind spells, the slots may not be permitted to expend on Counter Thought.

Just on the occult (psychic) spell list, there are 140 spells with the mental tag... not counting rank 10.

Of all (non-focus, non-cantrip, rank 9 or below) spells, there are 162 spells with the mental tag.

For both psychics, setting one mental tagged spell as signature means all spell slots are available to use for Counter Thought.

But for reference:

Arche-Psychic - Maximum 8 known mental spells.

Psychic - Maximum 18 known mental spells... maybe 23.

That is out of 140 occult spells that they could know.

There are also 22 that they cannot know.

Consider... how do you know you can counter?

Under lax rules, the GM will tell the player if it has the mental tag and allow them to therefore counter it. Perhaps waving it with, 'as a psychic, you can feel the mental aspect of the spell.'

However, what about strict rules? Technically, the character needs to identify the spell to know the structure, and therefore to know if it has the mental tag.

There are two ways to identify a spell:

- Have prepared the spell in a spell slot for that day (even if already spent), or have the spell in your repertoire. This allows automatically identifying the spell, including the rank it is heightned to (spell slot spent).

- On the character's turn, make a Recall Knowledge check against the spell's manifestations. If the character did not witness the spell being cast, they must instead make an Identify Magic check. (This means Recall Knowledge can be used on a spell that was instant, if they saw it when cast.)

What does this mean for a pyschic?

Under strict rules, to counter a mental spell they must do so while a creature is casting a spell with the mental trait, and also identify it to know it has the mental tag. In other words, they can only counter spells they have in their repetoire. This means, they have an 18 (or 8) in 140 to be able to counter the spell... and there are 22 spells that they can never counter.

That means, under strict rules, that Counter Thought is a low-payoff for a full psychic, and unlikely to come up at all for an arche-psychic.

Of course, under lax rules of not needing to identify a spell to know it has the mental trait, then this becomes reasonable for either psychic.

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I'm pretty sure most GMs would go with the lax rules, so it actually has a chance to maybe be useful. And I'm sure my GM would also go by the lax rules. And if I was a GM, that's how I would rule it.

However, if I go with my rules lawyer approach to RAW... technically the strict rules would be the correct interpretation based on the mechanics of identifying spells. You don't get to know anything about a spell unless you identify it or Detect Magic. And Detect Magic doesn't give you any traits... just rank/level (heightened 3) and rough location (heightened 4).