Are the Conceal Spell and Cunning Casters feats for hiding spellcasting meant for use in a certain context, or intended for general use?

Question

I am making a liar character. He has False Priest archetype, Rashasa bloodline, Charisma pumped up as far as I could and as his first feat racial Realistic Likeness. So far so good.

Now, sometimes concealing what spell you are casting, or even that you are casting at all is tempting. So I looked for a way to do that, and found two:

• Conceal Spell has more steep requirements and slows down casting, but it looks like mechanically more beneficial.

• Cunning Caster is simpler, has easier requirements and only requires Bluff, but also has a lot of -4 modifiers that stack with each other.

I am not asking which one to choose. I am asking for context. I don't have books they came from (Ultimate Intrigue and Heroes of the Street), so I'm asking you:

Are these feats supposed to be generally available and useful? Or should they be used only within specific campaigns or together with some other set of rules? Does using them without the rest of their respective books make sense, assuming published modules that only require Core Rulebook and Monster Manual?

Official quote from authors would be highly appreciated.

Answer 1

The feats as presented in both these books are indeed for players to use. You should at least confirm with your GM that these books are valid options, but nothing about them particularly require a certain "type" of game or set of optional rules.

I do not have access to my copy of Heroes of the Street at the moment, but in Ultimate Intrigue, its feat section is clearly worded as the same sort of Feat chapter in others of the "Ultimate [X]" line of Pathfinder books. Ultimate Intrigue does contain some optional rules systems, but Conceal Spell does not utilize these systems, and functionally works well on its own.

I know from memory that the books like Heroes of the Street also present their feats as player options, sometimes around the use of alternate rules (e.g. Advanced Armor Training options). From my reading of the Cunning Caster feat itself, it does not appear to be based around one of these systems though and should work fine on its own.

As to why two different feats? Well, they certainly behave differently.

As you point out, Conceal Spell requires it be a part of an obvious conversation, whereas Cunning Spell appears to be nigh impossible unless you have a very high Bluff check and are casting against someone who is half asleep. Also, don't forget that the traditional feats for concealing spellcasting would be to combine Still Spell/Silent Spell. The Conceal Spell or Cunning Caster feats remove the need for Silent/Still spell, at a non-trivial chance at failure.

Answer 2

As Kommissar points out in his answer, these feats are not part of any special rules system and are available for every character (pending GM source restrictions). Note that due to this FAQ, using still/silent metamagics does not make your spell unnoticed.

A couple things to note:

• Conceal spell merely uses your ranks in bluff, this means bonuses to luff from feats (like the prerequisite of deceitful), traits, class abilities, and being a class skill do not apply to the DC to notice your casting. In contrast, Cunning Caster benefits from anything that increases bluff, which is more useful since it's easy to buff skill bonuses.

• Cunning Caster is actually easier to use when playing a psychic caster as -8 of the penalties don't apply to you anymore (since you don't have verbal or somatic components). Unlike Conceal Spell which only prevents people from getting a second check when using psychic magic.

Overall this makes Cunning Caster a much better choice if you're focusing on bluff already.