I don't really see what the issue is. My players have always learned additional information through checks etc.
I have no problems whatsoever with "it's a check". That you're given check DCs is good. That different monsters use different skills is great.
But codifying when and how you get to make these checks is a complete failure.
If they just said "use these skills and these checks" that'd be fine.
But they could not resist making it an action to use in the three-action system. And then adding lots of niggly little feats and even spells (and a
whole class!) that grant you extra such checks.
This is an entirely unnecessary layer. And frankly, an unwelcome one.
You can even read the rules to not allow sitting back home reading up on monsters! (The Recall Knowledge check is an action. You take actions in Encounter Mode.)
First off, encounters are won or lost in maybe three combat rounds. Spending an action to gain
one nugget of information is bad enough, but remember: you likely have less than 50% chance of success on Recall Knowledge. Why? Because it's when the monster is higher level than you the situation is dangerous, and it is when the monster is higher level than you that knowing weaknesses and resistances is critical!
Spending one action to learn something, failing, and then spending one or two more actions...
and still learning nothing is plain bad game design. It's frustrating, random and unfun.
Then, asking the GM to come up with these nuggets in the blink of an eye is
unreasonable. No GM knows every monster by heart! (And don't get me started on the rulebook insisting you come up with false info on a critical failure. You tell me how fun you feel it is when the rules tell you to improvise on the spot!)
Then you have the borderline incomprehensible feats, where you ask yourself - is it supposed to be impossible to use Recall Knowledge in these situations if you don't have the feat. But if you don't need the feat, what is the feat for?!
I'm getting the impression this info juggling was meant to be an important and interesting subsystem... but we only get half of it, and not the other half, to govern what nuggets to give out.
And even that doesn't answer a big concern of mine. Nobody wants to remember which character knows what metagame info about what creatures. By that I mean the system completely fails to take into account the simple fact that as you play the game, you learn and remember how common monsters work. Asking a player to keep wasting valuable combat actions on stuff he or she already knows is just plain unworkable.
And even that doesn't answer my biggest concern...
I don't want to.
What I want, is for characters to use library research and the like, and me then reading something coherent and atmospheric. The monster's entire description. Lore from Pathfinder wiki! That sort of info. But I want to do this when everything's calm and quiet - when the players are able to focus on the storytelling.
I don't want to machine-gun random snippets of info at them during combat.
And if we're talking machine-gunning info, don't get me started on the feats and spells. What am supposed to do with "I'm using this feat or casting this spell. Now let me do five Recall Knowledge checks in a single action... okay, four successes, what do I learn?"
Recalling information is not a casino game.
5e doesn't have any rules for identifying monsters. The DM can let the players roll whatever they feel is necessary of course.
In 3.5 knowledge checks are not an action at all. The same in 4e. In both you would just roll at the start to see if you know what the creature is.
Yep. And there's nothing broken here that PF2 needed to fix.
But fix it they did, but only by adding a whole garbage heap of unwanted stuff. Look at the above - I have so many questions! And worst of all, I
know I don't need any of it to successfully GM!
So let me reiterate:
A recall knowledge subsystem of this complexity should have been relegated to a supplement, with something much simpler in the CRB.
My personal preference would be for the rulebook to say this
and only this:
Recall Knowledge is the way you justify your character knowing about a monster - its habits, strengths, and weaknesses. The Games Master decides when and where you can use this activity. The GM also decides if you learn something automatically, or if you need to succeed at a Recall Knowledge check.
If and when you're asked to make a Recall Knowledge check, the GM sets the check DC. Most often, based on the monster's level. The monster's type determines which skill or skills to use. [Insert table 10-7 here]
When you stumble upon a monster, some GMs will tell you what you want to know for free. Others will ask for a monster knowledge check, and base the amount of information on your result. Yet other GMs will have you rely on trial and error, unless you come prepared (studying monster books back at the inn, or visiting dusty libraries...)
Some GMs might even want to codify your RK usage - asking you to spend an action for each single nugget of info. See the variant rule in the GMG for one possible mechanism.
There are no feats or spells related to Recall Knowledge in the CRB in my scenario. They're all printed next to the Recall Knowledge variant of the GMG (or wherever).
I hope that answers your question ("I don't really see what the issue is.")
