Recall knowledge in combat

Recall knowledge is governed by the following standardisation of rules. These concern the initial identification of the creature, and then further recall knowledge actions to gain more mechanical information about the creature.

Initial Identification

From the CRB:

A character who successfully identifies a creature learns one of its best-known attributes—such as a troll’s regeneration (and the fact that it can be stopped by acid or fire) or a manticore’s tail spikes. On a critical success, the character also learns something subtler, like a demon’s weakness or the trigger for one of the creature’s reactions.

It is not possible for a character to re-attempt indentification after a failure or critical failure, following the same logic as in the additonal knowledge rules.

This is the only step of the process that allows mastermind rogues and the monster hunter ranger class feat to apply their bonuses. If a character has already succeeded at a check to identify the creature, other characters may still make further attempts.

Additional Knowledge

From the CRB:

Sometimes a character might want to follow up on a check to Recall Knowledge, rolling another check to discover more information. After a success, further uses of Recall Knowledge can yield more information, but you should adjust the difficulty to be higher for each attempt. Once a character has attempted an incredibly hard check or failed a check, further attempts are fruitless—the character has recalled everything they know about the subject.

Note that additional knowledge can only be attempted by a character who has successfully identified a creature. Good pieces of mechanical info ask about with additional knowledge are:

• Fastest speed
• Lowest defence
• Key traits eg. Mindless
• Highest resistance
• Highest weakness
• Any non-standard vision types