Perception

Perception is a score reflecting a creature's well... Perception. Allowing you to learn things about your enemies, allies, and any strangers you may meet.

Identifying Color Identity
At any time, in or out of combat, a character may try to identify another creature's color identity. In order to do this, you must first calculate the difficulty of the check. To do so, multiply the creature's Will, Level, and number of Colors together. Roll a d20 and add a modifier equal to your character's perception score, if higher, your check suceeds, if lower you remain clueless. You may not attempt this check multiple times on the same target unless you wait a day.

Identifying an Ability Score
At any time, in or out of combat, a character may try to identify the ability score of another creature. In order to calculate the difficulty of this check, multiply the score of the target ability times the creature's level. Then Roll a d20 and add a modifier equal to your character's perception score.

How Do I Calculate a Check Without Knowing Some of These Values Beforehand?
Mystery is a natural part of Perception checks, allow your GM to calculate the value you're up against without telling you, they will tell you whether you pass or fail.