Sometimes a player wants to be a real specialist in a specific field, and the GM doesn’t want them to be hitting higher DCs when they take 20.
Any character with one or more ranks in a Knowledge skill may take this quirk in place of a favored class bonus. This quirk may be taken more than once. Each time you select this quirk, select one use of one Knowledge skill you have at least one rank in. For example, identifying undead (using Knowledge Religion), or knowing current rulers and their symbols (using Knowledge nobility). When making that skill check for that specific purpose, roll an additional d20 and use the result higher d20 rolled.
When you take this quirk multiple time you can either apply it to the same use (gaining multiple d20s you roll, always taking the highest single result), or apply it to a new specific use of a specific Knowledge skill. You cannot apply this quirk to a skill more than once per rank you have in that skill.
A character who has taken this quirk 5 or more times is generally acknowledged as a sage.