Sensory Conditions Detailed
Detection states: Observed (normal), Hidden (DC 11 flat check, know location), Undetected (guess square + DC 11), Unnoticed (unknown). Invisible grants hidden + DC 5 flat check.
PF2e tracks how well creatures can perceive each other using a detailed detection system. These conditions replace simple "can you see them" checks.
Observed: The default state. You know exactly where the creature is and can target it normally. Most creatures in combat are observed.
Hidden: You know the creature's general location (which square it occupies) but cannot see it precisely. You can target a hidden creature, but must succeed on a DC 11 flat check or the attack misses. The hidden creature is off-guard to you (you know roughly where they are). A creature becomes hidden from you when it successfully Hides behind cover or concealment.
Undetected: You have no idea where the creature is. You must guess which square to target (the GM may secretly tell you if you guess wrong), and you must succeed on a DC 11 flat check. Creatures that Sneak successfully become undetected. Point Out can reduce undetected to hidden for your allies.
Unnoticed: You don't even know the creature exists. You cannot attempt to target it. A creature using Avoid Notice during exploration that beats your Perception enters combat unnoticed.
Invisible: An invisible creature is automatically hidden to all observers (unless they Seek and succeed, which makes the creature hidden or observed depending on the result). Invisibility does not make you undetected by default — creatures still know your general area from sounds and disturbances. Invisibility grants concealment (DC 5 flat check) even against creatures that have pinpointed your location.
Concealed: A separate condition from hidden. A concealed creature can be seen, but attacks against it require a DC 5 flat check to connect. Caused by fog, dim light, blur spells, and similar effects. Unlike hidden, concealment does not grant off-guard.