Perception is treated as a core statistic, comparable in importance to attack bonuses or saving throws.
While level and proficiency structures mirror Pathfinder 2e, Perception is called out separately from skills: every character has a Perception modifier, and many classes define their starting Perception proficiency (for example, some tech-focused classes begin at expert Perception).

Perception is used to:

Detect hidden or concealed creatures, traps, and environmental hazards during exploration.

Roll initiative in situations where awareness and reaction speed are what matters most.

Oppose certain actions, such as attempts to Avoid Notice, or to conceal actions and objects.

Spotting Trouble (Exploration)
When players say “I keep an eye out,” that’s Perception. It’s rolled to notice traps, hidden compartments, odd environmental clues, and invisible or hiding creatures.
The GM often rolls Perception secretly when characters Search or pass near hidden features, so players only know their characters’ experience, not the die result.

Initiative (Encounters)
In many encounters, initiative is rolled with Perception, representing who actually reacts first when chaos erupts.
Characters with high Perception often act before ambushers, which can flip otherwise-lethal opening volleys.

Opposing Stealth & Deception
Perception serves as the DC for attempts to Avoid Notice, Conceal an Object, or in general to sneak or hide.
It also supports some “read the situation” checks when you’re not drilling down into a full social Influence subsystem.