Cover

When you’re behind an obstacle that could block weapons, guard against explosions, or make you harder to detect, you have cover.

Lesser Cover: +1 circumstance bonus to AC. Typically provided by creatures. Not sufficient to Hide.

Standard Cover: +2 circumstance bonus to AC, Reflex saves against area effects, and Stealth checks to Hide or Sneak. Can be increased to greater cover using the Take Cover action.

Greater Cover: +4 circumstance bonus to AC, Reflex saves, and Stealth checks. Gained by using Take Cover behind standard cover.

Cover is relative — you might have cover against one creature but not another. To determine cover, draw a line from the center of your space to the center of the target’s space. If the line passes through blocking terrain: standard cover. If through a creature: lesser cover. If a creature between you is 2+ sizes larger than both you and the target: standard cover instead of lesser.

If the target is entirely behind a wall, you don’t have line of effect and typically can’t target it at all.