Nuisance Hazard (Levels 1–4)
Giant spiders weave thick, sticky webs across passages and at the bottom of pits to snare prey. These web-filled areas are Difficult Terrain.
A creature that enters a web-filled area for the first time on a turn or starts its turn there must succeed on a DC 12 Dexterity saving throw or have the Restrained condition. As an action, a creature Restrained by the webs can try to escape from them, doing so with a successful DC 12 Strength (Athletics) or Dexterity (Acrobatics) check.
Each 10-foot Cube of webs has AC 10; HP 15; Vulnerability to Fire damage; and Immunity to Piercing, Poison, and Psychic damage.