| Pizza Lord |
Quote:
Web spinners can create sheets of sticky webbing up to three times their size. They usually position these sheets to snare flying creatures but can also try to trap prey on the ground. Approaching creatures must succeed on a DC 20 Perception check to notice a web; otherwise they stumble into it and become trapped as though by a successful web attack.
Pretty much Perception DC 20 when you're right up on it and about to walk into it. Someone stopping and scanning an area likely has modifiers for distance and lighting.