NFHS high-school volleyball rules — the knowledge tested on officiating certification exams. The serve (foot faults, the toss, screening); playing the ball (the four-hits rule, double contacts and when they are legal, prolonged contact, reaching over and under the net); net faults and the centerline; back-row attacks and blocks; the libero and her restrictions; substitutions and rotations; and conduct, cards, and penalties. Rulings are stamped to the NFHS rule set and season so drift is visible. Every explanation cites the governing rule idea, names the myth or near-miss ruling that tempts officials, and ends with a portable rule of thumb. Original questions about the rules — never real NFHS or association exam items and never rulebook text. Independent practice, not affiliated with the NFHS; no certification guarantee.