This document provides an overview of common hand signals used by referees in basketball games to communicate rulings on fouls, violations, and scoring plays. It explains signals for different types of fouls like charging, blocking, and intentional fouls. It also outlines signals for violations such as traveling, double dribble, and 3 seconds in the key. Additional signals cover free throw attempts, timeouts, substitutions, and indicating successful field goals or free throws. The hand signals allow referees to efficiently communicate rulings and updates to scores to other officials, players, and spectators during the fast-paced game.