Fortunately, the Rules of Basketball Are Pretty Plain. But Certain Rules Can Quickly Be Missed For Younger Teams. a Strong Example of This Is the Three-Second Rule About How Long an Offensive Player Should Be In the Key Before Clearing Out. If You've Told the Mates the Rules of the Game, There's a Easy Way They Won't Forget. Have the Laws Say About You. During Each Rehearsal, Spend a Few Minutes Testing Them. You Should Also Teach the Rules of the Game Throughout Exercises and Improve Them.