Instructions
Decide what type of game you want to make: outdoor, fantasy, trivia, board, etc.
Choose a theme for your game that will be fun for children. If your child likes soccer, create a soccer themed game. If your child likes drawing, create a game that involves drawing.
Use your imagination. The wilder the game, the more enjoyable it will be. If you are having trouble thinking of a game, use a game that your child already enjoys and change it a little bit. For instance, you can create a new version of tag or create an obstacle course.
Prepare the game. If you are making a board game, design and decorate a game board and game pieces. Create trivia cards if necessary.
Make up rules. Decide how the game will be played, who will go first, how players will advance or lose a turn and how players will earn points.