Outdoor Games
Certain games are best played outside. On nice days, take your charges outside to let them run around, be active and use their energy. Decide on a game to play depending on the age group of your charges. While Hide and Seek or tag, for example, is good for older kids, Red Light, Green Light might only be fun for younger kids.
Sports
Kicking around a soccer ball or tossing a baseball back and forth might be all your charges want to do. Add variations to the usual game of catch or soccer by making up rules together. For example, if you are playing catch, add the rule that you can only catch and throw the ball with your non-dominant hand. Creating a game together forms a bond between you and your charges -- and it gives you something to play the next time you babysit.
Indoor Games
Rainy days and cold days can be a hassle for babysitters -- if the kids can't go outside, they will likely get restless and cranky. Prevent boredom by playing games indoors. Break out the board games and let each child choose his favorite. Alternatively, set up an indoor scavenger hunt and help the kids complete tasks or locate a treasure around the house.
Learning Games
Create a game that helps the kids complete and understand homework. If you are watching multiple children, create a game show-type of game in which the players have to answer questions specific to their homework assignments. Give a point for every correct answer. Award a prize to whomever has the most points at the end. If you are babysitting one child, make a matching game based on terms from his homework. Learning games will help the kids complete a required task in an exciting way.