Marbles
Marbles is a game that is still played by children, and since the 1950s, many variations of the game have been invented. The game played in the '50s was a simple version where the first player would roll his marble, then the second player would roll her marble to try to hit the first player's marble. Turns were taken one after another until one player finally hit the other player's marble, which sometimes took a long time. Once a marble was hit, it became the property of the player who had hit it. The more marbles a person possessed, the cooler she was to the other neighborhood kids.
Tin Tan Tommy
This game was the early version of the modern Hide 'n' Seek game. All that was needed to play Tin Tan Tommy was an empty tin can and at least three players. The players would pick a spot to be "home base," which was usually a light post or section of a wall, and pick one person to be "it." One player would throw the can as hard as he could down the street and whoever was "it" had to chase after the can while all the other players ran to hide. The seeker would then search out the other players, and once he found someone, he would bang the can against the surface of the home base and yell out where he had spotted the person. When a player was spotted, she became "it." If a player managed to get to the can and bang it against home base before the seeker, that player would become safe from becoming "it" for that round.
Baseball
Baseball was around long before the 1950s and probably won't go away any time soon. Though there were plenty of organized baseball teams, most people took to playing the game in an empty park with a group of friends on the weekends, sometimes making up their own rules. It was rare to see an empty ball field on the weekends and in the summer because playing outside was the number one way for kids to entertain themselves in the '50s, and baseball was a free, fun way to do it.
Outdoor Toys
The 1950s was a decade that saw a lot of new inventions, many of them being toys and other things used for outdoor entertainment. The Hula Hoop was invented in the '50s, and kids could be seen playing outside with them, holding tournaments with the neighborhood kids to see who could keep the Hula Hoop going for the longest. The Frisbee was also introduced during the '50s and enabled people to enjoy a new activity that eventually lead to the creation of the game Ultimate Frisbee, which is widely popular throughout the United States today.