A relatively smooth playing field is required, usually on dirt. A small hole is made in the center of the playing area.
Each player antes up a marble, and they are randomly scattered around the playing field.
Each player uses a large marble (called a shooter) to try to knock the other marbles into the hole (much like pool)
Players take turns shooting, and if a player knocks a marble into the hole with his/her shot, they get to keep the marble they knocked in and shoot again.
One variation is called "agate up" in which all the marbles donated must be agates. Agates a rarer and thus more valuable type of marble.
If this doesn't sound familiar, try this variation
In addition to the game of marbles, there is also a science in the naming of types of marbles.