One player starts by counting to 10 at the bottom of the playground while the other players have to jump around the playground to avoid the person who is "it". The catch is that the "it" person must always have his/her eyes closed. He/she will roam around on the playground trying to tag the others. If someone gets tagged, they are the new "it".
One generally would stay on the playground, but there are occasions when he/she would jump off the playground into the sand to get from one place to another more quickly. If the "it" person hears that person running around, he/she may scream out, "GROUNDIES!". If the person who was running around on the ground gets groundies called on him/her is still on the ground, they become to new "it".
WARNING: Although this is a very fun game, it can be dangerous. Because one is jumping from one obstacle to another, hence, jumping from a slide to monkey bars, some people can really fuck up and miss, causing them to fall and get hurt, die, or even contract AIDS. Have fun playing!
Bob: Wanna go play groundies?
Jim: That would be swell!