Objects you will need: 3 small plastic pools. We had a couple of blow-up pools and they did not work well! You could use a blow-up one for the end though. . . One large bouncy ball. You can find this a Walmart for about $4-5 if you don't already own one for your children. One (or more slip-n-slides), and a fairly large backyard or church lawn. Hills are fine, so don't shy away from a yard because it has hills!
Setup: 1st, 2nd, and 3rd bases are the 3 plastic pools filled with water. The slip-n-slide is then set up from 3rd base to home plate. If you have more than one slip-n-slide, connect them because you might need extra room, especially if you are going down a hill. If you are working with hills, have home to first going up the hill and 3rd to home going down the hill!
Objective: Each team member kicks the ball and runs to first base and then has to SIT in the pool. They are not safe until they have done so! They cannot run onto 2nd until that have done so, even if it is a home run! They continue around the bases until they reach 3rd, then they slip-n-slide down to home plate. If the other team throws the ball and hits them, or touches them with the ball, they are out. If they don't sit in the pool before going onto the next base they are out!
This was so much fun. We spent the first half of the night just slip-n-sliding down the hill, but the game was so awesome, we wished we had started earlier! I would also recommend, if anyone has them, also use personal floatation devices (not the arm floaties but the whole bodies ones or the little boat shaped ones) to cushion as you go down the slip-n-slide. It really does start to hurt after a while and this helps! Soap is also fun!