Props

1 10' piece of 1/4" soft copper tubing packaged in a roll. (For cost savings, buy the 20' roll and halve it.The cost difference between the 10' and 20' roll is usually small, and you will end up with two game pieces.)
 

1 40'-60' rope,webbing, chalk, or whatever will work to create a medium-sized circle boundary.
 

1 large ring (and/or an assortment of different-sized rings for the variations).You could use a Styrofoam wreath (found at any crafts store), or use a large loop of rope. Pool rings also work well and are easy to find.
 

8 generous lengths of yarn or string.

Setup

Make a large circle and place the raised copper tubing in the center. (If you are using the rolled tubing, this is easy: Simply step on the outside end and pull up from the center. The tubing should twist down, spiralling to the ground.)
 

Place the eight lengths of yarn/string and the ring(s) near the outside edge of the circle.