I used a larger hole-saw and 1/4" plywood to make the discs. I used the knights stickers to cover up the hole from the drill bit guide of the hole saw. I sanded the edges of the discs after they were cut and painted them. They are light-weight and can handle the banging of game-play.
I look for challenges when I do a project. For this project it was definitely using the hole saw. The project was relatively simple, but the holes in the boards need to be cut the same so they line-up, so making sure the boards were together and needing to use a large hole saw was the challenge on this project. I bought new batteries for my Ryobi drill and it cut right through it.