The official rules to Carpet Ball are available here: http://www.carpetball.net/carpetball_rules.htm
NOTE: This is my first Instructable. Please let me know if I am missing information that would have been helpful to you.
Step 1: Materials
2 - 2"X10"X25" Planks
15 - 2"X4"X25" Boards
4 - 2"X4"X30" Pressure Treated Boards
4 - 2"X4"X38" Pressure Treated Boards
2 - 12"X10' Hardi Plank Flat Siding Boards
1 - 2'X12' Outdoor Carpet
8 - 3.5" Carriage Bolts with washer and nut
Staple Gun and Staples
Rink Shank Nails
Water Sealant and brush (Thompson's works well.) As an alternative, use pressure treated lumber throughout.
Step 2: Build the Frame
The short planks form the game ends and the long planks form the sides.
The ends take more abuse from balls slamming into them so overlap the long boards over the short boards to prevent loosening over time.
Step 3: Install Bottom Boards
Using deck screws (or nails), install a 2"X4"X25" board at each foot.
The bottom edge of each of these boards should be flush with the bottom edge of the side planks.
The game surface will rest on these boards.
Step 4: Add the End Well Bottoms
Using two 2"X4"X25" boards at each end, build the bottom for the end well.
Be careful to turn these boards horizontal so that they are below the game surface.
Space them eavenly in the end space.
NOTE: For an indoor version, the end well could be solid. For example, a 12"X28" piece of plywood could be screwed in from the bottom. I designed mine this way - with these gaps - so that rain would not collect.
Step 5: Build and Install Table Legs.
Attach these to each other using deck screws.
The side plank will sit on the 30" portion, and the 38" portion will wrap up the outside of the plank.
Place each leg 3 feet from the end.
Attach the legs with deck screws to hold it together for drilling.
Drill holes and attach the legs to the side planks with the carriage bolts.
NOTE: My table was for outdoor use and the legs would contact the ground. Pressure treated wood was essential. If you are building an indoor game, use regular 2X4's.
Step 6: Install the Playing Surface
Because this table is for outdoor use, I used Fiber Cement Siding. Pressure treated plywood would also work here.
Install the Fiber Cement Siding to the boards added in step 3. Leave a .5 inch gap along both sides for rain to escape.
Step 7: Treat the Wood With Water Sealant
Step 8: Install Outdoor Carpet
Lay the carpet in place.
Wrap it around the boards at each end of the playing surface, and staple from underneath. NOTE: Pull the carpet as tight as you can. Wrinkles in the carpet will negatively effect the game.
Trim the access.
NOTE: The carpet will need to be replaced every couple years or so. Do not glue it in place. Staples at each end (and along the side if necessary) will allow you to remove it later.