There are two teams. Someone from either team tosses the small "target" ball. Then both teams try to roll their balls such that their team is closest (sorta like horshoes).
The Scottis version (name escaps me right now) is similar but the game balls are weighted on one side. Experts can put 'english' on the ball, then.
To answer m'lady's question: I would think you would use the pt lumber as a frame and fill the playing area with good topsoil, several inches deep. Get it level. Water everyday for several days to let it settle. Then seed with a fine lawn fescue.