In a slight variation of the classic game, players stand at a setline and take turns flicking their marbles towards a hole. In the traditional game, the players each have 10 marbles, and the goal is to have the most marbles in the hole.
For international competitions, the World Marbles Federation has set a standard for the size and color of the marbles.
According to the Complete Rules:
2.1 Both players have to use marbles of different colors to eliminate confusion.
2.3 The marbles should be made from any non-metal material and should be no greater than 16.5 mm in diameter. The referees are allowed to check abidance by these rules.
2.5 The playing ground should be arranged both horizontally and vertically as evenly as possible. The throwing line is in distance of 7.5 m from the center of the hole. The hole has to be 9 – 11 cm in diameter and minimum of 5 cm deep. There must be at least 2 m of free space behind the hole. The hole should be of round shape.
Reference– http://www.worldmarblesfederation.com
Photo- http://www.marblesgalore.com