Ice hockey is played in a rink, on a sheet of ice which is approximately two-thirds the size of a football field, usually between 185 and 200 feet long and 85 feet wide. The game is played in three periods of equal length: 20 minutes for each period at most levels, but often 12 or 15 minutes in youth classifications. The sport involves four basic skills: Skating, passing, stick-handling, and shooting. These skills can be learned at any a