The field is whatever size you would like it to be, but preferably at least as big as a tennis court in an oval shape. The field must have a center line that divides the field in half, and there must be a small circle in the center to show where the two chasers that jump for the quaffle are able to stand. The next thing is the three hoops on each side of the field, and the middle hoop must be taller than the ones to either side of it. The hoops on either side of the center hoop should be the same size but don't always have to be, you can vary it up if you would like. There should also be a line in front of each of the teams goals that represents a line that can't be passed by the chasers, this makes it more of a challenge for goals to be scored.
I hope you enjoy your experience playing Quidditch, and if you would take the time to complete my survey it would be greatly appreciated.