Rules to play Curling
A target, the house, is centred on the intersection of the centre line, drawn lengthwise down the centre of the sheet and the tee line, drawn 16 feet (4.9 m) from, and parallel to, the backboard. These lines divide the house into quarters. The house consists of a centre circle (the button) and three concentric rings, of diameters 4, 8 and 12 feet, formed by painting or laying coloured vinyl sheet under the ice and are usually distinguished by colour. A stone must at least touch the outer ring in order to score (see Scoring below), otherwise the rings are merely a visual aid for aiming and judging which stone is closer to the button. Two hog lines, are drawn 37 feet (11 m) from, and parallel to, the backboard.
The hacks are fixed 12 feet behind each button; a hack gives the thrower something to push against when making the throw. On indoor rinks, there are usually two fixed hacks, rubber lined holes, one on each side of the centre line, with the inside edge no more than 3 inches (76 mm) from the centre line and the front edge on the hack line. A single moveable hack may also be used.