A game is played over two halves of 30 minutes (at club level) or 35 minutes (at inter-county level).
Players wear a jersey with their team colours and number on the back. Both teams must have different colour jerseys. The goalkeepers' jerseys must not be similar to the jersey of any other player. Referees normally tog out in black jerseys, socks and togs.Goalkeepers may not be physically challenged whilst inside their own small parallelogram, but players may harass them into playing a bad pass, or block an attempted pass.Teams are allowed a maximum of five substitutes in a game. Players may switch positions on the field of play as much as they wish but this is usually on the instructions of team officials.Officials for a game comprise of a referee, two linesmen (to indicate when the ball leaves the field of play at the side and to mark '45'' free kicks and 4 umpires (to signal scores, assist the referee in controlling the games, and to assist linesmen in positioning '45' frees).A goal is signalled by raising a green flag, placed to the left of the goal. A point is signalled by raising a white flag, placed to the right of goal. A '45'/'65' is signalled by the umpire raising his/her outside arm. A 'square ball', when a player scores having arrived in the 'square' prior to receiving the ball, is signalled by pointing at the small parallelogram.