 The referee is responsible for keeping time, even when—as in many professional tournaments—he is assisted by an official time-keeper.If time expires while the ball is in play, the game continues until the ball is "dead", and only then will the referee blow the whistle to signal half-time or full-time; but if the referee awards a penalty or free-kick, the game continues.In the knockout stages of rugby competitions, most notably the Rugby World Cup, two extra time periods of 10 minutes periods are played (with an interval of 5 minutes in between) if the game is tied after full-time.