The game of soccer is played over 90 minutes, dived into two 45 minute halves. Unlike many other sports, when a foul, injury, or other stoppage in play occurs the game clock does not stop. Instead the referee keep track of how much time has elapsed during the “stoppage” in play and then they add it on to the end of that half. For example, if an injured player requires attention on the field for 3 minutes before play can resume the referee would announce shortly before the end of the half that there would be a minimum of 3 additional minutes. Time is always kept by the referee and it is up to their discretion to end the half after they determine the correct amount of time has passed.
Halftime is a 15 minute period dividing the games two halves. Players may leave the field, receive treatment, hydration or instructions from their coach/manager during this time period as it is largely unstructured. As soccer is a game of near continuous running, this is often a welcome break fro players and for fans who may need a bathroom or snack break. Once the teams return from halftime they also switch ends of the field to ensure that neither team has an unfair advantage.
As mentioned during the How to Play section most games can end in a tie if the score is level at the end of the 90 minutes plus any additional stoppage time that may be added on by the referee. However, if they game is level in a knockout tournament where a winner must be determined then the first tiebreaker is called extra time. Two 15 minute halves are played, almost like a mini game after the game where there is a halftime where the teams switch ends. However, in extra time their is no break for halftime, only enough time for a quick sip of water and for the teams to switch ends. Currently there is no golden goal like there has been in the past, where the first team to score wins, so once extra time starts both teams must go the distance and play the full additional 30 minutes.
If the scores are still even at the end of this period of play then the final tiebreaker is a penalty shootout, where both teams take turns taking penalty kicks ( a description of what a penalty kick is can be found here) until there is a winner. Each team must take a minimum of 5 kicks, and at 5 if a team is ahead then they have won. If teams are even on kicks then the shootout continues until one team leads after both teams have had their turn in a round of the shootout. These are, quite obviously, very tense affairs but can also be incredibly exciting. A rare event but certainly an exciting one!