The Expert: Article 5.01 of the UEFA Champions League regulations states that for matches played under the cup (knock-out) system, if the two teams involved in a tie score the same number of goals over the two legs, the team which scores more away goals qualifies for the next stage. If this procedure does not produce a result, i.e. if the two teams score the same number of goals at home and away, extra time of 2 periods of 15 minutes is played at the end of the second leg. If, during extra time, both teams score the same number of goals, away goals count double (i.e. the visiting club qualifies). If no goals are scored during extra time, kicks from the penalty mark (Article 14) determine which club qualifies for the next stage.