UEFA Champions League is divided into 5 stages, preliminary, qualifying, play-off, group stage and knockout phase.The winners of preliminary can go to the qualifying.There are 3 rounds in the qualifying. Home and away system is adopted in each round, and the team with higher score can qualify for the next round. The ultimate winners can go to the qualifying.Teams of qualifying are divided into seeded and unseeded teams. Home and away elimination system is adopted in the games. The winners can go to the group stage.There are 8 groups in the group stage, and each group has 4 teams. Top 2 teams of the group can qualify for the knockout phase, and the 3rd place can participate in the UEFA Europa League. Each team has 6 games, and the team with more points will qualify for the next round. If they get same points, then the rank will be ordered by: Head-to-head records; Goals scored in away field; Goal difference; if it still equals, a drawing will be held to determine which team can qualify for the next round.There are 4 rounds in the knockout phase; they are Round of 16, Quarter-finals, Semi-finals and Final. Teams play against each other over two legs on a home-and-away basis, except for the one-match final. Final will be played in a neutral field. If a game ends in a draw within 90 minutes, then it will go into a 30-minute overtime. If the winner can still not come out, then the game will go into the penalty kick.