2016–17 UEFA Champions League qualifying phase and play-off round
The 2016–17 UEFA Champions League qualifying phase and play-off round began on 28 June and ended on 24 August 2016. A total of 56 teams competed in the qualifying phase and play-off round to decide 10 of the 32 places in the group stage of the 2016–17 UEFA Champions League.
The schedule of the competition was as follows (all draws were held at the UEFA headquarters in Nyon, Switzerland, unless stated otherwise).
In the qualifying phase and play-off round, each tie was played over two legs, with each team playing one leg at home. The team that scored more goals on aggregate over the two legs advanced to the next round. If the aggregate score was level, the away goals rule would be applied, i.e., the team that scored more goals away from home over the two legs advances. If away goals were also equal, then thirty minutes of extra time would be played, divided into two fifteen-minutes halves. The away goals rule would be again applied after extra time, i.e., if there were goals scored during extra time and the aggregate score was still level, the visiting team advanced by virtue of more away goals scored. If no goals were scored during extra time, the tie would be decided by penalty shoot-out.
In the draws for each round, teams were seeded based on their UEFA club coefficients at the beginning of the season, with the teams divided into seeded and unseeded pots. A seeded team was drawn against an unseeded team, with the order of legs in each tie decided by draw. Due to the limited time between matches, the draws for the second and third qualifying rounds took place before the results of the previous round were known. For these draws (or in any cases where the result of a tie in the previous round was not known at the time of the draw), the seeding was carried out under the assumption that the team with the higher coefficient of an undecided tie advanced to this round, which means if the team with the lower coefficient was to advance, it simply took the seeding of its defeated opponent. Prior to the draws, UEFA may form "groups" in accordance with the principles set by the Club Competitions Committee, but they are purely for convenience of the draw and for ensuring that teams from the same association are not drawn against each other, and do not resemble any real groupings in the sense of the competition.
...
Wikipedia