The 2016 finalists, DR Congo and Mali, failed to qualify for this edition following their qualification losses, Mali losing 3–2 to Mauritania on aggregate and DR Congo losing to the neighbouring Congo via the away goals rule. Hosts Morocco defeated Nigeria 4–0 in the final to win their first title which made Morocco the first team to win the tournament on home soil.[3][4][5]
Following the conclusion of the final of the previous edition in Rwanda on 7 February 2016, CAF announced Kenya as the host nation of the next edition 48 hours later.[1][2][6] However, CAF decided to change the host nation on 23 September the following year due to a lack of progress with preparations[7] and open up a new tender process for a replacement team with the deadline of 30 September 2017. The countries who submitted to replace Kenya as hosts are:[8]
The Ethiopian Football Federation did not provide the government's letter of guarantee and were not considered; the CAF Emergency Committee decided on 15 October that year to choose Morocco over Equatorial Guinea.[9][10]
The qualification rounds took place from 20 April to 20 August 2017.[11]
Since Morocco had already qualified in the Northern Zone before replacing Kenya as hosts, their spot in the main phase was re-allocated to their opponents in the Northern Zone final qualifying round, Egypt.[12] However, Egypt declined to participate citing a "congested domestic calendar".[13] As a result, the spot was reverted to Central-East Zone (as originally three teams would participate including original-turned-stripped hosts Kenya), and would go to the winner of a play-off in November 2017 between Ethiopia and Rwanda, the two teams which lost in the Central-East Zone final qualifying round.[14]
The squads of the participating teams each consisting of 23 players per the tournament's regulation article 72[17] were announced by CAF on 10 January 2018.[18][19]
A total of 32 match officials (16 referees and 16 assistant referees) were selected for this edition of the tournament, of which 7 were selected to operate the video assistant referee (VAR) system in a CAF competition for the first time ever, beginning at the knockout stages.[20][21][22]
The draw for the group stage was held at Sofitel Rabat in the Moroccan capital, Rabat, on 17 November 2017 at 19:30 WET (UTC±0).[23]
The teams were drawn into 4 groups of 4.[24] The hosts Morocco were seeded in Group A. The remaining teams were seeded based on their results in the four most recent editions of the tournament: 2009 (multiplied by 1), 2011 (multiplied by 2), 2014 (multiplied by 3), 2016 (multiplied by 4):[25][26][27]
7 points for winner
5 points for runner-up
3 points for semi-finalists
2 points for quarter-finalists
1 point for group stage
Based on the formula above, the 4 pots were allocated as follows:
The top two teams of each group advance to the knockout stage.
Tiebreakers
Teams are ranked according to points (3 points for a win, 1 point for a draw, 0 points for a loss), and if tied on points, the following tiebreaking criteria are applied, in the order given, to determine the rankings (Regulations Article 74):[17]
Goals scored in head-to-head matches among tied teams;
If more than two teams are tied, and after applying all head-to-head criteria above, a subset of teams are still tied, all head-to-head criteria above are reapplied exclusively to this subset of teams;
From this stage onward, the video assistant referee (VAR) system would make its debut in a CAF competition. Extra time and penalty shoot-out were used if necessary to decide the winner, except for the third-place match where penalty shoot-out and no extra time was used if necessary to decide the winner per the competition's regulations article 75.[17]
As per statistical convention in football, matches decided in extra time are counted as wins and losses while matches decided by penalty shoot-outs are counted as draws.