The Asian section of the 2018 FIFA World Cup qualification acts as qualifiers for the 2018 FIFA World Cup, to be held in Russia, for national teams which are members of the Asian Football Confederation (AFC). A total of 4.5 slots (4 direct slots and 1 inter-confederation play-off slot) in the final tournament are available for AFC teams.
On 16 April 2014, the AFC Executive Committee approved a proposal to merge the preliminary qualification rounds of the FIFA World Cup and the AFC Asian Cup, which will be expanded to 24 teams starting in 2019. Therefore, the first two rounds of the FIFA World Cup qualifiers also act as qualifiers for the 2019 AFC Asian Cup in the United Arab Emirates.
Format
The qualification structure is as follows:
First round: A total of 12 teams (teams ranked 35–46) will play home-and-away over two legs. The six winners will advance to the second round.
Second round: A total of 40 teams (teams ranked 1–34 and six first round winners) will be divided into eight groups of five teams to play home-and-away round-robin matches. The eight group winners and the four best group runners-up will advance to the third round of FIFA World Cup qualification as well as qualify for the 2019 AFC Asian Cup finals.
Third round: The 12 teams (an increase from 10 for 2014) which advance from the second round will be divided into two groups of six teams to play home-and-away round-robin matches. The top two teams of each group will qualify for the 2018 FIFA World Cup, and the two third-placed teams will advance to the fourth round.
Fourth round: The two third-placed teams of each group from the third round will play home-and-away over two legs. The winner will advance to the inter-confederation play-offs.
A total of 24 teams eliminated from World Cup qualification in the second round will compete in the third round of 2019 AFC Asian Cup qualification (which will be separate from the third round of 2018 FIFA World Cup qualification), where they will be divided into six groups of four teams and compete for the remaining slots of the 2019 AFC Asian Cup. The 24 teams will consist of the 16 highest ranked teams eliminated in the second round, and the eight teams that advance from the play-off round of 2019 AFC Asian Cup qualification which are contested by the remaining 12 teams eliminated in the second round.
Already into the second round: All results and details can be found here, https://en.wikipedia.org/wiki/2018_FIFA_World_Cup_qualification_%E2%80%93_AFC_Second_Round
