As the number of participating countries has increased over time so too has the tournament structure. Until 1978 the finals were limited to 16 teams but since then the qualifying process has changed significantly and there are now three routes to the World Cup finals. In addition to the automatic places available in Concacaf and Africa, a place through the inter-confederation play-off is also possible for North America, Oceania, Asia and South America.
In a change to previous processes the first round of qualification in 2026 saw 54 teams drawn into nine groups with 6 teams each who played home-and-away matches on a hexa-format. The top two in each group qualified for Qatar. The remaining 12 teams are then split into three groups of four where they will play each other twice and the best two in each group will advance to the second phase.
The next stage of qualification is where it gets complicated. The 14 group winners from Nations League A through to D have been ranked according to their FIFA World Ranking. The top two in each of those groups qualify for the World Cup while the other teams go into an inter-confederation play-off.
Typically the tiebreakers in knock-out qualifiers are based on head-to-head comparison and goal difference, but they can also include a penalty shootout if needed. Many of the matches are played over two legs, and if the scores are level after 90 minutes extra time is then used and, if necessary, penalties.