Domestic football

Most footballing nations run their own domestic competitions. The two basic types are leagues, which decide a champion through a season-long format, usually a double round-robin where every team plays the others home and away, and cups, which are short knockout competitions where a single defeat ends a team's involvement. Most countries have one major league competition and one major cup competition. Many also have a super cup, often contested by the previous year's league champion and cup winner.

Domestic football is the foundation of the rest of the club game. Continental competitions like the Champions League and the Copa Libertadores are mostly made up of clubs that qualified through their domestic leagues and cups. Global club competitions sit above the continental level: the modern FIFA Club World Cup brings together leading clubs from each confederation through continental titles and ranking-based qualification, while the annual FIFA Intercontinental Cup is contested by the six continental club champions. Almost every match played in club football, at every level of the pyramid, is part of a domestic competition first.

At the top of many countries' systems is a top-flight league of around 16 to 20 clubs, contested across a season that often runs from late summer to late spring in Europe and North Africa, or across much of the calendar year in South America, North America and parts of Asia. In most traditional football pyramids, the lower divisions are connected to the top flight by promotion and relegation — the lowest-finishing clubs in each division drop down to the one below, and the highest-finishing clubs in each lower division go up. The pyramid continues for several more tiers in the larger footballing nations, although some leagues use closed or semi-closed models without automatic promotion and relegation.

Alongside the league competition, most countries run a national cup competition that is open to clubs from a wider range of levels. The cup uses a single-elimination knockout format and is typically played in parallel with the league across the season. Many countries also run a super cup between the previous year's league champion and cup winner, although the format and timing vary and some super cups now involve more than two teams.

The strongest finishers in each country's top-flight league usually qualify for continental competition the following season. In the highest-ranked European leagues, the top four clubs are usually assured of direct Champions League entry, with extra places sometimes added through UEFA's titleholder and European Performance Spot rules. The next-best clubs may reach the Europa League or Conference League. Each country gets a different number of places, set by its confederation based on how its clubs have performed in continental competition over recent seasons. Smaller leagues generally get one place each, with the national champion taking it.

The domestic cup winner also typically qualifies for a continental place, usually one tier below where the top league finishers go. Winning the FA Cup in England, or the Copa del Rey in Spain, or any other major domestic cup, is a meaningful sporting incentive in part because it can carry that European reward. The exact rules vary by country and confederation, and some places can also be affected by titleholder rules, qualifying rounds and coefficient-based performance spots. The broad principle is still the same: domestic performance is the main route into the wider club game.