Tournaments are competitive events featuring professional and amateur teams from around the world. Most tournaments are divided into two separate phases: Qualifiers, where teams play against each other to grab a spot at the tournament; and the Main Event, where qualified teams play in either single or double-elimination brackets to become the tournament's champions.
Additionally, tournaments can be distributed among three main groups: Premier tournaments, or those which generally include a significant prize pool and LAN Finals broadcasted live; Minor tournaments, or those which are mostly played online-only by regional teams with a significantly smaller prize pool; and the Majors, which are three Valve-sponsored tournaments plus The International, all of which feature huge prize pools, compendiums, merchandise, and more.
Although all tournaments include a base prize pool, most premier tournaments (as well as some selected minor tournaments) increase their prize pool through the sale of tournament bundles, item sets, treasure chests and compendiums. Valve-sponsored tournaments usually include the release of special Immortal items that can only be obtained during the event by buying either the compendium or selected merchandise during the LAN Finals.
As of 2015, there is no other game featuring as many tournaments as Dota 2. The game's flagship annual championship, The International, is the biggest tournament to ever take place in esports with a collective prize pool of more than US$30 million throughout five editions.