ESL Mobile Open 2021 Summer Thailand is part of the ESL Mobile Open series organized by ESL. The tournament will start with 4 qualifiers where two teams qualifies from each leading to the main event stage. The main event will start with a round robin group stage where top 4 teams advances to the playoffs while the rest proceeds to the last chance qualifier stage and only 1 will qualify to the playoffs. Playoffs will be played in a double elimination bracket.