In order to lower the number of matches to be played, this edition of the Campeonato Carioca faced another change in format and regulations.
The competition format suffered several alterations in each stage, in order to minimize the number of matches to be played.
The relegation play-offs, Taça Independência and Torneio Extra were scrapped, and the main phase will be played in a single round-robin, instead of a double one.
The winner of the preliminary stage qualified for the main phase of the competition while the remaining five were relegated to the 2021 Série A2 (the second tier being rebranded from B1 to A2).
[4] America, Americano, Cabofriense and Friburguense were the four lowest placed teams in the 2020 Campeonato Carioca main tournament.