During the regular season, overtime is a five-minute, four-on-four (four skaters, one goaltender) sudden death period, in which the first team to score a goal wins the game.

In the playoffs, however, a 10-minute, four-on-four sudden death period (20 minutes in the final) is played to determine a winner.

In the regular season as well as the playoffs, if both teams are tied after the overtime period, penalty shots ensues.

In the continuation group, the two worst teams have to play in a relegation-and-promotion playoff series to stay in J20 Nationell for the next season and avoid relegation to the second-tier league J20 Elit.

The J20 Nationell season is divided into a regular season from mid-September through the beginning of March, where teams play each other in a predefined schedule; and the playoffs starting in March and ending in the beginning of April, which is an elimination tournament where two teams play against each other in order to advance to the next round.

Based on geographical location, the 20 teams are divided into two groups: Norra ("North") and Södra ("South").

The two worst-ranked teams from the continuation group have to play in a relegation-and-promotion playoff series against the two winners from the second-tier league J20 Elit in order to qualify for the next season of J20 Nationell.

In the pre-qualification games as well as the quarterfinals, two teams battle to win a best-of-three series in order to advance to the next round.

At the end of the J20 Nationell playoffs, the Swedish Junior Champions are awarded the Anton Cup.