In the 2021 LCK Summer Split, which will commence on June 9, several rules will be changed. The roster change period, side selection, and the minimum number of games played to be nominated for the LCK awards will change.

The biggest change is that the roster change period will be reduced. Originally, roster changes were only allowed before the season, mid-season between the two rounds, and before the playoffs. Now, teams can call up or send down players every two weeks. There will also be an emergency call-up or send-down rule added for when there are player-related emergencies and that they cannot play in a game.

The side selection for the regular season has also been changed. The previous side selection was fixed where the home team plays on the blue side in games 1 and 3, but now, the home team will select the side to play on for the first game, and the losing team will pick which side to play on in the next game.

Another new rule was about the number of games needed to be nominated for the LCK awards. Players will have to play in at least 29 games (sets) to be nominated. Previously, players had to play in at least 18 games.