Roster and war size
By default, all Clan members are in the roster for Clan War Leagues. The roster represents the pool of players who can participate in the Wars of the Season and gain rewards.
Each Season Clans can choose from two war sizes: 15vs15 and 30vs30. In Champion league, only the war size 15vs15 is available.
Clans can decide the war size at the start of each season, and it doesn’t affect their league position in any way. If Clans switch between war sizes between seasons, they will continue from the league they reached regardless of which war size they played previously.