Do you need a Nintendo account to play turf wars in splatoon 2?

Yes, you need a Nintendo Account to play Turf War in Splatoon 2. While you can access some features of the game without an account, online multiplayer modes, including Turf War, require you to be connected to the Nintendo Switch Online service, which is linked to your Nintendo Account. Additionally, having an account allows you to save your progress and access other online features.