What are Sidekicks, and can I use them in every Fortnite experience?

Sidekicks are friendly cosmetics that stay by your side. Bring a Sidekick with you into Fortnite Battle Royale, Fortnite Save the World, Fortnite Festival (your Sidekick will stay backstage), LEGO® Fortnite, and developer-made experiences (Sidekicks can only tag along with you if the Island Developer has enabled Sidekicks in their island).

Sidekicks do not provide any gameplay advantage and don't take damage. They react to the world around you, and you will be able to interact with them through Sidekick Emotes. 

For more information, please refer to Fortnite Sidekicks: Tail-ored to You! (Opens in a new tab) blog.