Nintendo's Splatoon Raiders is marketed as a single-player game, but it does include a multiplayer mode that lets players team up with friends, despite the game offering no in-game tutorial explaining how to access it. The feature is significant for anyone hoping to team up on raids, as it changes the game's balance to include more enemies for a tougher, more chaotic experience.

To start multiplayer, players must interact with a radio located near the treasure bot on the team's ship base after completing the introductory missions, where they can set a nickname and choose between online or local wireless. Crucially, local wireless is not local co-op, as Splatoon Raiders does not support split-screen play, so nearby friends still need their own console and copy of the game. Online players can join an existing room, add friends from their console's friend list, or create a password-protected room of their own, mirroring the multiplayer system used in Splatoon 3.