Both modes use the hideout radio and support the documented group size, but their network and account requirements differ.
Use local wireless when the participating Switch 2 systems are together. Use online play when the players are remote. Both are selected at the hideout radio after the host finishes the first three raids, and Nintendo lists two to four players.
Local wireless is not split-screen. It connects nearby systems directly through Nintendo's local session flow. Online play routes the session through Nintendo's online services and can add account, subscription, parental-control, and network requirements.
Do not mix the two room types: a host creating local wireless cannot be found through the online join menu, and an online host is not a local-wireless room. If a nearby group cannot see the host, have every system back out and choose the same connection type.
Nintendo's documentation does not establish one-copy GameShare for this title, so this page does not promise it. Confirm ownership and access on each participating setup before planning a session.
Sources
QUICK ANSWERS
Questions players ask next
Does Splatoon Raiders have split-screen?
Nintendo documents local wireless and online play, not same-screen split-screen.
Which mode should nearby players use?
Local wireless, with each supported system joining the same local session.
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