3-Player Split Screen in Borderlands (Xbox 360): Not Supported

Not supported. Borderlands 1 (and 2, Pre-Sequel) on Xbox 360 only support 2-player local split-screen (Horizontal / Vertical).

Options for 3 Players

• 2 Local + 1 Online: Two players on one console (split-screen) join a 3rd player via Xbox Live / System Link. Host must have Gold (360).
• 3 Consoles (System Link / Live): Each player on own console + copy of game.
• PC Version: Supports 4-player online; local split-screen via Nucleus Co-op (community tool) for 2-4 players (requires strong CPU).

Borderlands 3 (Xbox One/Series)

Supports 2-player split-screen (vertical only, performance issues). Still no 3P local.

For 3+ local co-op: Minecraft Dungeons, Castle Crashers, Overcooked 2, Teenage Mutant Ninja Turtles: Shredder's Revenge (4P local).