Can You Play 4-Player Co-op Campaign in Borderlands?

Yes. All main entries support 4-player co-op:

• Borderlands 1: 2-player splitscreen (console); 4-player online.
• Borderlands 2 & 3: 4-player online + 2-player splitscreen (consoles). PC: 4-player online only.

Grab three friends for the full Vault Hunter experience!