Halo 5: Guardians doesn’t support splitscreen gameplay with your friends, but you can still play online with them via Xbox Live. Follow these simple steps in order to do it:
- Start the game.
- Select Campaign.
- Choose Co-op.
- Invite friends.
- Start playing.
In case you don’t complete the team of four, AI bots will fill it, using characters based on the team you will play in (Osiris or Blue). Each of them has a specific role, like sniper, support, tank. The protagonist, Master Chief or Spartan Locke, is usually the most basic character in terms of gameplay.
Co-op mode will be as valid as single-player missions when it comes to progression, meaning you will only have to play once to unlock achievements and progress through the story.