Multiplayer mode features Public Matches and Private Matches both of which requires connecting online. 

In Public Matches, you can select Quick Join Online to be randomly matched with another player.

In Private Matches, you have two options: Join A Friend's Game, where you can use a code from a friend to join their match, or Invite Friend To Play, where you set up the match and generate a code to share with a friend you'd like to join you.

All modes feature 1on1, 1on1 with Weapons Allowed, Tag Team, and Tag Team with Weapons Allowed."