Co-op gameplay in Bloodborne is slightly different than Souls games. Here you first need to complete a few simple tasks to be able to start with Co-op mode. Your first task is to kill the first boss: Cleric Beast
The most peculiar feature of this creature is the sound he makes, it is a very unsettling sound like cries of agony or shrieking. His appearance is almost hideous with large horns and skeletal body.
To take him down you will have to start with shooting him in the face a few times, twice with a Hunter Pistol, and 5 times with a Hunter Blunderbuss, to be precise. When he is down use the R1 attack near his face while he on his knees. For the final cruel damage, thrust your hand into his skull and rip it out, causing around a damage of 400.
An Insight is the unit of how much inhuman knowledge you have. These insights are used to get Sinister Resonant Bell and Beckoning Bells for playing Co-op. You will get you first insight as soon as you see a boss in Bloodborne. After successfully killing the boss you will get 3 more insights. You get +1 as summoned player for helping others to defeat a boss in coop and you will also get an insight for using the Madman’s Knowledge Skull item. Sometimes rats also drop insights, so keep an eye out for them.
After defeating the first boss you will be able to get into the Hunters Dream with the help of the Messengers Lanterns. Talk to the Doll if you have even one insight and get the Beckoning Bell.
The Beckoning Bell will help you get other players into your world. You will only be able to find players from the area in Bloodborne in which you are roaming. Keep in mind that only those players will be able to help you who are using the Sinister Resonant Bell bell and are looking forward to help other players.
The very first thing to keep in mind is you must have atleast 10 insights to be able to get the Sinister Resonant Bell bell. when you have 10 Bloodborne Insights, find the messenger in the fountain located at the house in the Hunters Dream. Now when you want to join someone the bell will start to resonate and you will automatic reach the host.
Players can even play a Private Co-op Match. In order to set up a private co-op match follow these steps:
Go to Settings > Network > Password matching
Both the players must set the same password