Instructions
Turn on your PlayStation 3.
Load a game which supports multiplayer play. For example, "Call of Duty: Black Ops," "Grand Theft Auto IV" and "Resistance 3" all feature multiplayer mode.
Select the multiplayer option on the game's main menu. The exact process that each game requires to invite friends will vary for every game.
Press the button indicated on your screen to open your friends list.
Press "X" on the friend you want to invite to your game. Wait a moment for the friend to accept and join your game.