You can play with your friends in a game they're already playing! As long as your friend has the join in game setting enabled, you will be able to join them in a game with a click of a button.
To Join Another Player
- Search for the user's username or go to their Profile page
- If that user is currently in a game and is allowing people to follow them, a Join Game option will appear on the search results or their profile page
- Click Join Game and you will be placed into the game with them