Invite friends to a multiplayer game. Tap Friends, choose a friend, choose a game, then tap Play. If the game allows or requires more players, choose the players, then tap Next. Send your invitation, then wait for the others to accept. When everyone’s ready, start the game. If a friend isn’t available or doesn’t respond, you can tap Auto-Match to have Game Center find another player for you, or tap Invite Friend to invite someone else.
Send a friend request. Tap Friends, tap , then enter your friend’s email address or Game Center nickname. To browse your contacts, tap . (To add several friends in one request, type Return after each address.) Or, tap any player you see anywhere in Game Center.
Challenge someone to outdo you. Tap one of your scores or achievements, then tap Challenge Friends.
What are your friends playing and how are they doing? Tap Friends, tap your friend’s name, then tap the Games or Points bubble.
Want to purchase a game your friend has? Tap Friends, then tap your friend’s name. Tap the game in your friend’s game list, then tap in the upper right.
Make new friends. To see a list of your friend’s friends, tap Friends, tap your friend’s name, then tap their Friends bubble.
Unfriend a friend. Tap Friends, tap the friend’s name, then tap in the upper right.
Keep your email address private. Turn off Public Profile in your Game Center account settings. See Game Center settings below.
Turn off multiplayer activity or friend requests. Go to Settings > General > Restrictions. If the switches are grayed, first tap Enable Restrictions at the top.
Keep it friendly. To report offensive or inappropriate behavior, tap Friends, tap the person’s name, tap in the upper right, then tap Report a Problem.