2-Player Co-op Raids with a Friend
Co-op raids are entered as a 2-player party. Form a party in the Square, and once you're both ready, you can enter. They're run separately from solo content.
How to Form a Party
With both players online, one sends an invite and the other accepts to join the same party. The party leader chooses the raid and difficulty, and the party member checks the entry requirements and ready status. You can enter only once both players are present.
What to Check Before Entering
Check the chosen raid's Combat Power, unlock requirements and battle item setup. If entry is blocked because you're doing other content or aren't fully ready, the reason is shown on screen. The bosses and difficulties available in co-op are listed in the in-game co-op list.
Differences from Solo Content
Solo raids are entered alone. The Chaos Rift, Hell, the Abyss and Hal's Hourglass are also solo content. The Square is just a space where you can see other players; being in the Square together doesn't mean you've entered a co-op raid.
During Battle
Fight while watching boss warning areas and each other's positions. Prepare for counter and stagger patterns, and exchange what you need over party chat. Damage, rewards and abandon rules follow what's described for each raid.
If You Get Disconnected
Reconnect with the same account and check your progress. If a recovery screen appears, follow its instructions. If you can't see your progress, send a Bug Report with the time, content and symptoms.