https://www.polygon.com/2017/9/19/16334400/final-fantasy-15-online-multiplayer-release-date

The online multiplayer expansion for Final Fantasy 15, Comrades, will be available starting Oct. 31. A new trailer released by Square Enix ahead of Tokyo Game Show debuts new footage from the mode, which takes place following the main campaign’s 13th chapter.

Up to four players will control their own custom hero, a member of the Kingsglaive army. They’ll embark upon a series of quests that are both multiplayer- and single-player-based, with each one unlocking new abilities and furthering the soldiers on their path to saving the Lucian kingdom. Along the way, characters from the main storyline will appear, including Noctis’ main boys Prompto, Gladiolus and Ignis in a future update.