Civil War is an Event for four to six players and may take up to six months to play. The Event consists of three acts, with several scenes each (Buildup and Key Scenes, which consist of Action and Transition Scenes). In addition to scenes, the event has optional rules for troupe play, optional rules improving scene distinctions and complications, and a sourcebook. The Premium edition includes the Operations Manual, which is the game system rulebook also available in the Basic Game book.
Operations Manual: As said, this is the same OM as the Basic book. However, a random character generator, has been included. The random character generator, and an example of play, are also available on the publisher's website. If you have an iPad, I highly recommend the Premium edition over the Essentials version, which does not come with the OM. The additional cost for the OM is only six dollars on DriveThruRPG.
The scenes themselves are each only a few pages long. Rather than specific details, the description is more of an overview, pointing out various important scene and datafile distinctions. That's certainly enough to play and enjoy a scene. Including the scene distinctions is a nudge up from the Basic Game's Breakout scenes, which only mentioned datafile distinctions. Watcher character datafiles (ie. villains and their agents) are included with a scene, as is advice in running these characters. Advice is also provided if players wish to pursue the scene further. The datafiles of characters in the scene and some of the scenes will be very useful in your own events, although no index is provided if you want to quickly find this information. If you haven't already purchased the Marvel Heroic Roleplaying Basic Game, go ahead and purchase the Marvel Heroic Roleplaying: Civil War Event Book (Premium Edition). The Premium Edition's scenes are better written and the variety of scenes will be useful as models for your own adventures.
Troupe Play: The scope of Civil War is much larger than any individual hero. The optional Troupe Play rules allow players to play different heroes throughout the event. Basically, the troupe play rule is that all XP are granted to the player, not the individual heroes being played. Further discussion is made for advanced troupe play, such as players who want to play heroes on either side of the registration act.
Scene Distinctions and Complications: This optional rule makes Scene Distinctions have more impact on a scene. A player may now add a Scene Distinction and a character Distinction to his dice pool for free, so long as one is a d4 and the other a d8. The Watcher may turn a Scene Distinction into a complication by spending a die from the dice pool (eg. The Pro-Registration Protestors starts as a Scene Distinction. The Watcher spends a D10 from the Doom Pool to change this into a D10 complication).
Civil War Sourcebook: While oriented towards the Civil War, the sourcebook section has information that is likely to be used for any Marvel event. Each location or faction has a short write up, datafiles for notable characters and agents, and sometimes Unlockables and Milestones. Marvel factions are AIM, Hydra, Illuminati, and SHIELD. Key Marvel New York locations include the Daily Bugle, Avengers Mansion Ruins, Baxter Building, Ryker's Island, and landmarks of New York. Fiction Marvel locations are Atlantis and Wakanda.
Friends and Foes (watcher characters): This section has additional datafiles for addtional Marvel allies and villains. Notable ones in this and the scenes include Dr. Doom, Green Goblin, Venom, New Thunderbolts, Nick Fury, Black Widow, and AIM, Hydra, and SHIELD agents. Notes are included to upgrade them to player characters. In addition to the hero datafiles, Civil War has datafiles about forty villains and heroes. With the forty-some villains in the Basic Game's Breakout event, your heroes should be pretty busy!
Hero Datafiles (pregenerated characters): Arachne, Black Panther, Cable, Captain America, Clint Barton, Cloak, Dagger, Daredevil (Daniel Thomas), Deadpool, Doctor Strange, Falcon, Goliath, Hercules, Human Torch, Invisible Woman, Iron Man, Luke Cage, Mister Fantastic, Moon Knight, Ms. Marvel, Nighthawk, Punisher, She-Hulk, Spider-Man, Spider-Woman, Sub-Mariner, Thing, Tigra, Wasp, Wolverine, Wonder Man, Yellowjacket.