There are two versions of this event, so be careful which one you pick up.
-- If you already have the Marvel Heroic Roleplaying Basic Book, then pick up the Essentials Edition. It contains only the additional rules for the Event and the Event material itself.
-- If you don't have the Marvel Heroic Roleplaying Basic Book, then pick up the Premium Edition. It contains the Rules Event-specific rules Event material itself.
The most interesting rules for this event for me are: Resolving Hero vs. Hero conflicts and Troupe Play.
Hero vs. Hero: interesting because the Civil War event does pit heroes against one another (and villains too), and while some of the rules can be chalked up to extrapolations of the framework already established, it's nice to see it stated outright -- particularly for touchy issues like having one player inflict a crippling complication on another player's character.
Troupe Play: interesting because it allows players to play more than one Hero in the course of this epic event -- important if a character is imprisoned or sidelined by injury. It also posits the option of pooling XP (wherein a player earns XP for the event instead of that player's Heroes), so that key elements of the scenes, storylines, and heroes might be unlocked regardless of the status of any one Hero.
THE EVENT PROPER
The book gives a good overview of the Civil War conflict, as well as detail on the factions involved, the key players, and locations and battlefronts that the conflict unfolds on.
In three Acts, the Civil War event is detailed with the recommended sequence of scenes and information on the recommended action and transition scenes for each. There is enough information to run each scene, though I do find myself wanting to pick up the comic books (given the immense amount of backhistory for a lot of the characters) to determine possible reactions of each one in a given scene. There is also space or leeway given to really spin the Event down different paths other than the ones in the official Marvel Universe timeline -- and I'll avoid spoilers here for those who never bothered to pick up all the comics in this mega-crossover event. There's a lovely bibliography in the back if you're interested.
32 hero datafiles in the Civil War sourcebook, with an Index that indicates where all the datafiles for the movers and shakers in the Event can be found in either the Basic Book or the Event Sourcebook -- with some of them (like Clint Barton) reflecting the various character changes and roles they played in the entire war.
Excellent material for this widescreen, multi-location, multi-front event.
Overall, the book really does make me want to get a group together to play out different factions simultaneously to put our own stamp on the Marvel Universe -- perhaps with our own characters or with key players in the event acting the way we feel they should have acted. And that's big praise from someone who really dismissed the entire event when it unfolded in comics as flawed (at best). This tome makes it engaging enough for me to want to be in the event proper and make things turn out differently, hopefully better.
(this review also appears on my blog -- armchairgamer.blogspot.com)