Universe Marvel Universe Key Characters Baron von Blitzschlag, Captain Marvel, Curt Connors, Gauntlet, Henry Peter Gyrich, Iron Man, (Tony Stark, Initiative founder and SHIELD director), Justice, Ms. Marvel, War Machine, Yellowjacket; formerly Baron Zemo, Mister Fantastic, Radioactive Man (Chen Lu), Ares, Black Widow, Doc Samson, Hellcat (Patsy Walker), Danielle Moonstar, Nighthawk (Kyle Richmond), Stingray, Thing, Tigra, Wonder Man, She-Hulk, Anthem, Aphrodite, Aralune, Araña (Anya Corazon), Armadillo, Beast, Bengal (Duc No Tranh), Big Bertha (Ashley Crawford), Bishop (Lucas Bishop), Mulholland (Mulholland Black), Calamity (James Wa), Cloud 9 (Abigail, Full name unrevealed), Commission on Superhuman Activities, Constrictor, Corona, Batroc (Georges Batroc), Beta Ray Bill, Blazing Skull (Mark Todd), Bloodstone, Elsa, Bullseye, Debrii, Doorman, Firebird, Fixer, Flatman, Gargoyle (Isaac Christians), Gibbon, Great Lakes Avengers, Green Goblin (Norman Osborn), Maria Hill, Living Lightning

The Initiative, also known as the Fifty-State Initiative is a United States federal government program designed to monitor, regulate, coordinate and train America's super heroes, forging many of them into a nation wide army.

The Initiative is built around the Superhuman Registration Act (SHRA), sometimes called the “Super Hero Registration Act.” It was the most sweeping legislation of its kind to date, The SHRA sought the registration and regulation of all confirmed or suspected super human beings; all people armed with unique or exotic technologies that simulate or approximate superhuman powers; and all masked or costumed crime fighters, regardless of whether they possessed special powers or unique technologies. While the text of the act itself refers only to the registration of actual superhumans, official were allowed wide latitude in terms of enforcement, erring on the side of inclusiveness; as such, anyone whose methods or abilities echo those of a typical super-powered hero was required to register.

The SHRA legislation was passed in response to the Stamford disaster, when a television clash between the heroic New Warriors and several super-criminals in Stamford, Connecticut caused an explosion that killed 612 civilians, including 60 school children. As public sentiment began to turn against super heroes in general, the super hero community was divided over how to respond to the SHRA. Rejecting the legislation on principle, Captain America (Steve Rogers) led an underground army of “Secret Avengers” in rebelling against the new law.