Common traits

Superheroes most often appear in comic books, and superhero stories are the dominant form of American comic books. After success in the printed community, superheroes have also been featured in radio serials, novel, TV series, movies, and other media. Most of the superheroes who appear in other media are adapted from comics, but there are exceptions and changes are common.
Marvel Characters, Inc. and DC Comics share ownership of the United States trademark for the phrases "Super Hero" and "Super Heroes" and these two companies own the vast majority of the world’s most famous and influential superheroes. Of the "Significant Seven" chosen by The Comic Book in America: An Illustrated History (1989), Marvel owns Spider-Man and Captain America and DC owns Superman, Batman, Wonder Woman, Captain Marvel and Plastic Man. Like many non-Marvel characters popular during the 1940s, the latter two were acquired by DC from defunct publishers.^[5] However, there have been significant heroes owned by others, especially since the 1990s when Image Comics and other companies that allowed creators to maintain trademark and editorial control over their characters developed. Hellboy and Spawn are some of the most successful creator-owned heroes.

• Extraordinary powers and abilities, relevant skills and/or advanced equipment. Superhero powers vary widely; superhuman strength, the ability to fly, enhanced senses, and the projection of energy bolts are all common. Some superheroes, such as Batman, Green Arrow, Hawkeye and the Question possess no superhuman powers but have mastered skills such as martial arts and forensic sciences to a highly remarkable degree. Others have special weapons or technology, such as Iron Man's powered armor suits, Thor's Weather manipulating hammer, and Green Lantern’s power ring. Many characters supplement their natural powers with a special weapon or device (e.g., Wonder Woman's lasso and bracelets, Spider-Man's webbing, and Wolverine's adamantium claws).
• A strong moral code, including a willingness to risk one's own safety in the service of good without expectation of reward. Such a code often includes a refusal or strong reluctance to kill or wield lethal weapons.
  

  

  America's Best Comics/7 October 1943
• A motivation, such as a sense of responsibility (e.g. Spider-Man), a formal calling (e.g., Wonder Woman), a personal vendetta against criminals (e.g. Batman), or a strong belief in justice and humanitarian service (e.g. Superman).
• A secret identity that protects the superhero's friends and family from becoming targets of his or her enemies, such as Clark Kent (Superman), or to protect themselves from getting arrested by the police, like Spider-Man, although many superheroes have a confidant (usually a friend or relative who has been sworn to secrecy). Most superheroes use a descriptive or metaphoric code name for their public deeds. However, some superheroes, such as those of the team the Fantastic Four, eschew secret identities and are publicly known or even celebrities. There are also rare ones whose true identities are common public knowledge, even with a costumed identity (e.g. Iron Man and Captain America).
• A distinctive costume, often used to conceal the secret identity (see Common costume features).
• An underlying motif or theme that affects the hero's name, costume, personal effects, and other aspects of his or her character (e.g., Batman wears a bat-themed costume, uses bat-themed gadgetry and equipment and operates at night; Spider-Man can shoot webs from his hands, has a spider web pattern on his costume, and other spider-like abilities).
• A supporting cast of recurring characters, including the hero's friends, co-workers and/or love interests, who may or may not know of the superhero's secret identity. Often the hero's personal relationships are complicated by this dual life, a common theme in Spider-Man and Batman stories in particular.
• A number of enemies that he/she fights repeatedly. In some cases superheroes begin by fighting run-of-the-mill criminals before supervillains surface in their respective story lines. In many cases the hero is in part responsible for the appearance of these supervillains (the Scorpion was created as the perfect enemy to defeat Spider-Man; and characters in Batman's comics often accuse him of creating the villains he fights). Often superheroes have an archenemy who is especially threatening. Often a nemesis is a superhero's doppelganger or foil (e.g., Sabretooth embraces his savage instincts while Wolverine tries to control his; Batman is dark, taciturn, and grim, while the Joker is colorful, loquacious, and flamboyant).
• Independent wealth (e.g., Batman or the X-Men's benefactor Professor X) or an occupation that allows for minimal supervision (e.g., Superman's civilian job as a reporter).
• A headquarters or base of operations, usually kept hidden from the general public (e.g., Superman's Fortress of Solitude or Batman's Batcave).
• A backstory that explains the circumstances by which the character acquired his or her abilities as well as his or her motivation for becoming a superhero. Many origin stories involve tragic elements and/or freak accidents that result in the development of the hero's abilities.

Many superheroes work independently. However, there are also many superhero teams. Some, such as the Fantastic Four, DNAgents, X-Men, and The League of Extraordinary Gentlemen, have common origins and usually operate as a group. Others, such as DC Comics’s Justice League and Marvel’s Avengers, are "all-star" groups consisting of heroes with separate origins who also operate individually, yet will team up to confront larger threats. The shared setting or "universes" of Marvel, DC and other publishers also allow for regular superhero team-ups. Some superheroes, especially those introduced in the 1940s, work with a young sidekick (e.g., Batman and Robin, Captain America and Bucky). This has become less common since more sophisticated writing and older audiences have lessened the need for characters who specifically appeal to child readers. Sidekicks are seen as a separate classification of superheroes.
Although superhero fiction is considered a form of fantasy/adventure, it crosses into many genres. Many superhero franchises resemble crime fiction (Batman, Punisher), others horror fiction (Spawn, Spectre) and others more standard science fiction (Green Lantern, X-Men). Many of the earliest superheroes, such as The Sandman and The Clock, were rooted in the pulp fiction of their predecessors.
Within their own fictional universes, public perception of superheroes varies greatly. Some, like John Cunningham and the Fantastic Four, are adored and seen as important civic leaders. Others, like Batman and Spider-Man, are met with public skepticism or outright hostility. A few, such as the X-Men and the characters of Watchmen, defend a populace that almost unanimously misunderstands and despises them.