Themes and motifs

Many of Seagal's films share unique elements which have become characteristic of his body of work. His characters often have an elite past affiliation with the CIA, Special Forces or Black Ops (for example, Casey Ryback in Under Siege, a former Navy SEAL, Jack Cole in The Glimmer Man, an ex-CIA police detective, or Jonathan Cold in The Foreigner and Black Dawn, an ex-CIA Black Ops freelancer.) His characters differ from those of other action movie icons by virtue of their near-invulnerability; they almost never face any significant physical threat, easily overpowering any opposition and never facing bodily harm or even temporary defeat.^[26] A notable exception is 2010's Machete, which features Seagal in a rare villainous role.

Seagal's films frequently reflect aspects of his personal life. His music appears in several of his films (for example, Into The Sun and Ticker, where he appears as part of a bar band), as does his fluency in other languages (he speaks Japanese in Into the Sun) and religion (Buddhism features prominently in The Glimmer Man and Belly of the Beast). His past as an aikido teacher is also incorporated into several films, for example Above the Law (which opens with a montage of real-life photos from Seagal's own past) or Shadow Man, where he is seen giving an aikido demonstration. Several of his films also feature prominent political messages, most notably the environmentalism evident in On Deadly Ground, which ends with a lengthy speech in which Seagal (playing ex-CIA firefighter Forrest Taft) accuses big business of rampant environmental degradation:

Big Business is primarily responsible for destroying the water we drink, the air we breathe and the food we eat. They have no care for the world they destroy, only for the money they make in the process... They basically control the legislation, and, in fact, they control the Law... They influence the media so that they can control our minds. They have made it a crime to speak out for ourselves, and if we do so we're called "conspiracy nuts" and we're laughed at... We have to force these companies to operate safely and responsibly, and with all our best interests in mind.^[27]

In 2008, author and critic Vern (no last name) published Seagalogy, a work which examines Seagal's filmography using the framework of auteur theory. The book divides Seagal's filmography into different chronological "eras" with distinct thematic elements. The book was updated in 2012 to include more recent films and Seagal's work on the reality TV show Steven Seagal: Lawman.^[28]