One of the few "normal" characters in the Mortal Kombat franchise, Stryker is a riot control officer turned combatant, donning riot control gear and using conventional weaponry in a large-scale battle involving supernatural powers.
He first appeared in Mortal Kombat 3, played by Michael O'Brien, brandishing a nightstick, grenades, a lethal taser, and C4 explosives. In Ultimate Mortal Kombat 3 and Mortal Kombat Trilogy, he is also given a submachine gun, which helps him juggle enemies into devastating combos.
Due to his unpopularity, he disappeared from the franchise altogether (although making a cameo in Mortal Kombat: Deception) until his modern update in Mortal Kombat: Armageddon. He later received another re-imagining in the 2011 Mortal Kombat, updating his original appearance while giving him new moves and weaponry (including twin Desert Eagles to replace the submachine gun and a flashlight for blunt force trauma).
Kurtis Stryker is one of New York City's best enforcers (accomplishing many feats, including thwarting terrorists alone, earning him the title of a one-man SWAT team) and was the leader of the NYPD Riot Control Brigade (along with fellow police officer and former Black Dragon operative Kabal) in New York City while Shao Kahn's forces invaded Earthrealm. When his partner is badly injured and he finds himself to be one of the few survivors of the city, he encounters the shaman Nightwolf, who requests that he join the defenders of Earthrealm under request by its leader (Raiden, god of thunder). Still not understanding what's going on, he accepts the invitation.
Before Shao Kahn, the hideout of Raiden's chosen warriors is ambushed by the cybernetic Lin Kuei ninjas. Although they manage to defeat the cyborgs, Sindel (the undead, mind-controlled bride of Shao Kahn) appears and attacks the Earthrealm warriors.
In the original timeline, the warriors (with the help of Raiden) defeats Sindel (in which intervention from her daughter, Kitana, wipes Shao Kahn's mind control). Strengthened, the warriors defeat Shao Kahn and stop his invasion of Earthrealm.
Still not understanding the importance of his survival (compared with the supernatural powers of his comrades), Stryker mysteriously secludes himself in Earthrealm to continue his combat training, only to be called upon later in the legendary Battle of Armageddon (in which he joins the Forces of Light). Like most of the combatants in the epic battle, Stryker is killed in action (though of unknown cause).
In the series's alternate timeline (established in the 2011 Mortal Kombat), Raiden left the hideout prior to the Lin Kuei ambush (in order to plead to the elder gods). As a result, the Earthrealm warriors (including Stryker) are weakened by the attack and are massacred (with the exception of Johnny Cage and Sonya Blade) by Sindel.
After the onslaught, Raiden seeks allegiance with the lord of the Netherrealm, Quan Chi, as a final act of desperation against Shao Kahn's invasion, only to find out that Stryker's soul has become condemned to the Netherrealm (along with the souls of the other Earthrealm warriors, as they are Shao Kahn's payment for Quan Chi's allegiance).
Despite having no supernatural powers, Stryker is able to defeat Shao Kahn due to Kahn being completely unfamiliar with him (and thus having a difficult time countering him). He returns to New York City after the madness of the warlord's invasion subsides to help rebuild.
The defeat of the monstrous Blaze shows Stryker that the force of law is insufficient to defend the innocent and the weak. He decides to travel to seclusion and train himself to be the greatest warrior in all the realms, bringing justice across different worlds his own way: as a merciless vigilante.
Stryker's bravery during Shao Kahn's invasion made him a public hero, in which he receives numerous awards (including the "key to the city"), has a best-selling biography of him written, and has popular action figures of himself produced. When approached to have his story made into a featured film, he rejects it outright (as he did not want to be portrayed by Johnny Cage).