A starship systems engineer, he is initially contracted by the Concordance Extraction Company (C.E.C) to join the crew of its maintenance ship Kellion on a search and repair mission for USG Ishimura, which is the last known whereabouts of his ex-girlfriend Nicole Brennan who had sent a brief transmission to him.

Initially a silent protagonist, Isaac is fully voiced throughout the Dead Space franchise by American actor Gunner Wright, who also provided his likeness and motion capture performance for the character.

[2] His relatability is important for the team to manage the tension with the player, and to reinforce feelings of vulnerability and the brutality of Isaac's actions when he dismembers his enemies with his mining tools in order to survive.

[2] Dead Space creator and executive producer Glen Schofield gave the character a portmanteau name inspired by the science fiction writers Isaac Asimov and Arthur C.

[7] A scene which involved Isaac being dragged through a level by a large tentacled Necromorph monster known as the Hive Mind was noted as the most challenging aspect of the game's development.

[8] The opening scene from Dead Space 2, where Isaac built an improvised weapon from a flashlight and a surgical tool to fend off an enemy, was used as the reference point for its sequel's crafting system.

[8] In retrospect, Ben Wanat, who was creative director of the series, felt that the crafting system implemented in Dead Space 3 out of their exuberance to lean into Isaac's technical background undermined the synergy that made the weapons special in its predecessors.

[12][13] Dead Space executive producer Steve Papoutsis explained that the decision was born out of the desire to enhance the game's believability as an evolution based around what the story required, and that they were careful and deliberate about when he speaks.

Papoutsis explained that while Isaac had no one to converse with for most of the first game, he has more extensive interactions with other non-player characters for its sequel, and that it would make sense for him to vocalize the horrific experiences he had endured.

[20] Isaac Clarke first appears in 2008's Dead Space, where he is introduced as a ship systems engineer assigned by C.E.C to the crew of the Kellion, led by Kendra Daniels and Zach Hammond.

Upon a rough landing by the Kellion inside the Ishimura, Isaac takes instructions from Hammond and Kendra to investigate the ship's conditions and perform any necessary repairs, but is separated from the rest of the crew when they are ambushed by Necromorphs.

After Isaac defeats the Hive Mind, he flees in Daniels' shuttle and allows the Marker to be destroyed along with the colony facility through a sabotage he had initiated earlier in the narrative.

They are attacked by a faction of Unitologists known as The Circle led by Jacob Arthur Danik, who activates explosives to destroy a local Marker confinement facility and expose its deadly signal, which causes another Necromorph outbreak to occur.

Isaac escapes the moon with Norton and his group, and they eventually trace Ellie's coordinates to a series of derelict space vessels orbiting the remote ice planet of Tau Volantis.

[1] In-game cosmetic items themed after the character appeared in some games such as Dragon Age II and the Europe-exclusive "Death Edition" of Dante's Inferno.

For Zimmerman, Isaac in particular was the "most tragic example of unrealized potential", as players know nothing about him except for hints of a history behind his relationship with Nicole, which was teased numerous times throughout the game only to culminate in a "disappointing payoff".

[33] In retrospective commentary about Dead Space, Graeme Mason from Eurogamer remarked that for many players, including reviewers like himself, Isaac being reduced to a "glorified and mute errand boy in the first game was a huge sticking point".

As it requires concentration and precision for effective use in combat, Alexandra interpreted Isaac as an individual who is misplaced but dangerous, like the Plasma Cutter, and that he manages to succeed through ingenuity and grit.

Seth Schiesel from The New York Times praised the writers and designers at Visceral for their commendable effort in humanizing Isaac and lending pathos to his narrative, so much so that he reveals himself to be a character deserving of empathy by the end of the story.

[10] Henry Gilbert from GamesRadar preferred Isaac's more substantive characterization in Dead Space 2 where he appeared to have his own thoughts and opinions, in contrast to the first game where he is constantly strung along on instructions from other characters to complete tasks.

In this context, Glbert compared Isaac to Ellen Ripley from the Alien franchise, noting the similarities in their character arcs from "scared victim to tough ‘morph killer" in the respective sequels to the originating works where they are the protagonists.

[35] Mike Wilson from Bloody Disgusting said Isaac's hallucinations of Nicole as a vehicle of his lingering guilt over her fate, which happened because he pushed her to accept a position on the Ishimura, is "perfect" for conveying psychological horror.

Mason welcomed the decision to give Isaac a voice and some agency over his own destiny, albeit as an emotionally fragile protagonist, noting the cathartic revisit to the Ishimura as a highlight of his narrative.

[39][40][41] Although Clarke ultimately did not make the cut, Game Informer staff considered his inclusion in their "30 characters that defined a decade" feature in 2010, with Ben Reeves lauding his in-universe role in battling the spread of the Necromorphs.

[46] In her paper which focuses on representations of able bodies and disability within the first Dead Space, Diane Carr analyzed at length the "colourful nature" of Isaac's numerous death scenes, as well as the fragility of his existence and the degree of protection provided by his suit in the face of the Necromorph threat.