In a near future dominated by chaos, conspiracies, and biomechanical augmentations, society is divided by various organizations fighting for supremacy, and large corporations extending their power beyond those of governments. An ideological war is growing between people who accept the biotechnological progress and people who fight it. A human revolution is coming.

Adam Jensen is a thirty-four-year-old ex-SWAT member from Detroit, enrolled by a powerful biotechnology company named Sarif Industries. His job is to ensure the scientists' private security and safeguard the secrets of the company's projects. The first day after his hiring, Adam Jensen is about to attend a meeting with David Sarif, the founder and CEO of Sarif Industries, when suddenly a red alert is issued in the company laboratories. A troop of mercenaries, apparently working for Belltower Associates, breaks in and kills several scientists. After having neutralized some of the mercenaries, Adam is severely injured by one of them. He has no choice but to be enhanced with biomechanical augmentations to save his life. His goal is now to discover what were the motivations of the attackers and unravel a greater conspiracy behind their actions.

Deus Ex: Human Revolution is the third game in the Deus Ex series. The events of the game take place in the year 2027, twenty-five years before those described in the first game. Like the first installment, the game is a hybrid of a 3D shooter with a stealth angle and role-playing. All styles of play can be adopted to succeed in the missions, from a totally furtive mode (some bonuses are granted in case the player character hasn't been detected during the whole mission) to the most brutal one. The player's decisions may have an impact on the storyline.

The game offers a vast array of weapons and biomechanical augmentations (hacking, social, stealth, sight, armor, combat skill enhancements, etc.). Various amounts of experience points are awarded for completing main or secondary quests, avoiding or eliminating enemies, hacking, reading electronic books, and discovering secret passages. After having accumulated a certain quantity of experience points, the player is awarded a "praxis kit", which can be manually used to learn or improve an augmentation. These kits can also be found during exploration or purchased in clinics.

Role-playing elements include, besides augmentations and general character-building, exploration of non-hostile areas and dialogue with non-playable characters. During certain crucial moments, the player will have to participate in a "conversation battle" with a key character, selecting the correct psychological approach and influencing subsequent plot events.

A few modifications have been made to the shooting gameplay, emphasizing its tactical aspect. The third-person cover system is integrated into otherwise fully first-person gameplay. Enemies often appear in groups led by a commander; taking out the latter may demoralize enemies, making them easier targets. Though the game still contains health-restoring items, the protagonist's health regenerates itself over time.