Deus Ex

Deus Ex is a series of action role-playing video games, originally developed by Ion Storm (2000-2003) and later Eidos-Montréal (2011-2017). The series began with the titular first game published by Eidos Interactive in 2000, and continued in three further mainline entries, and multiple spin-off titles. The gameplay combines first-person shooter, stealth, and role-playing elements, and has levels which offer multiple solutions to problems. A recurring feature is augmentations, mechanical or nanotechnological artificial organs which the protagonists use in their quests and impact gameplay styles. Set in a science fiction cyberpunk future, the series follows characters investigating mysteries tied to conspiracy theories and organizations including the Illuminati. Recurring themes across the series include transhumanism, terrorism, and discrimination.

The original game was created by Warren Spector, who wrote the original design document and created the initial setting inspired by multiple pieces of science fiction and political fiction. Ion Storm developed a sequel, Invisible War (2003), and attempted to make a third entry before closing down in 2005. The series was restarted by Eidos-Montréal in 2007, with the prequel Human Revolution (2011). The success of Human Revolution prompted a series revival, with a 2016 sequel and multiple spin-offs under then-publisher Square Enix.

The series as a whole has been praised for its gameplay design and setting, with some journalists citing the original Deus Ex as a prominent example of the "immersive sim", a category also attached to other series entries. Individual games have seen varying contemporary and retrospective reception. Beginning with Human Revolution, the series has seen multimedia expansions into comics and novels, many released as part of a project dubbed the "Deus Ex Universe".