Many people believe that the modern shooter was born in 2001 with the release of Halo: Combat Evolved. Those people are idiots, and Deus Ex is the reason why.
Way back in 2000, Deus Ex dropped like an angry Santa, throwing explosive presents down PC gaming's chimney with enough force to shake its foundations. Every time you upgrade your already badass character, or use a path less traveled to smoothly avoid a firefight, or talk your way out of (or into) trouble, or basically anything that doesn't involve circle-strafing demons in yet another Doom clone? That's Deus Ex smirking at you from the past.
It's not difficult to see the Deus Ex franchise as a series of self-fulfilling prophesies, with each game its own little oracular snippet of its own effect on the industry. The original Deus Ex defined the first-person shooter/role-playing hybrid in an era in which PC gaming was king. It expanded horizons and tore down barriers within the industry even as its protagonist expanded his own horizons and tore down the barriers between man and artificial godhood.
Its sequel, Deus Ex: Invisible War, was an unintended parable about the folly of economic and social conditioning toward the lowest common denominator. By tuning every aspect of plot and gameplay down in an attempt both to run on the anemic console hardware of the first Xbox era and to appeal to the typically less cerebral users of said consoles, Invisible War's creators cheated their fanbase out of the sequel they thought the franchise deserved.
It was a move that proved costly. Sales fell well short of expectations. Industry veteran and Deus Ex developer Warren Spector largely dropped off the radar after Invisible War. A planned threequel was renamed and removed from Deus Ex continuity altogether, and FPS quality in general took a nice long nosedive.
The series lay dormant until Deus Ex publisher Eidos announced Deus Ex: Human Revolution on (of all places) a French-Canadian talk show. Gamers and industry sources alike were skeptical; Deus Ex's original developers were all long gone, and most Eidos staff members old enough to have worked with the franchise had been lost in a 2007 takeover by a rival publisher.
Having seen the bridge to the future effectively burnt by Invisible War, Human Revolution instead turns to Deus Ex's past, flinging players 16 years forward to the year 2027. Mechanical augmentation, all but obsolete in previous Deus Exes, is bleeding edge technology now... um, in the future... which is the series' past... the future of which came out 11 years ago... look, just roll with it, okay?
Anyway, players hop into the role of Adam Jensen, security chief at a leading cybernetics developer. As baseline humans are so 2011, Jensen promptly has his extremities pulped by a cyborg black ops team, and his boss saves his life by given him the Six Million Dollar Man treatment. This leaves Jensen with several existential questions, like, "Is this one of those massive global conspiracies that leaves you wondering how far down the rabbit hole goes?" and "Is punching through a wall to snap a guy's neck as cool as it looks?" (Yes, and yes.)
Human Revolution is a console game that—no, wait, come back! It's okay now, I promise. Yes, that was anathema once, but that was then—modern consoles actually managed to catch up somewhat. What couldn't be done on last generation's tech is old hat this time around, so much so that the tricks pioneered by Deus Ex have been co-opted by a string of more modern shooters and adopted into "acceptable" use. Too late to save Invisible War but just in time for Human Revolution, the idiots in marketing finally realized gamers can handle console shooters that do more than shoot.
Human Revolution picks up the pieces of a decade-old franchise and reassembles them to fit in with today's games, which thankfully works now that today's games can keep up. The world, constrained as it is into next week's cyberpunk yesterday by the Deus Ex paradigm, isn't as open as a Grand Theft Auto, but the scenarios certainly are. Players are invited to augment a combination of several abilities in any way they see fit to solve problems with as much or as little finesse as they wish. When confronted with, say, a warehouse full of enemy operatives, the silent approach is just as valid as one involving judicious use of cybernetic strength and the break room's refrigerator.
So where does Human Revolution fall within the idea of Deus Ex as the self-referential prophecy? Deus Ex was about changing paradigms and the role of God, artificial or otherwise, in society; it also became a legend in its own right. Human Revolution is about evolution and the role of man in his own destiny; it wants for neither its own grandeur nor deference to its roots, having been born into an era which allows it to finally express both.