The entire Deus Ex series is 75 percent off on Steam through June 25, as individual titles or as a package deal. Deus Ex: Human Revolution (Augmented Edition) is $7.50, and the original Deus Ex Game of the Year edition and Invisible War each run $2.50.
Grab all of these, plus The Missing Link DLC, Tactical Enhancement Pack and Explosive Mission Pack DLCs for Human Revolution for $15 in the collection sale.
You play Adam Jensen, a security specialist, handpicked to oversee the defense of one of America's most experimental biotechnology firms. But when a black ops team uses a plan you designed to break in and kill the scientists you were hired to protect, everything you thought you knew about your job changes. At a time when scientific advancements are routinely turning athletes, soldiers and spies into super-enhanced beings, someone is working very hard to ensure mankind's evolution follows a particular path, and you need to discover why the decisions you take and the choices you make, will be the only things that can change it.