According to Nvidia, a free Steam copy of Middle Earth: Shadow of War is a part of the "Forge Your Army" bundle and will be bundled with Geforce GTX 1080 Ti and GTX 1080 graphics cards, as well as notebooks and systems based on these graphics cards, and will last until October 16th.
In case you missed it, Middle Earth: Shadow of War is an action role-playing video game developed by Monolith Productions and published by Warner Bros Interactive Entertainment and an upcoming sequel to 2014's Middle Earth: Shadow of Mordor game. It will launch on October 10th on the PC, the Playstation 4 and the Xbox One.
Bear in mind that the bundle is only available from eligible retailers/e-tailers, partners, and system integrators so if you are looking to buy any of those graphics cards and/or systems, you should check out the official bundle page. Some Nvidia AIB partners have already announced that they are a part of the same bundle deal, including EVGA, and others should follow soon as well.