Bethesda.net has more details on the impending closed alpha test for DOOM, id Software's upcoming return to their demonic, sci-fi shooter series. They clarify what they mean by alpha, how Wolfenstein: The New Order preorder customers can possibly participate, and how they will definitely get into an upcoming beta test. They also outline what the alpha will include and provide this video with a look at gameplay, and more on what to expect from producer Marty Stratton. Here's word on the goals of this test:

First, these are not Betas, nor are they game demos. Instead, these are a series of closed tests with limited functionality – in the case of tomorrow's Closed Alpha, one map, one mode, and a partial selection of weapons and equipment – with the goal of banging on a bunch of back-end functionality in a real-world setting. Sure, the team at id Software will be taking a close look at feedback on the gameplay itself, but that’s just part of the goal here. Much of this initial Closed Alpha is dedicated to assessing how real people connect to servers, systems and the back-end infrastructure needed to operate the game. In other words, all the technical stuff that’s essential to helping id’s vision for DOOM come to life.