3D Realms is best-known for Duke Nukem's successful run of games in the '90s, including Duke Nukem 3D, one of the landmark games in the FPS genre. In recent years, however, it's rebranded to focus almost exclusively on retro-style FPS games, such as Dusk, Amid Evil, and Ion Fury (previously Ion Maiden).
Now, 3D Realms has announced an online event that will highlight upcoming games in that space, such as Wrath: Aeon of Ruin, New Blood Interactive's Gloomwood, and Nightdive Studios' System Shock remaster. Other studios will share new game announcements as part of the event, including several that aren't listed here. Realms Deep will run from 11 AM PT / 2 PM ET to 4 PM PT / 7 PM ET on September 5 and 6, and a sale on 3D Realms games on Steam will accompany it from September 3 to 7.
According to a press release, both 3D Realms and 1C Entertainment will reveal new games at the event, including a dark-fantasy FPS that is likely in the vein of Heretic, Hexen, and the recent Amid Evil. The event will include several special guests, including John Romero (Doom, Quake), American McGee (American McGee's Alice), and Jon St. John (the voice of Duke Nukem). It will also serve as a charity drive, with all proceeds from exclusive event merchandise going to Child's Play.