3D Realms Entertainment ApS

In 1994, Apogee Software, Ltd. created a new division, 3D Realms Entertainment, with the goal of developing 3D action games.

3D Realms' first title, Terminal Velocity (1995), developed by Dallas-area developer Terminal Reality, was an arcade-style, fast-paced fully 3D futuristic flight combat game. This was the first shareware game to get on the cover of a major gaming magazine (the now-defunct Computer Game Player). Next came Duke Nukem 3D (1996), the first 3D installment in the series.

Financially, 3D Realms was able to self-fund internal development of entire projects. In fact, 3D Realms has never had a game budget or used a spreadsheet for budget planning - they only had expense tracking.

Originally, Action Entertainment's 3D games were going to be published under the Apogee name. However, in late August of 1994, 3D Realms was born, and the four next-generation 3D games that Action had under production - Duke Nukem 3D, Shadow Warrior, Blood (eventually published by GT Interactive) and Ruins: Return of the Gods (later cancelled), all of which used the Build engine - moved under the 3D Realms label.

After their successes in the 1990s, the company would produce titles developed by other companies, most notably the first two Max Payne titles and Prey (2006). Meanwhile, they were developing Duke Nukem Forever in-house, the process of which became infamously long and troubled.

On 6 May 2009, amid financial difficulties, the company laid off its development team. In September 2010, Gearbox Software picked up the development of Duke Nukem Forever and published it on 9 June 2011, with the development cycle totaling at an unprecedented 15 years. The Duke Nukem IP would also eventually be sold to Gearbox Software.

On 3 March 2014, the company was acquired by the Danish investment firm SDN Invest, and became the publishing-oriented sister company to Interceptor Entertainment (today Slipgate Ironworks) and moved to Aalborg, Denmark. The CEO position was taken by Frederik Schreiber, while Scott Miller was initially an advisor before fully moving to the relaunched Apogee Entertainment by 2021.

While 3D Realms has since focused on internally developed games, it would (co-)publish third-party AA and indie projects, such as Cultic and Ripout. Since the success of Ion Fury, the company started the annual event Realms Deep, where it would not only showcase in-development projects, but focus on spotlighting independent productions by smaller teams and the community of the so-called "boomer shooter" games.

On 5 August 2021, the company was acquired by Saber Interactive, which was then a subsidiary of the Embracer Group. When Saber Interactive split from Embracer on 14 March 2024, 3D Realms and Slipgate Ironworks were part of Saber's portfolio that moved alongside them.