We’re celebrating 30 years of the DOOM franchise and Quake is getting in on the festivities. A new free Add-on is now available for Quake, featuring DOOM’s iconic demons in a reality-bending crossover!

QDOOM

QDOOM reimagines the legendary first episode of DOOM (1993), Knee-Deep in the Dead, in the Quake engine. Go toe-to-toe with a deadly tag team of both Quake and DOOM foes in this double-dosed love letter to id Software’s genre-pushing franchises.

Download and play QDOOM today by visiting the in-game Add-ons menu for Quake, available on PC, Xbox One, PlayStation 4 and Nintendo Switch, with backwards compatibility on Xbox Series X|S and PlayStation 5.

• For more demon-slaying action, dive into John Romero’s free SIGIL II Add-on for DOOM (1993) & DOOM II, also available now!

Learn more about how this monster mashup came to be in our Nods to Mods interview below, starring QDOOM’s creator and Add-on newcomer, Antonio González aka Drugod:

SLAYERS CLUB: Welcome back to another Quake edition of Nods to Mods! We’re so excited to premiere an exclusive Add-on to celebrate DOOM’s 30th Anniversary celebration, available to the community for the first time. Tell us a little about yourself!

DRUGOD: Hello! I'm Antonio González from Spain, widely known as Drugod. I work as a programmer and level designer at Bloom Team, the creators of the award winning DOOM mod Bloom, which is a distinctive crossover of DOOM and Blood.

At present, we are enthusiastically developing our first video game, Voidwalker. The game is a retro FPS crafted on the Quake engine and features an aesthetic inspired by brutalist architecture. I'm confident that fans of classic shooters will enjoy it!

SC: Bringing DOOM’s seminal Knee-Deep in the Dead, demons and all, to Quake is no simple undertaking. What inspired you to create this unique Add-on?

DRUGOD: Ever since I developed an interest in modding, creating a mod for Quake has been a dream of mine; I am captivated by its aesthetic and striking use of harsh lighting. With the Bloom Team, following the release of our Bloom mod, it seemed like the perfect opportunity to revisit my aspiration of developing a Quake mod. Drawing inspiration from the successful crossover concept of Bloom, which merged DOOM and Blood, I contemplated a similar fusion between the DOOM and Quake franchises.

To bring this idea to life, I began experimenting with converting DOOM's monsters to QuakeC and the experiments yielded promising results. After successfully converting all the DOOM monsters, my next ambitious goal was to create hybrid monsters. However, the lack of 3D artists to assist in this endeavor forced me to rethink the complexity of the mod. It was during this phase of reassessment that the concept of adapting DOOM's legendary Episode 1 for Quake came to fruition. This shift in focus allowed me to pursue a simpler, yet equally engaging, modding project within the Quake universe.

SC: How did you tackle presenting players the option to select enemies from DOOM and/or Quake for this Add-on, all while still in-game?

DRUGOD: The development of QDOOM presented a unique challenge - not so much technical as conceptual, particularly in how to present options to the user. Since modifying the game menus wasn't feasible, I had to devise an alternative approach. Ultimately, I integrated the selection mechanism into the START map itself for two key reasons: First, this method aligns with the classic Quake player's experience, where one selects the episode in a similar fashion to choosing the difficulty level. Now, players can also select the type of monster in this familiar environment. Second, considering the potential of adding more episodes to QDOOM in the future, this setup allows players to change the monster type between episodes without needing to start a new game.

On the technical side, I utilized engine variables that were previously unused. These variables can store the user's selections, enabling the internal invocation of different monsters based on those choices. This approach not only preserves the integrity of saved games but also ensures compatibility, not just with [the enhanced Quake re-release] but with other source ports as well. This solution effectively balances the need to innovate within the constraints of the existing game structure, offering players a seamless yet novel experience.

SC: How long have you both been making Quake levels?

DRUGOD: My journey into Quake modding began relatively recently - around 2020, when I started exploring QC and various source ports for my initial projects. My involvement in the DOOM modding scene stretches back much further: I've been crafting DOOM maps since the mid ‘90s. However, it was in 2015 when we began to work very seriously on the Bloom mod, marking a significant shift in my approach to modding. This period marked my deeper and more dedicated involvement in the modding community.

SC: What’s your take on the modern Quake modding scene?

DRUGOD: In recent years, the Quake modding community has experienced substantial growth, a trend I attribute largely to the advent of new tools like Trenchbroom and the influential work of content creators such as Dumptruck_ds. These developments have made the engine more accessible and broadened the collective understanding of its capabilities. The [enhanced Quake re-release] has further fueled this momentum, drawing new attention to the franchise and showcasing the extensive modding possibilities inherent to Quake. This resurgence is inspiring a new generation of creators to embark on their own projects, a development I find truly exciting.

However, despite these advancements, I believe there is still a need for more resources and support. We need a greater sharing of knowledge within the community, comprehensive documentation and development of tools that are compatible with the latest operating systems to truly unleash the full potential of Quake modding.

SC: Did you work on a team to make this full episode replacement?

DRUGOD: While I'm actively involved with the Bloom Team on our Voidwalker project, I undertook this particular venture solo. My responsibilities encompassed the conversion of DOOM maps to the Quake format, specifically the BSP (Binary Space Partitioning) format, which forms the core of Quake's level structure. Additionally, I managed all the programming aspects of the project.

In terms of 2D art, my role was more limited. I made minor modifications, such as tweaking menus and adapting DOOM sprites to fit within the Quake color palette. Beyond these adjustments, I didn't delve extensively into the 2D art aspect, focusing primarily on the map conversion and programming challenges central to bringing this project to life.

SC: What tools did you use to create this Add-on? How long did it take to create?

DRUGOD: For this modding project, I utilized a suite of specialized tools: Trenchbroom for map adjustments, Slade for extracting Doom resources, GIMP for texture edits and palette corrections, Notepad++ for QC coding and map conversions, FIMG for adapting DOOM sprites to Quake's format and TEXMEX for creating Quake compatible texture files. Each tool played a pivotal role in merging elements from DOOM into the Quake engine, enabling the successful execution of the mod.

I began the development of this project in November 2022. However, the total time spent on it has been relatively brief, amounting to approximately nine months of development.

SC: Who are some of your favorite modders in the Quake community? Any mods you’d recommend to folks?

DRUGOD: I hold immense respect for the creators behind projects like Quoth, Dwell, Alkaline, Reliquary, Arcane Dimensions, Rubicon 2 and Contract Revoked. Each of these mods represents a pinnacle of creativity and technical prowess within the Quake community. They stand as true masterpieces, showcasing the incredible potential that can be achieved within the framework of modding. Their contributions have undoubtedly been a source of inspiration in my own journey as a modder.

SC: Wanna give any other shoutouts? No time like the present…

DRUGOD: I'd like to express my deepest gratitude to everyone who has supported me, particularly my family and Nahuel, whose advice and help have been invaluable. A special thanks to my colleagues at Bloom Team for their collaboration over the years and in the times ahead. I'm also grateful to the Boomers Dimension Discord Server for their support.

For those who have an interest in retro FPS games, I'm excited to share the Steam link to our upcoming project Voidwalker. If it catches your interest, adding it to your wishlist would be greatly appreciated!

In the spirit of the 1993’s most popular shareware, DOOM’s Knee-Deep in the Dead, you can now battle through an alternate enhanced Quake experience 30 years later in the free QDOOM Add-on. So whaddya waiting for? Download and play QDOOM by visiting the in-game Add-ons menu for Quake today!