Doom runs in Microsoft Paint via clipboard trick

Doom now runs inside Microsoft Paint thanks to a new project created by Microsoft Azure CTO Mark Russinovich. The application, called DoomPaint, does not actually execute the classic first-person shooter inside the drawing tool. Instead, the engine renders the game in the background and pushes frames to the Windows clipboard. Paint then pastes these images onto its canvas, creating the illusion that the game is playing directly inside the software.

Russinovich used a tool called ViZDoom, which is built on the open-source ZDoom engine. This platform usually runs headless for artificial intelligence research, but in this case, it handles the actual game logic and rendering. The setup loads the original shareware version of the game, using BSD-licensed Freedoom maps for levels not included in the original release. A low-level keyboard hook captures player inputs like movement, shooting, and strafing, ensuring the keystrokes go to the game and not to the Paint application.

The process requires more than simply hammering the Ctrl+V key repeatedly. If the clipboard updates too fast, Paint cannot read the new data before it is overwritten, causing the display to glitch or freeze. Russinovich solved this by publishing a single OLE data object that Paint reads. When the drawing app finishes processing a frame, it signals the engine to prepare the next one, which prevents a data race condition and keeps the game moving.

Performance varies depending on the hardware and the resolution setting. The engine runs on its own thread at the game’s native tic rate of 35Hz, but the final frame rate is capped at 35 fps. This is because the computer must process and composite the pasted image before the next frame arrives. On weaker machines, the speed can drop significantly, sometimes reaching what Russinovich jokingly describes as “spreadsheet-tier” performance.

How to play the game inside the app

Because every frame is a legitimate document edit inside Paint, the project has some unique features. Players can use the undo function, Ctrl+Z, to step backward through the game history frame by frame. Choosing File > Save produces a genuine PNG screenshot of the current moment. The project also includes the original Episode One music, converted from the game’s MUS format to MIDI on the fly, along with the standard sound effects.

“Paint renders the game but does not compute it. Paint computes nothing. Paint has never computed anything. That’s the joke,” Russinovich explains. The software is available on GitHub under an MIT license. Running the batch file sets up a Python virtual environment and installs the necessary dependencies. ViZDoom boots directly into a map, so there are no title screens, demos, or in-game menus to handle.

It is not the first time Doom has been ported to an unusual interface. The game has previously run on everything from satellite hardware to wallets made of living human neurons. In the past, the late John McAfee even demonstrated the game running on a device he claimed was “unhackable.” The DoomPaint project shows that the game’s engine remains capable of adapting to nearly any graphical environment, even if the result is occasionally sluggish.