A hacker has somehow managed to get the classic FPS game Doom to run inside another game of Doom.
![](https://static.wixstatic.com/media/ee0695_66d36907598042deb71b68781b3a5270~mv2.png/v1/fill/w_49,h_28,al_c,q_85,usm_0.66_1.00_0.01,blur_2,enc_auto/ee0695_66d36907598042deb71b68781b3a5270~mv2.png)
Youtuber and Doomworld community member kgsws posted a video on Youtube showing the technical achievement in action.
This is only possible on the original DOS copy of Doom 2 due to an exploit that enables code execution inside the game.
He also got the game Heretic running inside Doom.