Doom Captcha Alternative

Guillermo Rauch shares how he created a viral Doom-based captcha alternative.

"I hate captcha first of all - where you go to a website and it tells you 'please tell me how many stop lights or select the staircases.' So I created one which was instead of selecting staircases or stop lights, you have to kill three enemies in Doom.

The idea came over Christmas break. I went to V Zero and said I want to create a captcha that looks exactly like Google captcha because it needs to look familiar for people for the joke to land. I took advantage of the fact that Doom has been open sourced. I took a webassembly version of Doom that can run inside the browser and prompted my way to spawn the user in a very specific level. This actually involved hacking the C codebase of the game and setting it up so it was a constrained version of the video game - you kill three players and you pass the captcha.

It's almost like creative engineering. I started with V Zero, created this thing, and it went viral with three or four news articles written about it. But it literally took a couple hours of prompting. I've been an engineer for a couple decades now, and I no longer write code - I only prompt."