Viktor Tóth

A Rat Was Trained To Play Doom II In VR, Complete With A Tiny Rig

Dan
January 14, 2022

In the nearly three decades since the release of Doom, hackers, programmers and speedrunners have done just about everything that can be done to the iconic first-person shooter.

Now, in an apparent first, a Hungarian engineer has taught a lab rat to play the game.

First, a refresher.

Let's talk about Doom for just a moment, shall we?

Released in 1993, it was one of the very first games in the first-person shooter (FPS) genre. Even now, most modern FPS games have a little bit of Doom in their DNA.

There are many ways to play Doom.

Unsplash | Clayton Robbins

Since it's a computer game from 1993, the game doesn't require many resources to play. That's probably why we've seen people play it on everything from a keyboard's tiny display to a simple graphing calculator.

How would one train a rat to play Doom?

Unsplash | Alexandr Gusev

It's a weird question, and there are logistical challenges. For instance: how do you teach a rat to use a controller?

Hungarian programmer Viktor Tóth detailed his process in a blog post. His goal was to study animal behaviors while observing their patterns.

First things first: the rat needs a VR rig.

Medium | Viktor Tóth

It isn't a rat-sized VR helmet Tóth uses, but simply a big, curved monitor. The critter is suspended over a polystyrene ball which it can run on to control the character's on-screen movement.

Lab rats need rewards, too.

Medium | Viktor Tóth

Tóth provided his research subjects with sugar water as a reward (the proverbial carrot) and puffs of air (the proverbial stick) to guide the creature along the way. Much of the action involved the rats navigating their way through the corridors of the game's labyrinthine levels.

The rats could navigate the levels.

Medium | Viktor Tóth

Three rats — Romero, Carmack, and Tom — were used in the experiment. Each could grasp the concept and move its way through the levels. One rat, Romero, was so good at navigating that Tóth even tried to teach it to shoot bad guys.

Want to do it yourself?

Medium | Viktor Tóth

Tóth notes that the whole rig, which sounds ridiculously complicated, only set him back about $2,000, which he notes is "ridiculously cheap."

That means you could either get a fancy gaming computer or a fully-featured rat VR rig. Tough choice.

Long story short: the rats can play Doom, kinda.

Medium | Viktor Tóth

"I had fun building a rodent VR rig and training rats to kinda play Doom," wrote Tóth. "Honestly, I thought it would be way easier, especially the training part, but one can't underestimate the often unyielding independence of these free spirited animals."

It's a fascinating story.

Make sure to check out the overview of the full rig below, and also read up on the detailed blog post explaining the whole scheme.

All in all, it's kind of a relief to know that we humans are still better at video games than lab rats.