It was 1979, and Atari programmer Warren Robinett was frustrated. The young engineer had already shipped a successful game called Slot Racers for the fledgling Atari 2600, and now he was working on something much more ambitious. Inspired by the text adventure games he’d played on computer mainframes, Robinett was building Adventure, a fantasy-themed graphical exploratory game and the conceptual predecessor to the action RPG.

Opposed by his supervisor, Robinett worked on Adventure in secret. After delivering a proof of concept, he developed a groundbreaking console game with multiple rooms, interactive items, and a trio of deadly dragons each instilled with its own unique AI. Proud of his work, he wanted to add his signature to the game, but was blocked by his employer’s corporate policies. Atari didn’t allow software engineers to take credit for their games, fearing that if the identities of its most talented programmers were publicly known, they might be poached away by rival companies.Robinett’s solution was to create a hidden chamber in his sprawling map. The tiny room was secreted in a maze and only accessible with a special item. Concealed within the room was a minuscule object, a single invisible pixel. By carrying that pixel into another area of the world and stacking two other items on the same screen, the player could render a certain wall passable. Stepping through the barrier led to yet another secret room. inside, the player would find the words “Created by Warren Robinett.”Robinett left Atari soon after completing Adventure, and it wasn’t until much later that his secret signature was discovered by a teenage player, who wrote Atari outlining his discovery. According to Robinett, Atari manager Steve Wright was amused by the inclusion of the hidden surprise, likening it to finding an Easter egg.Check out the video at the top of the page to see the secret in action.

Jared Petty is an Associate Editor at IGN. Adventure is his jam. Follow him on Twitter and discuss pixelated dragons.