His first effort at Atari was Slot Racers for the Atari 2600.[4] While he was working on it, he had discovered and played Crowther and Woods' Colossal Cave Adventure at the Stanford Artificial Intelligence Laboratory, and decided that a graphical video game version "would be really cool".[3] However, with 128 bytes of RAM and 4096 bytes of ROM, Atari's Adventure was a much simpler program, and with only a joystick for input, the set of "commands" was necessarily brief.[3]Adventure was a hit upon its 1979 release, and it eventually sold a million copies.[2]
Atari designers at the time were not given credit for their games, because Atari feared having to bargain with well-known designers.[2] In response to this, Robinett placed a hidden object in the game that would allow the player to reach a hidden screen which displayed the words "Created by Warren Robinett," hence creating one of the earliest known Easter eggs in a video game, and the first to which the name "Easter egg" was applied.[2][3]
Robinett then wrote the BASIC Programming cartridge, finishing both BASIC Programming and Adventure in June 1979, and quit Atari.[3]
In 2016, Robinett announced The Annotated Adventure, a book describing the design and implementation of Adventure for the Atari 2600.[6] In 2018 Robinett stated that the initial book was being split into two books: The Annotated Adventure focusing on the technical aspect of the game and Making the Dragon focusing on the political story. As of December 2022 only the table of contents has been made public.
Robinett's Adventure Easter egg is a plot element in the 2011 novel and 2018 filmReady Player One.[7]