Adventure

Adventure is an action-adventure game created by Warren Robinett for the Atari 2600 console, generally regarded as the first game of its genre for home consoles.⁴⁵ In it the player guides a small square avatar — Robinett called it “The Man” — on a quest to retrieve an enchanted chalice and return it to a golden castle, navigating a world of rooms, mazes, and castles while contending with three dragons and a thieving bat.⁴⁹ Programmed entirely by one person on the extremely limited hardware of the 2600, it pioneered several conventions of console gaming and is credited with containing the first widely known “Easter egg”.⁴⁹

Robinett, who was 26 when he programmed the game, joined Atari in November 1977 with a master’s degree in computer science from Berkeley, having earlier studied at Rice University.³⁷ His first cartridge was the racing game Slot Racers; while finishing it, his housemate Julius Smith took him to the Stanford Artificial Intelligence Lab, where in 1978 he played Colossal Cave Adventure, the pioneering text adventure created by Will Crowther and Don Woods.⁶¹² Robinett spent three or four hours with the mainframe game and resolved to adapt its idea — a network of rooms, objects that could be carried and used, and creatures that moved on their own — into a video game.²⁴

Inspiration and design

The adaptation posed severe technical problems. Colossal Cave Adventure ran on a mainframe with hundreds of kilobytes of memory, whereas the Atari 2600 had only 4K of ROM, 128 bytes of RAM, and a 1 MHz 6502 processor.⁴⁶ Robinett’s boss knew the disparity and told him the project was impossible; Robinett prototyped it anyway, building a feasibility version with six rooms, two objects, and one dragon in roughly a month before going on vacation, and returning to find that Atari’s marketing staff liked it.⁵¹²

Robinett’s central design insight was to translate the text game’s typed commands into joystick actions. Instead of describing each location in text, he showed one room at a time on the screen; steering the avatar off the edge of the screen served as the equivalent of “Go North” or “Go East,” which allowed the game world to span far more than a single screen.⁶¹¹ Picking up and dropping objects was handled with the joystick’s single button, and all other interactions — such as killing a dragon by touching it with the sword — were triggered by the 2600’s hardware collision detection when two graphical objects overlapped.²¹² An early version let the player carry multiple objects through an inventory screen, but Robinett discarded it both to save memory and because limiting the player to one object at a time forced a strategic choice between carrying a weapon or a treasure.⁵¹²

The finished game contained 30 rooms, 14 objects, and four creatures, three of which were color swaps of the dragon.⁵¹⁰ Robinett built subroutines that gave the dragons and bat distinctive behaviors — each was attracted to or repelled by certain objects according to a hierarchy — and these continued to run even when the creatures were offscreen, so the world behaved like a running simulation.⁴¹⁰ The offscreen action produced emergent situations Robinett had not planned, such as a player being eaten by a dragon and then carried around the world along with the dragon by the bat.⁴ Robinett’s dragons were widely likened to ducks — he acknowledged “my dragons looked like ducks” and grew fond of what he called his “Duck Dragons”.⁴¹² When a dragon killed the avatar, the player could press the console’s reset switch to reincarnate at a castle, with all objects left in place and any slain dragons revived, an early form of the “continue” mechanic.⁶

The game was conceived as a quest to retrieve the Holy Grail and return it to the castle, but Atari’s marketing department sanitized the “Holy Grail” into an “Enchanted Chalice”.¹² The bat was added late in development as a confusion factor to spice up the game.¹² Atari’s management, having seen the working prototype, pressed Robinett to turn it into a tie-in for the upcoming Superman film; Atari’s John Dunn was assigned to adapt the prototype code into a Superman game, which freed Robinett to continue his own project.⁴¹⁰ Robinett began work in spring 1978 and released the game to manufacturing in June 1979, doing all of the design, programming, graphics, sound, and testing himself, as was standard for 2600 cartridges of the era.⁷¹²

The first Easter egg

Denied any on-box credit or royalties — Atari kept its designers anonymous to prevent them from gaining bargaining power after Warner Communications acquired the company — Robinett hid his signature inside the game.¹³ He placed an invisible one-pixel gray dot, the same color as the room backgrounds, in an isolated pocket of the catacombs reachable only by using the bridge to cross the maze walls.² Carrying the dot to a spot below and to the right of a castle opened a hidden wall, admitting the player to a secret room displaying the text “Created by Warren Robinett”.²⁴ The signature graphics used about 5% of the game’s ROM, added from the memory Robinett had left over at the end.²

Robinett told no one and left Atari before the room was discovered; he later said the salary of $22,000 a year with no royalties, and the fact that a game that sold about a million units at roughly $25 each brought him nothing extra, had left him “pissed off”.³⁴ A 15-year-old in Salt Lake City was the first to find the room and write to Atari about it.¹⁴ By the time management learned of it, Robinett was gone and reproducing the mask for the ROM would have cost about $10,000, so Atari left the room in.² Steve Wright, the manager of Atari’s home videogame department, coined the term “Easter egg” for the hidden feature and made it official policy for Atari games to contain them, a practice that spread through the industry.¹²

Legacy

Adventure is credited with inventing the console adventure game and with pioneering conventions later taken for granted, chief among them a game world larger than a single screen composed of discrete linked rooms.⁴ Robinett, presenting a post-mortem of the game at the 2015 Game Developers Conference, acknowledged that it has been “widely imitated,” and named The Legend of Zelda specifically as an example of a game it influenced.⁵¹⁰ Its lineage runs directly from the text-based Colossal Cave Adventure, whose structure of interconnected rooms, portable objects, and roaming creatures Robinett translated into real-time graphical form.²⁶ At the 2015 Game Developers Conference, Robinett said he was then finishing an e-book titled The Annotated Adventure, which was to include the game’s complete engine; for that purpose he translated the original assembly code by hand into C to make it more readable.⁵¹⁰