The game's prototype code was used as the basis for the 1979 Superman game, and a planned sequel eventually formed the basis for the Swordquest games.
The Easter egg concept pioneered by the game has transcended video games and entered popular culture.
Robinett was finishing his work on Slot Racers when he was given an opportunity to visit the Stanford Artificial Intelligence Laboratory by Julius Smith, one of several friends he was sharing a house with.
There, he was introduced to the 1977 version of the computer text game Colossal Cave Adventure, created by Will Crowther and modified by Don Woods.
The system has only one playfield and five memory-mapped registers available to represent moving objects.Only two of these registers are capable of representing more complex sprites.Robinett used those for objects and creatures within the game.While Robinett originally intended for all rooms to be bidirectionally connected, a few such connections (including one inside the White Castle) were unidirectional, which he considered to be bugs.
Such problems were explained away as "bad magic" in the game's manual.The kingdom includes two other castles (White and Black) and various obstacles and mazes within them.