Early history of video games
Throughout the rest of the 1960s, digital computer games were created by increasingly numerous programmers and sometimes sold commercially in catalogs. As the audience for video games expanded to more than a few dozen research institutions with the falling cost of computers, and programming languages that would run on multiple types of computers were created, a wider variety of games began to be developed. Video games transitioned into a new era in the early 1970s with the launch of the commercial video game industry in 1971 with the display of the coin-operated arcade game "Galaxy Game" and the release of the first arcade video game "Computer Space", and then in 1972 with the release of the immensely successful arcade game "Pong" and the first home video game console, the Magnavox Odyssey, which launched the first generation of video game consoles.
Video game graphics
Some of the earliest video games were text games or text-based games that used text characters instead of bitmapped or vector graphics. Examples include MUDs ("Multi-User Dungeons"), where players could read or view depictions of rooms, objects, other players, and actions performed in the virtual world; and roguelikes, a subgenre of role-playing video games featuring many monsters, items, and environmental effects, as well as an emphasis on randomization, replayability and permanent death. Some of the earliest text games were developed for computer systems which had no video display at all.