In video gaming parlance, a conversion is the production of a game on one computer or console that was originally written for another system. Over the years, video game conversion has taken form in a number of different ways, both in their style and the method in which they were converted.
History
The earliest video game conversions were almost exclusively home versions of popular arcade games. The first known examples were conversions of Atari's Pong in the form of consoles with this one game built-in, as well as consoles that included a number of variations on the game. Atari produced their own "official" conversion of the game for home use, but a number of other imitators such as Sears' Telegames Pong IV were also on the market.
With the begin of the video game era, Atari released their 2600 console for which they licensed and produced a number of home conversions of popular arcade titles, including Pac-Man by Namco, Space Invaders and Defender. Later, other third-party developers and publishers such as Activision and Coleco became involved producing, among others, games like Donkey Kong for the Atari 2600.
Atari also sublicensed a number of their Atari 2600 conversions to be reproduced on home computers such as the Commodore 64, on which cartridge-based versions of games like Pacman and Pole Position were produced under the Atarisoft label.
In 1983, Nintendo entered the fray, producing the Nintendo Entertainment System which partly acted as a platform for bringing Nintendo's own arcade games to the home, firstly in the middle of 1983 in Japan, then later in the year in the United States. These games included Donkey Kong, Donkey Kong Jr., Clu Clu Land, Punch-Out!! and Hogan's Alley.
In 1985, Sega released the SG Mark III, which was re-released in the United States in 1986 as the Sega Master System. This also was partially a platform for bringing conversions of Sega games to the home, which resulted in home versions of (among others) Shinobi, OutRun, Space Harrier and After Burner.
The mid-1980s and the mid-1990s saw a flurry of conversions of popular arcade games to home computers such as the ZX Spectrum, Commodore 64, Amstrad CPC, Commodore Amiga and Atari ST. These games were mostly developed and published by groups who were not involved with the original developers, but who had bought the rights to create faithful reproductions of these games. Console versions of these arcade games, however, were often produced by the original developers of the arcade title, leading to a higher degree of accuracy in translation. This was most prevalent in the 1991-1992 conversions of Street Fighter II. The Super Nintendo and Mega Drive versions produced by Capcom themselves were highly acclaimed. The home computer versions were, however, less successful, with US Gold converting the game, not having access to the original source code and being forced to "imitate" the game.
The arrival of the era of 32-bit consoles such as the PlayStation and the Sega Saturn ushered in a new era of video game conversions. The Amiga and Atari ST were, at this point, at the end of their commercial lives, and the only remaining home computer that was considered a viable gaming platform was the PC, specifically with the arrival of Windows 95 and the DirectX development platform. The dominance of these platforms, the tendency for arcade developers to convert their own titles, the photographic quality of the graphics and audio that they were capable of providing, together with the decline of the traditional arcade, meant that conversions of games from the arcade were not just "pixel-perfect" (an industry term to describe accurate one-to-one conversions), but also sometimes exceeded their original source material in terms of quality, adding extra features, enhanced graphics and higher-definition sound.
As the traditional arcade game continued to decline, a greater focus on converting games between the home computer and console platforms began to take shape. Whereas games for home computers have been considered to be more sophisticated in scope, console games tend to be simpler in nature. Some home computer games such as Command & Conquer and Civilization II have been ported to the consoles in a simpler form to accommodate the target audience and technical limitations, and a number of "console-style" games have also found their way onto home computer systems. With the decline of the traditional arcade, this is a trend that is likely to continue in the field of video game conversions.
Types of conversions
Direct conversions
Direct conversions of video games can take several forms - those created by the original developers, or those sublicensed to a third party developer. Historically, conversions of titles performed by the original developer tended to be more accurate, but this was due to third parties not having access to the original source code. While licensing issues were indeed a factor, technical issues were also prevalent - most games pre-1995 were produced in assembly language, and source-based conversions could not be reproduced on systems with other processors, rendering the original source code useless. Also, while most third-party developers had access to the original graphics and audio, they could not be faithfully reproduced on older home computers such as the ZX Spectrum and developers were forced to recreate the graphics and audio from scratch.
In recent years, source-based conversions of games have become more feasible and one-to-one pixel perfect conversions are commonplace. In examples of open source games such as Neverball, BZFlag and The Battle for Wesnoth, this conversion has literally been one-to-one - the game has been precisely converted from platform to platform (usually Linux to Windows) thanks to the free availability of the source code, and differences between the versions are negligible or non-existent.
Imitations/clones
Imitations of popular arcade games were common, particularly in the early days of video gaming when copyright violations were treated less severely. While the game was fundamentally the same, the title, names, graphics and audio were usually changed to avoid legal challenges. Most imitations were of titles such as Space Invaders and Pacman. As video games became increasingly sophisticated, clones of games began to deviate from their source material in varying ways.
It has been known for a developer to create a "clone" of one of their own games. Escape (now Westone) produced a clone of Wonder Boy for the NES by the name of Adventure Island to circumnavigate a number of legal issues surrounding the Wonder Boy name and character.
Remakes
Particularly in recent years, developers have been remaking older video games with modern technology. Usually, this has been by the development firm themselves or companies sub-licensed by these developers. This was a particular phenomenon during the late 1990s with numerous 3D updates of games such as Frogger, Missile Command, Asteroids and Space Invaders. Sega have also been active in reproducing a number of their older 16-bit era titles with 3D graphics for the 5th generation of consoles (PlayStation 2, Xbox, Nintendo GameCube)
Retro/Emulation
Advances in technology and a rising interest in retrogaming have incited a trend whereby collections of "classic" games, usually arcade games, are re-released on modern gaming systems in their original forms. The original "retro pack" is widely thought to be Namco Museum Volume 1, and many similar packages have since been released by Sega, Midway, and Taito among others. This is usually carried out by means of custom emulators, which reproduce the activity of the original arcade ROMs.
Nintendo's Game Boy Advance is often considered to be a retro gaming console, which has led to hundreds of conversions of older games being reproduced for the console, including games originally written for the SNES, the hardware of which forms the basis of the Game Boy Advance.
Special cases
ZX Spectrum/Amstrad CPC
The Spectrum and CPC were exceptions during the 1980s when conversions were generally quite different from system to system. The reasons, being a tendency to write in assembly language and the considerable differences in the hardware, did not apply between the Spectrum and CPC. Although the graphics hardware differed between the two machines, they shared a common processor (the Z80) and sound chip (the AY-3-8912), which allowed relatively easy porting of Spectrum software to the CPC to save time and money. However, this practice was largely frowned upon by CPC users, who perceived it as a waste of the CPC's abilities.
Atari ST/Amiga
The 16-bit machines of the 1980s and early 1990s often found more or less identical ports between the two machines. As with the Spectrum and CPC, this was down to easy porting being made possible by an identical processor (the Motorola 68000). However, the ST's graphics and sound hardware was inferior to that of the Amiga's. Nonetheless, some conversions between these two machines (or conversions to these two machines at the same time) were very similar.
Criticism
Criticism has been made of converting video games in the past. Critics of arcade conversions often point to a lack of depth or sophistication that these games offer, especially in comparison to titles written especially for the console. Some contend that arcade conversions are produced exclusively to make money, as the design work is for the most part already carried out. This is, however, countered by the numerous extra features that modern arcade conversions often offer.
A number of criticisms have also been launched against conversions of games between home computers and consoles, particularly post-1995.
Examples
Ridge Racer
The conversion of Ridge Racer was one of the most earliest notable examples of suggested "pixel-perfect" arcade conversion. This was thought revolutionary as although pixel-perfect conversions had been produced in the past, they were usually of games that had been produced well before the console or computer itself came into being, and thus the games rarely stretched the machine's capabilities. Produced by Namco themselves as a launch title, Ridge Racer was intended to showcase the abilities of the PlayStation. However, in fact although it was an impressive conversion, Ridge Racer ran at only 30 frames-per-second, and was not displayed in the same resolution as that of the coin-op. Similar cases included the Genesis/Mega Drive conversions of Strider and Ghouls 'n' Ghosts, which were widely perceived as being 'arcade-perfect' when they were not.