Hideo Kojima originally planned the third Metal Gear game, to be called Metal Gear 3, and to release it for the 3DO Interactive Multiplayer in 1994. Conceptual artwork, by illustrator Yoji Shinkawa, of the characters Solid Snake, Meryl Silverburgh, who was also a character in the adventure game Policenauts, and the FOXHOUND team, were included in the Policenauts: Pilot Disk preceding the release of the full 3DO game in 1995. However due to the decline of the 3DO hardware, development of the game shifted to the PlayStation shortly after it was released.
Kojima retitled the game Metal Gear Solid, choosing this over the working title Metal Gear 3. This was due to the fact that he believed that the first two MSX2 games in the series were not very well known. He used the word 'Solid' which was chosen due to the game being the third installment in the series, and because it uses 3D computer graphics. Sequels to this game also use the Metal Gear Solid title, and follow a new numeral progression.
The development for Metal Gear Solid began in mid-1995 with the intention of creating the "best PlayStation game ever". Developers aimed for accuracy and realism while making the game enjoyable and tense. In the early stages of development, a SWAT team educated the creators with a demonstration of vehicles, weapons and explosives. Hideo Kojima, the director, stated that "if the player isn't tricked into believing that the world is real, then there's no point in making the game". To fulfill this, adjustments were made to every detail, such as individually designed desks.
Hideo Kojima created the characters of Metal Gear Solid. Modifications and mechanics were made by conceptual artist Yoji Shinkawa. The characters were completed by polygonal artists using pencil drawings and clay models by Shinkawa. Kojima wanted greater interaction with objects and the environment, such as allowing the player to hide bodies in a storage compartment. Additionally, he wanted "a full orchestra right next to the player"; a system which made modifications such as tempo and texture to the currently playing track, instead of switching to another pre-recorded track. Although these features could not be achieved, they were implemented in Metal Gear Solid 2: Sons of Liberty.
Metal Gear Solid was revealed to the public at the E3 gaming event in 1997 as a short video. It was later playable for the first time at the Tokyo Game Show in 1998 and officially released the same year in Japan with an extensive promotional campaign. Television and magazine advertisements, in-store samples, and demo give-aways contributed to a total of US$8 million in promotional costs. An estimated 12 million demos for the game were distributed during 1998.
