Moon base mission

During the development of Deus Ex, a moon base mission was created but was later cut from the game because it was not thematically consistent with the rest of the game. Although the mission was cut, textures believed to be used for the mission remain in the final game. Some of these textures were repurposed for other maps.

Development history
At one point during development, the final part of Deus Ex was planned to take place on a moon base. The mission would have the protagonist, JC Denton, travel to the moon to confront Ada, an AI entity who wishes to govern the world as a dictator.

This concept of confronting an AI entity in outer space appears to have been based on an even earlier endgame concept developed for Shooter: Majestic Revelations, in which JC similarly travels to a space station to confront a rogue AI entity named Adam who, like Ada, also wishes to govern humanity.

According to Warren Spector, the moon base mission originally existed together with a space station mission involving the International Space Station. After the space station mission was cut, the moon base mission was later cut as well because the developers felt that it deviated from the game's focus on "people and earthly" things. Spector made a comparison with the game Half-Life (in which the final missions were unlike the rest of the game) and suggested that the team did not wish for the final missions to feel like a completely different game.

In a 2007 interview, Harvey Smith similarly stated that the moon base mission was cut because it was not consistent with the rest of the game. Smith also noted that the concepts of the moon base were later re-realized in the final mission of the game at Area 51, which replaced the moon base mission. Steve Powers also confirmed that maps for the moon base were repurposed for the lower areas of Area 51.

Using the map editor, it can also be observed that the texture Moonscape7 in the "Moon.utx" package in the final game was repurposed as the texture of the sea bed of the Ocean Lab. Therefore, while Area 51 inherited part of the moon base, presumably the interior part, elements that were intended for the exterior design of the moon base were inherited by the map for the Ocean Lab. Other parts of the "Moon.utx" package were used for other purposes, as described below.

The moon base mission was cut prior to the beta versions of the game. Bits of the moon base's backstory remain in the game; specifically, three articles of the APR newspaper mention Chinese mining activity on the moon.

Plot
The Deus Ex Bible provides the following summary: "The objective was to stop 'Ada,' an AI that wanted to become 'benevolent' world dictator." The moon base was intended to be a lunar mining colony, and the mission was planned to involve trouble between a United Nations base and a Chinese base. Harvey Smith confirmed that the moon base was "where the game was going to end," i.e., it was intended to be the final mission of the game.

Game textures
The final game includes a package Moon.utx with textures believed to have been used for the moon base. Note that the textures of the Tube_A series form an animated sequence.

The texture Moonscape7 was repurposed as the texture of the sea bed of the Ocean Lab. The Tube_A animated texture was repurposed for the helicopter bay of the PRCS Wall Cloud.