Deus Ex prerelease builds

Before the release of Deus Ex, there were multiple prerelease builds, including alpha, beta, and other prerelease versions.

Development history

 * For additional information on the development history of the game, see also Shooter: Majestic Revelations for the immediate predecessor concept, and design document v13.12 for design concepts during later stages of development.

In 1998, the development team created the first in-game mission, which was set at the White House, although this mission was later cut during development. The first alpha build was completed in late 1998, followed by the second alpha build in April 1999. A list of documented prerelease builds leading up to the first released version is summarized below.

Unreleased Version 1.000f
An unreleased version dated Sunday, June 4th, 2000, 12:57:34 exists, with multiple changes compared to the first publicly released version, 1.002f, dated Wednesday, June 7th, 2000, 10:20:10.

Gameplay

 * The stealth pistol allows recoil weapon mods to be applied to it. This was likely changed as the stealth pistol has virtually no recoil.
 * The plasma rifle plasma has a more detailed effect while flying, this was probably reduced as it was more taxing on systems at the time.
 * Using a Fire extinguisher does not automatically extinguish the player, the player must be hit by the halon gas to be extinguished.
 * Changing level does not automatically extinguish the player, going back to the level where you were on fire makes you continue to burn, with the fire effect displaced in the location where you changed level.
 * Running out of energy mistakenly displays a debug message in the message log.
 * Placing a grenade on a wall doesn't update the amount of grenades you have on your belt.
 * Looting a body deletes the items they contain if the player doesn't have room to pick them up, losing them forever. In the final version, items are only deleted if you have a copy of the item in your inventory.
 * The game counts the player as helping at Osgood and Sons Imports in Hell's Kitchen if no terrorists are conscious and there are at least three that were knocked out by the player or killed by NPCs, killing does not count. In the final version, the player is only counted as helping if three or more terrorists were killed by the player with non-explosive weapons.
 * The UNATCO troopers outside the 'Ton Hotel are slightly broken, talking to the trooper on the right makes the left one talk.
 * In the Battery Park subway, the male hostage always talks, if he is dead it is impossible to tell the female hostage to escape.

UI

 * The music browser in the legend menu was more crude, displaying file names for each track rather than neater names.
 * Skills are sorted alphabetically, like in the E3 footage, in the final version this was changed to have weapon skills at the top.

Misc

 * Chairs in Hong Kong have a slightly different sitpoint, causing NPC legs to clip through.
 * Minor controls for volume and tremor were add to the dance music in the final version, it doesn't make a noticeable difference.
 * When asking Harley Filben who Juan Lebedev buys off, JC's inflection is different, stressing "Who does he buy off?" this was changed in the final version to be more general.
 * The 'UNATCO and the Future' datacube has the text '[Document filtered per UNATCO Terror Monitoring Act 919-05 Sec. IV]' missing.
 * Jock's infolink at the start of chapter 4 is different: "Your brother's hurt pretty bad. You'll find him at the apartment." vs the final "Your brother's hurt pretty bad. You'll find him at the apartment. If he can walk, get him to come with you. I can pick you guys up in Battery Park.". It is extremely likely that at one point you were meant to start in Battery Park, as other cut lines for UNATCO troopers exist in the final version, intended to be used at the dock and outside Castle Clinton.
 * During the escape from the Liberty Island MJ12 lab, the conversation with Paul Denton is different, with a doctor talking and mentioning that he (the doctor) has arranged for escape from the island, using your own escape as a distraction. This was likely cut because the conversation is important and required for the player to progress, which could be prevented if the doctor was too far away.
 * The Men in Black standing outside UNATCO Headquarters who tell the player about Walton Simons and his interrogations have a different voice, either a placeholder or without the MiB voice effect applied. One line is also different, with the final version being: "The prisoners on Level 3 are a sensitive matter. Leave the interrogations to Mr. Simons. You are authorized to receive your orders from Joseph Manderley, after which you will return to the helipad." while the beta has: "Mr. Simons will conduct the interrogations, that will leave you free to get your orders and return immediately to the helipad.", both versions have the same subtitles however.
 * The Man in Black at Vandenberg Air Force Base does not have their voice effect applied, sounding like normal a person.
 * The Infolinks at the Pasadena Ocean Lab don't have as much static applied to them.
 * The Men in Black at the Hong Kong VersaLife facility and the cut MiB conversation at the Area 51 hangar have quieter voices.
 * Two Woman in Black lines have no voice effect applied to them.
 * Alexander Brandon is credited for the role as Jimmy in the final version, while the beta credits Kris Nevins, who is not mentioned in the final credits at all and is likely the brother of Will Nevins who voices other characters. Kimberli Daniels also has a typo in her name.