GAME · 2007
Portal
- Platforms
- Microsoft Windows, macOS, PlayStation 3
32 archived facts 6 topics 1 source Last reviewed Sep 2026
All facts (32)
- #001
Portal originated from Narbacular Drop, a 2005 freeware game created by students at the DigiPen Institute of Technology.
- #002
Robin Walker, a developer at Valve, encountered Narbacular Drop at DigiPen's career fair and, impressed, reached out to the team with advice and an offer to present the game at Valve's offices.
- #003
After the team's presentation, Valve president Gabe Newell offered them jobs at Valve so they could develop the concept further.
- #004
Gabe Newell said he was impressed with the team because they had carried the concept through, having already built the interaction between portals and physics and completed most of the work Valve would otherwise have had to do.
- #005
Portal was built as a prototype in an in-house 2D game engine used at DigiPen so the team could test how well the portal mechanic worked.
- #006
Portal kept the orange-and-blue color scheme from Narbacular Drop for telling its two unique portal endpoints apart, but its portal gun cannot create a portal through an existing portal, which Narbacular Drop allowed.
- #007
Portal abandoned the original princess-escaping-a-dungeon setting in favor of the Aperture Science approach.
- #008
Portal took roughly two years and four months to finish once the DigiPen team joined Valve, with no more than ten people working on its development.
- #009
During Portal's first year of development, the team concentrated mainly on gameplay and had no narrative structure; playtesters who found the game fun asked where the test chambers were leading, which prompted the team to create a narrative for Portal.
- #010
Portal's team worked with Marc Laidlaw, writer of Valve's Half-Life series, to place Portal within the Half-Life universe, partly because the project had limited art resources and reused Half-Life 2 assets instead of creating its own.
- #011
Marc Laidlaw opposed Portal's crossover with the Half-Life universe, saying it "made both universes smaller" and that he had to react as gracefully as he could to the fact that it was going there without him.
- #012
Marc Laidlaw said the crossover made no sense except from a resource-restricted point of view.
- #013
Valve hired Erik Wolpaw and Chet Faliszek to write Portal.
- #014
The idea of a computer AI guiding the player through experimental facilities to test the portal gun emerged early in Portal's writing process.
- #015
Early drafts for Portal featured a "polite" AI in humorous situations, an approach the writers found well-suited to the game and which led to the creation of GLaDOS.
- #016
According to Erik Wolpaw, Portal was designed with a clear beginning, middle and end, with GLaDOS undergoing a personality shift at each of those points.
- #017
According to Wolpaw, the choice of cake as Portal's reward grew out of the development team's early attempt to base the game on a philosopher or school of philosophy; after roughly 15 minutes of silence, someone noted that many people like cake.
- #018
Kim Swift wrote and drew the cake element of Portal as well as the additional messages shown to the player in behind-the-scenes areas.
- #019
Portal's austere settings resulted from playtesters spending too much time trying to solve puzzles with decorative but non-functional elements, so the setting was minimized to make usable puzzle aspects easier to spot. The clinical feel of the film The Island was used as a reference.
- #020
Portal's team planned a third area, an office space, to follow the test chambers and maintenance areas, but ran out of time to include it. They also dropped the introduction of the Rat Man, the character who left messages in the maintenance areas, to avoid creating too much narrative; the character was later developed in the tie-in comic "Lab Rat".
- #021
According to project lead Kim Swift, Portal's final battle with GLaDOS went through many iterations, including James Bond-inspired lasers that the player would be chased by, a concept nicknamed "Portal Kombat" in which the player redirected rockets while avoiding turret fire, and a chase sequence following a fleeing GLaDOS.
- #022
Portal's team settled on a simple puzzle with a countdown timer near the end of the final battle, with Kim Swift noting that time pressure makes people think something is more complicated than it really is. Wolpaw admitted the neurotoxin gas was cheap to make, which simplified the dialogue during the battle.
- #023
Chell's face and body in Portal were modeled after Alésia Glidewell, an American freelance actress and voice-over artist whom Valve selected from a local modeling agency for her face and body structure.
- #024
According to Wolpaw, while the turret voice was still being sought, Ellen McLain performed a sultry version that did not suit the turrets but was liked enough that a slightly modified take became the model for GLaDOS's final incarnation.
- #025
Kim Swift said that Portal's long level Box Marathon was designed so players would carry a box from start to finish, but because players kept forgetting it, the team added dialogue and a heart to the cube and kept escalating until players grew attached to it.
- #026
Kim Swift stated that any similarities between Portal's Weighted Companion Cube and psychological situations in the Milgram experiment or 2001: A Space Odyssey are entirely coincidental.
- #027
The full name of Portal's portal gun, Aperture Science Handheld Portal Device, abbreviates to ASHPD, which resembles a shortening of Adrian Shephard, the protagonist of Half-Life: Opposing Force. Fans spotted the similarity before Portal was released, so the team added a red herring by highlighting the letters of Adrian Shephard on keyboards found in the game.
- #028
The Regent Bakery has said that its Black Forest cake has been one of its more popular items since Portal was released.
- #029
Portal's soundtrack consists mostly of non-lyrical ambient music by Kelly Bailey and Mike Morasky, described as somewhat dark and mysterious to match the environments' mood.
- #030
Jonathan Coulton wrote Portal's closing credits song "Still Alive", which Ellen McLain, a classically trained operatic soprano, performed as the character GLaDOS.
- #031
According to Wolpaw, Coulton was invited to Valve a year before Portal's release, and after meeting him with Kim Swift it became clear he had the right sensibility to write a song for GLaDOS.
- #032
Portal's soundtrack appeared as part of The Orange Box Original Soundtrack, and music from both Portal and its sequel was included in the four-disc retail bundle Portal 2: Songs To Test By (Collector's Edition) released on October 30, 2012.
Sources & editorial notes
Sources for the entries on this page
- Wikipedia Portal (video game) — Wikipedia
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