Portal

This page details bugs of Portal.

To do: There's a way to fall out of the map by placing two portals on adjacent walls and shooting the corner until the view turns black. Glados slow voice glitch in ending Add link to Valve issue tracker for each bug

Final Camera Destroyed Voice Line#

In the game files, there are five voice lines intended for when cameras are knocked off walls. For most players, lines 2 through 4 will be played for the first three cameras destroyed, and line 5 played for all further ones, seemingly leaving voice line number 1 unused:

However, it is in fact possible to hear this line in-game! The game's source code (from the Source 2007 and 2018 Team Fortress 2 leaks) indicates that this line is intended to play when all 33 cameras required for the Camera Shy achievement are destroyed, but due to a programming error, this will almost never occur.

See, when a camera is knocked down, the code does three things in this order:

• It notifies the achievement system; this increments the actual counter that appears in the achievements menu and grants the achievement if applicable.
• It checks to make sure GLaDOS isn't already speaking, so that she doesn't interrupt or talk over herself.
• The code increments a separate counter on the player entity that tracks how many cameras they've knocked down, and uses that to determine which line to play.

The problem is that the code checks if GLaDOS is already speaking before incrementing the second internal counter, so if at any point a camera is knocked down while she is already talking, the counter won't increment and so will be less than 33 when the final camera is destroyed, preventing the line from playing properly. Given that a number of the cameras are located near chamber entrances or otherwise in places where GLaDOS would be speaking, a player unaware of this behavior would almost certainly happen to destroy one while she is talking and not hear the line. In order to hear it, you must wait for any existing GLaDOS lines to finish (including ones from knocking down previous cameras) before knocking down another camera; you will know if it worked correctly if one of the standard "vital testing apparatus destroyed" lines plays. If this is done, when the final camera in Test Chamber 19 is knocked down, the above voice line will play as intended.

Silent Escape 00 Voice Line#

Near the end of the map escape_00, when the player falls from on top of a vacuum tube to a lower one, GLaDOS is supposed to speak an extra voice line prior to "You should have turned left before." This line goes unheard however, as the game attempts to play the line before enabling the speaker that it would be emitted from, although the caption will still display if the player has them enabled. The line can be made to play properly by running the command ent_fire glados_microphone_speaker04 enable right before jumping down to where it plays.

Oddly, the speaker enable input is explicitly delayed 0.01 seconds after the voice line is triggered. Perhaps the mapper intended to instead delay the voice line to ensure the speaker is enabled first, but accidentally set it on the wrong output?

Still Alive Desync#

When the credits are playing, if the game is paused, the Still Alive music track continues playing while the actual credits sequence pauses. The song and the credits are now out of sync from each other and will remain that way after the game is unpaused again. This would seem to simply be a result of Source not pausing sounds when the game is paused - however, even in versions of the game where sound is paused (Xbox/PS3 since release and PC since early 2025), the credits music still isn't affected by this! This occurs because the credits code plays Still Alive using a VGUI function, meaning it is actually classified as a UI sound and thus specifically excluded from sound pausing.

Still Alive Credits Turning Into Half-Life 2 Style Credits#

When a save is reloaded during the credits sequence, the credits need to be restarted from the beginning, as they are implemented as a HUD element and save files do not store HUD state. Portal's credits were built off of Half-Life 2's credits code, but save game handling was not correctly updated and still starts the original Half-Life 2 style of credits. They are slightly bugged, appearing shifted towards the left side of the screen, but otherwise still reflect Portal's developer credits and use the right font. The player will be kicked back to the main menu at the point where Still Alive would have ended prior to reloading the save.

Normal	Post Save Load

This bug was (somewhat fittingly) fixed in Portal: Still Alive, but remains in all other versions of the game, including the latest PC build and the Nintendo Switch port. Portal 2 disallows saving during the credits, avoiding this issue; forcibly re-enabling it reveals that the bug is also fixed there, although due to the way the music is set up, it will keep its place after loading a save while the credits will reset and desync.