Perpetual Testing Initiative

The Perpetual Testing Initiative is a level editing and sharing service for Portal 2, released by Valve on 8th of May 2012. It is free for all who purchased Portal 2, and is included directly in the game. Users can create levels, play them, and also share them online for other players to play. The level editor features a simple interface, and the ability to test play the level.

Storyline/Plot
The Perpetual Testing Initiative was a project administrated by Cave Johnson as Aperture Science was becoming bankrupt. Johnson promoted that the Multiverse Theory exists and that there are infinite universes with infinite Aperture Science facilities. The layout of the project is to trick the more financially-stable versions of Aperture, by planting blueprints of testchambers on the desks of unaware associates of alternate universes and stealing the chambers while they are constructed. Johnson admits that the project was indeed a con plan, and that they are robbing the more-stable versions of themselves to produce more testchambers.

Affecting Gamplay
The Perpetual Testing Initiative has a story-based plot, and is the second DLC of Portal 2. Players are allowed to use a new in-game map editor that is shown as a blueprint of a testchamber. The testchamber is then compiled through the Source engine and then rendered as an actual map. The test subjects you play as in the game have the look of the simple human figure, seen in trailers for the Portal games. Players can then upload their creations by using the Steam Workshop, where other players can download and play testchambers freely. This map editor is only available to both PC and Mac versions of Portal 2.

Trailer
Trailer released by VALVe introducing the initiative for the DLC