The Aperture Science Handheld Portal Device, often simply referred to as the Portal Gun, or its acronym, "ASHPD", is an experimental tool used to create two portals through which objects can pass.
The ASHPD has the ability to "manufacture two linked portals at once". The blue portal is fired by hitting the primary fire key, while the orange one is fired by hitting the secondary fire key. When entering a blue portal, one will always come out an orange portal and vice versa. The ASHPD is held with a hand behind the weapon, holding the handle/trigger. The other hand is placed under the cannon. A sprite in the small hole on the top of the ASHPD and a sprite in its glass tube have the color of the last shot portal. As with most of the features of the Aperture Laboratories first acquires the ASHPD in GLADOS02; it fires only blue portals. It is later upgraded in Test Chamber 11 to fire the orange portals as well (while another model is found there, it actually consists of an upgrade of the current model, as said by GLaDOS). When each of the two versions of the gun are found, they are seen placed on a pedestal in the middle of a Test Chamber. The pedestal is constantly turning on itself, and the ASHPD shoots a portal each time it faces one of the four walls of the room it is in. Chell has to use the non-player controlled gun to complete the Test Chambers and once done acquires the initial ASHPD and later its upgrade. Currently it is not known how the two single ASHPDs are combined into one to result in a "modified" single gun. Shooting an orange portal on an existing blue portal (vice versa) will create the portal right next to it, if the room available allows it. Like the Gravity Gun, the ASHPD appears to featured a zero-point energy field, allowing Chell to pick up objects. However one has to stand close to the object to do so, and it cannot be thrown, suggesting the ASHPD has a weaker field. They can be carried through a portal, a process often required during tests. Unlike the Gravity gun however, High Energy Pellets, the Aperture Science equivalent of the Combine Energy Ball, cannot be picked up, either due to their instability or a weaker energy field. The ASHPD cannot create portals on every surface. While it can on
any concrete surface, it will not work on certain tiled floors, metal, any kind of prop, doors or windows. However it works on security cameras, detaching them and making them fall on the ground. When shooting a portal on an unauthorized surface, the
weapon's ray will bounce off and be turned into blue or orange particles that shortly disappear. This constraint was added to make puzzles deeper than merely teleporting to the exit. The oval-shaped crosshair/reticle of the ASHPD indicates useful information pertaining the portals. It first starts with a completely blue crosshair, as the first acquired ASHPD can only shoot blue portals. Later, when the ASHPD is upgraded to shoot orange portals, the crosshair is cut in two parts, blue and orange. Furthermore, a smaller oval appears next to the side that has been most recently fired. Finally, when the ASHPD is held in front of a surface where portals cannot be shot, only the outlines of the two oval elements are seen. They must always be filled in to allow shooting portals. An Aperture Science Material Emancipation Grid will "reboot" any portal created by the ASHPD. In that way each Test Subject starts each new Test Chamber with a "clean" portal network, and must use their assets properly when having to come across one several times during tests. When this happens, the gun slightly shakes as the portals disappear. When Chell is killed by an Energy Pellet, the ASHPD disintegrates with her.
New Abilities in Portal 2
In Portal 2, the ASHPD seems to have new abilities, as if it was super charged much like the Gravity Gun in
Half-Life 2. This is seen in a Tech Demo demonstrating the Sixaxis controller for PC. The ASHPD's super charged abilities allow it to act much like the Physics Gun from Half-Life 2 Beta and Garry's Mod. However unlike the PhysGun, it can morph objects and stretch them out, which will be needed for certain puzzles. The ASHPD is slated to appear in Portal 2. Three models will apparently be featured; one used by Chell, the two others by two robots, Atlas and P-body. It also appears that the ASHPD will have new firing sounds, as well as new sounds when something goes through a portal. The portals are also expected to give off light in their surroundings. In the co-operative mode in Portal 2, Atlas' ASHPD will use light blue and indigo (dark blue) portals, while P-body's ASHPD will use light orange and red portals.