Portal/Chamber 16

"Due to mandatory scheduled maintenance, the appropriate chamber for this testing sequence is currently unavailable. It has been replaced with a live-fire course designed for military androids."

- GLaDOS

Turret introduction


This chamber introduces you to turrets, which will open fire if you enter their line of sight. Three turrets may try to shoot you through the glass as you enter, but luckily the glass appears to be bullet-proof. The first turret is facing away from you, and as such it can be disarmed easily. You can pick it up and toss it onto the ground, or place a portal under it and let it fall through to wherever you place the other portal. As long as it is no longer on its feet, it will shut down.

The next turret will be noticeable with a red laser beam pointing against the wall. Quickly fire a portal behind it, and pass through a new portal of your own. You could also disarm it by shooting a portal underneath it.

You may notice at some point that you have less time from when a turret sees you to when it shoots you if the turret just recently saw you as well. If you wait for the turret’s laser to stop moving around, you will have more time in its line of vision to act before it starts shooting.

An alcove containing a turret is next. Since you can't shoot a portal under it, you can instead create one on the red X painted above, and drop another turret or camera on top. Alternately, place a portal behind the turret, as with the last one, and knock it over yourself.

You may wonder at this point why there was such an obvious X hastily painted just in the right location. As you walk to the next area, you will notice two cubes behind a panel, and the word “help” drawn on the floor. Removing the cubes, notice that there is actually an additional area that you can crouch and crawl into. This is by no means a required area, but the scribblings add some important questions to the storyline. It also gives indications that all of this testing may not be as innocent as it initially seemed to be.

Two turrets are now covering the corridor. To get rid of them, you need to open a portal on the red X above each turret, and drop a weighted storage cube (or other object) onto the turrets.

Two turrets cover the next room, but you can sneak a portal behind them without too much difficulty. Then enter the side room, where you will find a malfunctioning cube dispenser, which gives you a lot of objects to toss at your next set of obstacles.

The button room contains three turrets, with a red X marked over each one. You can disarm one of them with your portals, and use the set of storage cubes to drop them on the turrets. Place a cube on the red button to open the door.

The exit is blocked by some fencing and a couple turrets, however you can still shoot portals through the fences (being sure to avoid turret fire), shut down the turrets, and proceed to the chamberlock.

Advanced
In the advanced chamber, all turrets are enclosed in metal cages from which they can shoot outwards while remaining untouchable. No picking them up, no hitting them with objects, and no portaling them somewhere else with portals beneath them.

For the first turret, you will have to portal yourself on top of the cage, crouch to get through, and quickly move around the corner. Next, place a portal on the wall behind the second turret, and walk on through. Then skip the third turret completely by simply placing a portal on the far wall.

Now is when things really get tricky. You will likely have to use cubes to prevent the line of sight between the turrets and you. If you need more obstacles than the provided cubes (you shouldn’t though), in the side room with the writing there are many brown boxes that, while you cannot pick them up, can be pushed and portaled elsewhere. While crouching behind a cube, the turret will not be able to see you, but if you pick the cube up while crouched it will, although the cube will block most of the bullets.

Place a cube on either side of you, and crouch walk until just before one of the turrets will see you. Move the cubes to a better placement, and continue. When you can, portal into the next area behind the next two turrets. Now portal into the cube room. Once there, place a portal back on a high wall where you came from, and the other portal under the various cubes, as you may need a lot of them. Head back over and get ready for the last room.

The first (relative to the entrance) turret in the room you are currently in will not be a worry, but put two cubes stacked in front of the second turret so that you don’t have to worry about it much (be careful though, as there may be a small angle where it can still shoot you). As you enter with cubes in front of you into the last room, try to get one between you and each turret as you move. You can also get the edge of a cage between you and a turret’s eye so that it will not be able to see you. Place a cube on the button so that the door opens. Place one portal on a wall just on the other side of the door, and then take the cube back off of the button so that the door closes. Now back track to safety and place the other color portal on a wall so that you have access to the other side of the door.

Before entering, be sure to know which way you will be shooting your next portal, as you will only have a brief time before you are shot. Enter and immediately portal behind the turret. Then place a portal as far down the exit hallway as you can, and come on through, moving as necessary to not be shot, and then exit.

Portals
Which turrets you take out by hand as opposed to with portals is very flexible here, but here’s a possibility: Take out the first turret by hand.
 * Bronze at 9 portals
 * 1) Blue portal behind the second turret.
 * 2) Orange portal in an accessible location. Go through behind the second turret (take it out if you wish). Run past the third turret to the two turrets facing each other.
 * 3) Blue portal on the X above the far turret.
 * 4) Orange portal on the wall or floor. Drop a cube onto the turret. Take out the near turret by simply running to it and picking it up before it shoots.
 * 5) Blue portal on a ground-level wall behind the two turrets in the next room. Go back to the existing orange portal to come up behind them and take them out manually.
 * 6) Orange portal on X above the turret facing the entrance in the button room. Drop a cube through. Take out the one facing away manually.
 * 7) Orange portal on X above the third turret in the button room. Backtrack and drop another cube through. Place a cube on the button.
 * 8) Orange portal at ground level behind turret guarding this next door. Backtrack to existing blue portal and come through.
 * 9) Blue portal somewhere in the final room. Come through and take out the final turret.

Again, flexible, but here’s a likely scenario: Take out the first turret by hand.
 * Silver at 4 portals
 * 1) Blue portal behind the second turret.
 * 2) Orange portal in an accessible location. Go through behind the second turret (take it out if you wish). Run up and grab the third turret before it shoots.  At this point you have many cubes that you can use as shields between you and turret fire. It is a little bit like proceeding in the advanced chamber, except with the advantage of being able to get rid of a turret once you reach it. Remember to crouch, and you should never need more than two cubes at a time. Take out all the turrets up to and including the ones in the button room. Place a cube on the button.
 * 3) Orange portal at ground level behind turret guarding the door. Go way back to the existing blue portal and come through.
 * 4) Blue portal somewhere in the final room. Come through and take out the final turret.

Take out the first turret by hand, but pick it back up after it’s dead. Use it as a half-shield, and toss it at the second turret when you are close enough. From here, proceed as in the silver method until you have the button pressed. Notice that you can actually see the second fence through the first fence.
 * Gold at 2 portals
 * 1) Blue portal through both the first and second fences.
 * 2) Orange portal anywhere you can get to. Go through and exit.

Steps
Picking up a turret as it’s dying helps prevent being accidentally shot. You might try using floor portals to move a cube somewhere where it will help block the line of sight between where you want to go and a turret.
 * Bronze at 70 steps
 * Silver at 55 steps
 * Gold at 40 steps

Time
Times unfortunately include the 20-second monologue at the beginning of the map.

This challenge is mostly just about getting really good at shooting portals quickly and getting rid of turrets as easily as possible. It’s really nerve-wracking because you don’t have time to get rid of all the turrets, so you end up being shot at quite a bit. Stick to it!

Here is one possible gold method. Shoot a portal on the ground at the door while you wait for the door to open. As soon as it does, shoot one at the top part of the wall so that you fall through, probably knocking over the turret in the process, and can easily continue on. Put a portal behind the next turret, and then across the next hallway. Now for the two turrets facing each other, place a portal on the X above the nearest one (this should be happening around the 30 second mark). Walk towards the two cubes and shoot a portal underneath them so that one falls through to knock out the turret, but grab the other before it falls. Then just use it as a shield as you run towards the other turret. When you are close enough, toss the cube at the turret, and quickly shoot a portal at the far corner of the next area, coming on through. Place a portal on the wall behind the turret in the button room that can probably see you right now, and another on the floor below the turret that is actually on a portalable floor. This will hopefully knock out both of these turrets. Now put a portal underneath you so you come out the other floor portal. Quickly run onto the button, shoot a portal on a wall past the first fence (past both fences if you get lucky), and come through before you die from the third button-room turret. Proceed to the exit (another portal past the second fence if necessary).
 * Bronze at 1 minute, 10 seconds (70 seconds)
 * Silver at 1 minute (60 seconds)
 * Gold at 52 seconds