Complete Portal Walkthrough


Portal basics

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Portal is a PC/X360 game where you play a silent female protagonist in a large test facility, owned by Aperture Science. Aperture Science is a corporation in the HalfLife Universe, and prior to HalfLife 2, a major competitor for funding (provided by the DoD of course) against Black Mesa.

“Why write this tutorial?”
Why not? Well, this morning, nobody had written one. By the time I typed it all out, there were three posted. If someone has a problem with the others, maybe I’ll state it in a different fashion, and help some people out. Plus, I have some neat information on! Plus, I have camera information!

“A game about a Portal-Gun? Didn’t they have portals in Prey?”
Yes, they did, but they also had portals in “Narbacular Drop”, which was made by DigiPen (Before Prey had ever come out, if I recall correctly). The entire team that made Narbacular Drop was hired by Valve. Right out of school. That’s what you get for thinking with portals!

“I heard this game was short. Is it worth it?”
Absolutely. You won’t want to go back to other styles of games. It’s addictive!

“Are there only nineteen levels? That doesn’t sound like a lot.”
There are actually twenty “Test Courses”. They start their arrays at Zero. Of course, the early puzzles are very simple, and you don’t even start with a portal gun!

“I don’t?”
Nope. You start with your wits, and the ability to pick up objects.

“Didn’t I see some weird website about Aperture Science a while back?”
Probably. And yes, it’s related to Portal. Just point your browser to; or

“How many Achievements are there?”
In both the XBox360 and the PC version, there are achievements. I can’t speak for the XBox users, since I own the PC version, but maybe they’ll help me out. The achievements section lists them all.

“How can you play an entire First Person SHOOTER without a weapon?”
Well, it wasn’t easy, but when it comes down to it, Portal is really a Puzzle Game at heart. Even when there are things shooting at you, you could theoretically get through the whole game without taking any damage.

“You take damage? Whoa. How much life do you have?”
As long as you don’t get hit by too many bullets, you stay alive. Then again, there are some things that will destroy your character instantly. Watch out!

“Can I ask a question too?”
Feel free to ask me anything. If I consider it worthy, and I know the answer, I’ll add it here.

[Game Mode Tutorials]
There are five different modes to play the game.

The first mode you will encounter is the Storyline Mode. You must play this mode to unlock the other modes. (You have to get to level 13 in the main game before you can play level 13 in the other modes.)

The next easiest mode is the “Advanced Mode”. You can play any Bonus Room level you have unlocked so far in “Advanced Mode”. The levels have been changed in this mode, and they are much more challenging.

The three hardest modes are all found in “Challenge Courses”. Some of these will seem downright impossible. To get Gold on some courses, you need to fire ONLY TWO portals, or beat the level in ONLY TEN seconds! Yes. Difficult indeed. But with a bit of thinking, and maybe some ideas I’ll write in this guide, you can figure them out on your own! ;)

[Tips for Beginners]
For the most part, this game is fairly linear. There will be places that you can’t get to. This usually involves solving a puzzle. Sometimes it’s easier to shoot a portal through a door. Sometimes you have to do it the hard way. The best I can tell you is to keep at it. Really, you shouldn’t have to read this guide for every level. The game is fairly straightforward. The only level I had any problem with was level 18 (They didn’t fully explain the concept you need to use in the last room of this level, so I was stuck). But now, I am thinking with portals!

Something else to note is that you can’t place a portal on moving concrete. When concrete starts to move, any portal that was on it will disappear. Keep this in mind, as some of the Advanced Rooms exploit this fact.

[“Weapons Guide” – Using Portals for Fun and Profit!]
You only get one weapon in the game. The “Portal Gun”. There are two versions of this gun, however.

When you start the game with no portal gun, GLaDOS places all the portals you will need. When you get the “Downgraded portal gun”, GLaDOS places all of the orange portals you will need. The “Downgraded gun” only shoots blue portals. Once you acquire the “Upgraded gun”, you can place both portals, and none will be placed for you.

There are a variety of weapons that will be used against you. I will list them here, and they are also listed on every ‘billboard’ before you enter the level.

  • Aperture Science Weighted Cubes. These can fall on you and cause damage. This is shown on every ‘billboard’ before each level that has cubes. Though I have never found a way to kill myself with spare cubes, it doesn’t mean that it can’t be done. Maybe if I caused a cube avalanche…
  • Energy Pellets. These balls of energy are usually fired out of Energy Emitters, and usually, the goal is to deflect or redirect the balls of energy into Energy Receptors. Energy Receptors are usually wired to Platforms or Doors that will help you. These Energy Pellets can also be used for knocking over turrets.
  • Pools of Acid. Do not fall into these. Normally, this feat is easy, but there are some rare exceptions.
  • “Friendly” Turrets. These have a “Friendly” red laser indicating their line of sight. Their visual range is about 45 degrees to either side, however. If you find yourself being shot by a turret, duck and cover! Alternatively, you could portal yourself away (Aim down, fire portal), but I find that takes too much thought. If I came from somewhere safe, I make sure I can get back to it. If you can’t get back to it, bring a weighted cube or two with you, at least, for cover. The only way to stop a “Friendly Turret” is to knock it over, before it shoots you with too many “Friendly Bullets”.
  • Cake? Well, it’s listed on the billboard, but cake has never hurt me. ^_^
  • Other? There are rumours that there are other types of weapons to be found in the Aperture Science Testing Facility that can hurt you! Are these rumours actually true, or just fabricated? Are there weapons that can shatter glass? Can you use them to your advantage somehow? Can they be fired through portals? Hmm!

How do you use portals “for fun and profit”, you ask?
Well, I think it goes something like…

  1. Fire blue portal.
  2. Fire orange portal.
  3. ???
  4. Profit!


[A Note on Techniques from an advanced player]
There are a few techniques listed here that are demonstrated in the early maps. There are a few techniques here that are required to beat the game. There are a few techniques here that only the advanced players know about. Hopefully these will help you, before you get to the actual walkthrough and spoil it for yourself.

Flinging: This concept is taught on the latter half of the course. It involves placing one portal on a high-up wall, and shooting the ground with another portal, just before you hit it. When you do, you will “fling” out of the higher portal with high velocity, flying over any walls or gaps that might be in your way. This technique comes in handy extensively in the bonus rooms.

Firing in Midair: There are two ways to do this. The flinging technique described above uses this to your advantage.