While Portal 2's single player offered a hardy challenge, the real mind benders are found in the co-op campaign. The possibilities are much bigger with four portals, and it can be frustrating when two brains can't crack the puzzle. While we don't recommend using the guide for the whole thing, working your noggin is kind of the whole point, getting frustrated at a particular puzzle happens to the best of us.
Thankfully we've noodled out all the solutions for you so you can check out our video walkthroughs if you encounter a particularly difficult challenge. Because the co-op is a little lighter on plot than the campaign, you can rest assured that this guide will be spoiler free.
For the first chamber of the game, all that needs to be done is to have one player leave a portal in the beginning room while the other opens the doors using the floor buttons. When they enter the final room, they simply need to drop another portal that will allow the other player to reach the exit.
It is pretty much the same tactic in chamber 2 as it was for the first one, except for the second part of the test. For the second part, both players simply need to hit the buttons at the same time, which will allow the ball to drop and lead to the exit.
For the first part of this chamber, both players need to set up two portals to allow the lens cube to direct the laser through to exit opening. The second part is a bit trickier as you first need have one player lower the wall and the other use the laser to take out the turrets. When they are clear, use the 4 portals- 2 in front, one behind and one on the right side wall- to direct the laser to the receptacle to lower the stairs.
For this chamber, one player will need to leave a portal at the entrance room and then enter the glass enclosure. The other then will need to use the buttons on the floor to lift and lower the blocks inside without crushing the other player. When the player inside the enclosure grabs the lens cube, they can then drop their other portal to exit. Once out, place the lens cube under the laser and direct it at the wall in front. Place a portal on that wall and one up behind and you will be able to move on to the next chamber.
This chamber requires one player to direct the laser at three switches to allow the other player to progress through. First hit the left side switch to raise the spikes while the other player places portals above the two platforms on the center wall. When at the first portal, the other player then needs to raise the second platform while the other player sits in between portals. Once the platform is high enough, hop onto it and then the other player will need to use the laser on the right side switch to raise the next set of spikes. Once through, the player directing the laser will need to set it at the left switch and then head for the portal above the first platform. The other player can then change the second portal to the exit area so both players can leave.
For this first “outside the testing area” chamber, a player will need to fire a portal down at the doorway and another on the wall on the walkway. Once inside the room, both players will need to pull the switches at the same time to open the door. Once the door is open, a portal will need to be fired through the open door. Once that portal is up, fire another on the wall beside you and grab the disc off the table. Bring it back through the portal and back to the office room where the big sign says to insert.