For those longing for more Portal puzzles, Portal Reloaded is sure to whet the appetite of any fan of the series. This fan-made mod for Portal 2 brings back many of the game’s familiar mechanics and introduces a groundbreaking new one, the time portal.
One of the more confusing puzzles in the game is chamber 20. Players must take advantage of their ability to pass through time to raise and lower two platforms that elevate them toward the exit. Here are the steps needed to overcome chamber 20.
Solving Chamber 20 in Portal Reloaded
Upon first entering the chamber, the test subject will notice two platforms that lead to the exit. One is lowered by placing weight on the large ground button, while the other is kept up by a reticle that's powered by a laser near the ceiling. The goal of this chamber is to lower both platforms so the player can use them to elevate themselves to the exit.
On the right of the chamber, there’s a button across the water. It’s unreachable unless a light bridge is there to serve as a platform. Pressing it will cause a testing cube to fall from the roof, but it will fall onto an aerial faith plate that launches it right into an emancipation grill, vaporizing it instantly. There’s a spot on the ceiling in front of the cube’s trajectory where a portal can be placed, and sending a light bridge there will create a barrier that saves the cube from being fried. This means that two light bridges are needed, one for the player to walk on to reach the button, and one to save the cube. Thanks to time travel, this is possible, as there is a light bridge present in the present and the future.
It’s necessary for this cube to be grabbed in the present so its future version can be brought back, so begin by creating the cube-saving barrier in the present. Make sure the portal on the ceiling is as close to the button’s left side as possible so the cube will bounce off it and land on the light bridge. If it’s too far, the cube will bounce in the water. Then, create a time portal anywhere and go to the future. This is where the player will create their platform, so fire the portal gun at the wall next to the button and make a time portal at the very end perpendicular to where the light bridge is. Go back to the present, and the conditions are ready to go and grab the cube.
Now it’s time to move those platforms. Place the newly acquired cube on the ground where there’s a portal surface, then go to the future and bring its future self back to the present. Next, use portals to bring the light bridge to the laser at the top of the room. There’s an obvious portal located on the wall above the button area, surrounded by non-portal surfaces. Bring the future cube through the portal and place it in front of the laser, blocking its path. Make sure that the cube is placed directly above the large ground button, then step on the first platform. Remove the portal keeping the future cube in place, and the platform will rise because the laser is no longer blocked. Without the light bridge, the cube will fall onto the big button below, moving the second platform in range for the player to jump on. Once on the second platform, relocate the present cube by shooting a portal underneath it. This will cause the future cube to vanish because of the change in its past, meaning the big button is no longer weighed down, and the platform the player is on will rise up to the finish gate.
Portal Reloaded, the mod for Portal 2, is available on PC.