Portal 2: Complete Guide

A guide to Portal 2's single-player and co-op campaigns: portal mechanics and puzzle-solving habits, every test element, a spoiler-light chapter outline, easy-to-miss achievements, co-op tips, and the best community content and mods to play afterward.

Researched September 2026 — current as of the June 2026 Valve updates (credits fixes, security fixes, Linux launch fix). The game is otherwise complete; check the linked sources if something differs.

Quick Start

• Momentum is conserved through portals. "Speedy thing goes in, speedy thing comes out." Falling into a floor portal flings you out of a wall portal at the same speed.
• Portals only go on white, flat surfaces. Dark metal, glass, and grates won't take portals. Look for white panels first when entering a room.
• Stop and look around. Most puzzles are solved by noticing one surface or element you missed. Stand at the entrance and scan the whole room.
• Everything is one idea at a time. The game introduces a new element, tests it, then combines it. If you're stuck, think about what the last new element does.
• You can't really fail. Deaths reset you to a nearby checkpoint in seconds. Experiment freely.
• Hold objects to carry them through portals. Cubes, spheres, and turrets can be carried and dropped through portals.
• Co-op is a separate campaign. It has its own story and characters, Atlas and P-body. Play it after (or alongside) single-player.
• Turn on developer commentary on a second playthrough. It's full of great design insight.
• Play community content after. The Perpetual Testing Initiative, workshop maps, and standalone mods like Portal Stories: Mel, Portal Reloaded, and Portal: Revolution extend the game for years.

Controls (PC defaults)

Action | Default

Move | W A S D

Jump | Space

Crouch | Ctrl

Blue portal | Left mouse

Orange portal | Right mouse

Use / pick up | E

Crouching while jumping lets you clear taller ledges. Co-op adds a ping tool and gestures. Check Options > Keyboard for their binds on your setup. Pinging a surface tells your partner exactly where you want a portal.

Test Elements

Element | What it does | Key trick

Weighted Storage Cube | Holds down buttons | The first thing to look for in any room

Companion Cube | A cube with hearts | Behaves like a storage cube

Redirection Cube | Redirects laser beams | Aim it at laser catchers

Edgeless Safety Cube | Sphere-shaped cube | Rolls. Used with sphere buttons

Thermal Discouragement Beam (laser) | Burns you and powers receivers | Portals redirect it. Lasers also kill turrets

Aerial Faith Plate | Launches you on a set arc | Portals can redirect the launch

Hard Light Bridge | A walkable light bridge | Portal it to put a bridge anywhere, including as a wall or shield

Excursion Funnel | A tractor beam that carries you | Polarity can reverse. Portal it to travel anywhere

Repulsion Gel (blue) | Bounces you | Coat floors and walls to jump high

Propulsion Gel (orange) | Makes you run fast | Long runways plus a portal fling = huge distance

Conversion Gel (white) | Makes any surface portalable | Shoot it through a portal to coat new surfaces

Turrets | Shoot you | Knock them over, block with cubes or bridges, or burn with lasers

Pneumatic Diversity Vent | Sucks up objects | Mostly environmental

Buttons and pedestals | Trigger doors and elements | Some are timed

Puzzle-Solving Habits

• Find the exit first. Then work backward: what needs to happen to open it?
• List every portalable surface. The solution almost always uses a specific one.
• Count the objects. If there's one cube and two buttons, something else must hold one down (a turret, a bridge, a funnel).
• Think about flow. Gels, lasers, bridges, and funnels all "flow" through portals. Ask where you want that flow to go.
• Flings. When a gap is too far, look for a high drop you can fall into. Momentum is the answer.
• Timers aren't the puzzle. Timed buttons usually mean you need a portal pre-placed so you can move fast.
• Take a break. Solutions often appear after you walk away for a minute.

Single-Player Chapter Outline (Spoiler-Light)

Chapter | Name | What to expect

1 | The Courtesy Call | Waking up, meeting Wheatley, getting a portal device

2 | The Cold Boot | GLaDOS returns. Classic test chambers with lasers and bridges

3 | The Return | More testing under GLaDOS

4 | The Surprise | Escape plans begin

5 | The Escape | Breaking out, turret sabotage, neurotoxin

6 | The Fall | Deep underground. Old Aperture, gels begin

7 | The Reunion | 1950s–70s test chambers with Cave Johnson

8 | The Itch | Wheatley's tests. Combining everything

9 | The Part Where He Kills You | The finale

Tips by stage:

• Chapters 1 to 3 teach portals, cubes, lasers, and bridges. Take your time.
• Chapter 6 to 7 is where gels arrive. Old Aperture rooms are huge. Look for gel sources and pipes first.
• Chapter 8 mixes everything. Many chambers have more than one solution.
• Chapter 9 is a scripted finale. Keep moving and use portals quickly.

Co-op Campaign

Two robots, Atlas (blue) and P-body (orange), each with their own two portals. That's four portals, which opens up puzzles impossible in single-player.

Courses:

Course | Theme

1. Team Building | Basics of four-portal play

2. Mass and Velocity | Flings and faith plates

3. Hard-Light Surfaces | Light bridges

4. Excursion Funnels | Tractor beams

5. Mobility Gels | Gels

6. Art Therapy | The Peer Review DLC course (free)

Co-op tips:

• Use the ping tool. Point exactly where you want a portal instead of explaining it.
• Use the countdown. Timed jumps are easier with the built-in countdown gesture.
• One person experiments while the other watches. Then swap.
• Split screen works on PC and was fixed in a February 2024 update.
• Play with someone you trust. Valve patched several co-op exploits in 2024 and 2025, and more security fixes in June 2026. Keep the game updated.

Achievements Worth Knowing

Most achievements come naturally from finishing the campaigns. A few are easy to miss:

Achievement | Requirement

Door Prize | Examine all the vitrified test chamber doors

Portrait of a Lady | Find the hidden portrait

Smash TV | Break 11 test chamber monitors

Final Transmission | Find the hidden signal in one of the Rat Man's dens

Overclocker | Complete Test Chamber 10 in 70 seconds

Preservation of Mass | "Break the rules in Test Chamber 07"

Pit Boss | "Show that pit who's boss"

Ship Overboard | "Discover the missing experiment"

Schrodinger's Catch | Catch a blue-painted box before it touches the ground

Pturretdactyl | Use an Aerial Faith Plate to launch a turret

Stalemate Associate | "Press the button!"

The quoted ones are deliberately cryptic in-game. If you want them in one run, look up their exact chamber on the Portal Wiki before you pass that chapter, since you'd otherwise need chapter select to go back.

Co-op has its own set, including several that need the gesture or ping tools and a specific partner action. Examples:

• Talent Show — never lose a cube in Chamber 6 of the Mobility Gels course.
• Friends List With Benefits — hug 3 different people on your friends list while playing co-op.
• Professor Portal — after finishing co-op, complete the Calibration Course online with a friend who hasn't played before.

Search the achievement list in Steam before your co-op run so you can do them in one go.

Community Content and Mods

• Perpetual Testing Initiative (Puzzle Maker) — a built-in editor for making and sharing test chambers through the Steam Workshop. Free.
• Steam Workshop — thousands of community chambers. Sort by top rated.
• Portal Stories: Mel — a full-length, free standalone mod campaign with a new story and voice acting.
• Portal Reloaded — adds a third portal for time travel between two versions of each chamber.
• Portal: Revolution — a large free mod campaign set between Portal and Portal 2.
• Thinking with Time Machine and Aperture Tag — other well-known mods with new mechanics.

Most mods are separate Steam entries that require you to own Portal 2.

Common Mistakes to Avoid

• Ignoring the ceiling and far walls. The key surface is often above you or across a pit.
• Assuming you need speed or precision. Portal 2 puzzles rarely require difficult execution. If you're trying hard jumps over and over, there's probably an easier idea.
• Forgetting that elements pass through portals. Lasers, bridges, funnels, and gel all do.
• Rushing through dialogue. The writing is a huge part of the game. Stop and listen.
• Spoiling puzzles too quickly. Give each chamber a few minutes before looking up a solution.
• Skipping co-op. It's arguably the best puzzle design in the game.

Advanced Tips

• Flings are all about height. The higher you fall, the further you go. Stack portal loops to build speed.
• Mid-air portals. You can shoot a new portal while in the air to change your exit point.
• Use bridges as shields. Hard light blocks turret fire.
• Paint with conversion gel through portals to create new portal surfaces anywhere.
• Speedrunners use tricks like crouch-flying and portal bumping. Watch a speedrun after you finish to see the game differently.
• Commentary nodes show how Valve playtested puzzles. Great for puzzle design fans.

FAQ

How long is Portal 2? Roughly 8 to 10 hours for single-player on a first run, plus several hours for co-op, depending on how quickly you solve puzzles.

Can I play co-op with a random player? Yes, but it's much better with a friend, voice chat, and the ping tool. Local split screen is also supported.

Do I need to play Portal 1 first? It's recommended for story context but not required. Portal 2 introduces its mechanics from scratch.

Is Portal 2 still updated? Valve pushes occasional fixes, most recently in June 2026 (credits and subtitle fixes, security fixes, and a Linux launch fix).

What should I play after Portal 2? Workshop chambers, Portal Stories: Mel, Portal Reloaded, and Portal: Revolution.

Is the Peer Review DLC included? Yes. The Art Therapy co-op course from Peer Review is part of the game.

Sources

• Portal 2 on Steam
• Portal 2 Steam news — 2024–2026 updates
• Portal Wiki — Portal 2 achievements