The Testing Grounds

Strange physics

An underground facility, sealed for forty-one years, where a warm voice would like you to take a test.

At a glance

Kind of world	Strange physics
Serum in the arrival Box	2 ampoules
Native Serum stand-in	Stasis Mist
Quests	Yes: see your Traveler's Guide

Screenshot comingtesting-grounds-arrival

Waking in the glass cubicle of the Relaxation Vault, white panels and a lit corridor beyond the glass

What happens when you arrive

You wake up in a glass cubicle in the Relaxation Vault of the Apertune Science Enrichment Center, an underground test facility that has been sealed for forty-one years. A warm, slightly unsettling voice welcomes you back from stasis, tells you that is "within tolerance", and promises you cake. That voice is GLaDYS, the computer that runs the place. A door opens in the glass, and the test track begins.

This world is a puzzle story. It has no monsters and no wilderness: just test chambers, a portal gun, and a lot to find out about who built all this and why the door at the top never opened.

The rule: the facility is a test

What changes	What it means for you
You can't break or build here.	The facility stays whole. The only blocks you can break are the Loose Panels (scratched panels that lead behind the walls) and the Stasis Mist Canisters in the vault corridor.
Nothing spawns.	No mobs at all. The only things that shoot at you are turrets in the chambers.
Dying is a test result.	You come back at the start of the last chamber you walked into, facing in, with your gun and boots.
Time is frozen at noon.	The lights never change. Beds don't work (the vault cot is for show).

The portal gun

In chamber 03 the Apertune Handheld Portal Device waits on a pedestal under a spotlight. Take it, and you are also fitted with Apertune Long Drop Boots: worn, no fall ever hurts you, and they never wear out.

Control	Does
Left-click	Fire your first portal (blue).
Right-click	Fire your second portal (orange).
Sneak + right-click	Pick a colour pair (in multiplayer, each player claims their own of 8 duos; solo, it is always blue and orange).

• You own one pair. Firing a colour again closes the old portal of that colour.
• Inside the facility portals only stick to white panels. Dark panels, glass and machinery refuse them. Reading which walls are white is half of every puzzle.
• Momentum carries through: fall into a floor portal and you fly out of the wall portal just as fast. GLaDYS calls it "speedy thing goes in, speedy thing comes out".
• Anyone can walk through anyone's portals.
• Take the gun home and it works anywhere on any solid full block. A pair can even span two worlds, but you need Serum Active to cross, just as with a door. Portals never open into the Corridor.

Screenshot comingtesting-grounds-fling

Mid-fling: flying out of an orange wall portal over a pit, the blue portal in the pit floor below

The test elements

Element	What it does
Weighted Storage Cube	Right-click to pick it up (it floats in front of you), right-click again to set it down, left-click to throw. Holds down buttons. Held up, it is a shield.
Heavy-Duty Super Button	A floor button. Opens its door while something heavy sits on it.
Pedestal Button	Press it. Usually drops a cube, pours gel, or opens a door for a few seconds.
Thermal Deterrence Beam Emitter	A red laser. Standing in it costs 4 health about twice a second. Steer it with portals into a Beam Catcher.
Reflection Cube	A cube with a lens: set it down in a beam and it turns the beam the way it faces.
Hard-Light Bridge Emitter	A walkway of light. Holds you, cubes and turrets. Portal it somewhere useful.
Aerial Trust Plate	Step on it and it throws you (and whatever you carry) across a gap.
Repulsion Gel (blue)	Land on it and you bounce back up as high as you fell, with no fall damage. Sneak to land without bouncing.
Propulsion Gel (orange)	Run on it to go 1.6 times as fast. Sprint and jump at the end.
Expedition Funnel Emitter	A blue tractor beam that carries you or a cube slowly along it.
Material Liberation Grill	A shimmering doorway. Walk through it and your portals close and whatever you carry dissolves.
Incinerator	Feeds on cubes. One chamber will ask you to put something in it.
Turrets	White eggs on three legs. Step into the cone in front of one (20 blocks, 60 degrees either side) and it says hello and opens fire. Anything solid between you, a held cube included, stops the shots. Knock one over (hit it, throw or shove a cube at it, sprint into it) and it sprays wildly and shuts down. You can carry them too.

Your quest: The Test Track

The quest tracker walks you through it, with a compass pointer to the next place.

Step	What to do
1	Leave the Relaxation Vault.
2	Finish the orientation and enrichment chambers, 1 to 13 (the gun is in chamber 03).
3	Finish chamber 14 with the Weighted Companionship Cube.
4	Get the cake (chamber 15).
5	Follow Wheatlee's rail behind the panels.
6	Walk the Old Wing and hear the founder over the PA.
7	Find the filing room.
8	Go and see her.
9	Finish every chamber, then put your hand on the plate by the Surface Door (or pick another ending).

The chambers

Chamber	What's new
01	Portals, placed for you. Walk through, press the pedestal, leave.
02	Cube on the button.
03	The portal gun.
04	Momentum: drop into the pit, fly out of the wall.
05	Aerial Trust Plates.
06	Everything so far, together.
07	The beam. Portal it into the catcher; don't stand in it.
08	The Reflection Cube. A dark floor tile marks where to set it.
09	The Hard-Light Bridge.
10	Three turrets. Use a cube as a shield, or portal in behind them and knock them over.
11	Repulsion Gel.
12	Propulsion Gel. Sprint! The ladder in the gap is for those who didn't.
13	Funnel and Grill: float the cube through the hole in the glass, then walk through the grill.
14	The Weighted Companionship Cube.
15	The cake.
16 to 18	The Old Wing: a cube room, a timed beam, a trust plate over flooded water.
19	Her chamber. Everything at once.

Screenshot comingtesting-grounds-turrets

Chamber 10: three white turrets behind a low wall, one opening its gun wings

People you will meet

• GLaDYS, the facility's voice and, later, a great arm hanging from the ceiling of her chamber with a single lens. She comments on everything you do.
• Wheatlee, a small round core with one blue eye who slides along a rail in the ceiling. He first appears in chamber 07 and whispers help. Behind the panels he leads the way.
• Doug, the last test subject, is long gone. His drawings cover the walls behind the panels, arrows showing the way out that he never took.
• The founder, on tape. Eight tapes play in the Old Wing (use a Tape Player). They explain a lot.

What happens in chambers 14 and 15 (spoilers)

In chamber 14 GLaDYS insists the Companionship Cube goes in the incinerator; the exit opens once it does. But there is a loose panel in the corner beside the incinerator. Carry the cube behind it and the cube is yours for good: it becomes a companion that hovers behind you, sits on buttons when told to stay, and can be carried and thrown. GLaDYS notices and says nothing.

Chamber 15's floor is a conveyor belt carrying you towards a pit of fire, with the cake in a case beyond it and a door that never opens. Portal one of the low white runs just before the fire and the white run high over the ledge, and step off the belt into the low portal. The hole in the wall by the ledge leads behind the panels.

The truth and the deal (spoilers)

Behind the panels, Wheatlee leads you to Doug's den, then through the Old Wing (the founder's tapes and the old science fair) to the Offices. In the filing room, a drawer with her name on it holds Apertune Directive 1: the Surface Door opens only for a finished test track and a hand on the plate. Nobody ever finished. GLaDYS has been running the chambers empty for forty-one years. She goes quiet for a while.

When you walk into her chamber (19) she offers a deal: finish the track with her, the last chamber she built around herself, and put your hand on the plate.

The three endings

Once she has offered the deal, the tracker shows all three. Only one ending per server, forever: the first player to choose sets it for everyone.

Ending	How	What you get
Walk Out Together	Finish all 19 chambers, then use the Hand Plate by the Surface Door.	The facility lights up, the Surface Door opens, and GLaDYS rides home with you in a potato jammed on your portal gun, as a talking companion. The extra-credit wing opens.
Shut Her Down	Use the Core Socket under her dais.	The Surface Door opens. She is silent from then on, the panel lights go dark, and Wheatlee is left running the lights.
Stay and Test	Use the Head of Testing Desk.	You get the Head of Testing Badge, the Surface Door opens, and she starts building new chambers for you.

What each ending looks like (spoilers)

Walk Out Together: she has never seen the door open ("It's smaller than I thought"). You chose the science-fair potato over the mainframe, and she will never let you forget it. The potato GLaDYS follows you through the Corridor and has something to say about every world you take her to.

Shut Her Down: she stays calm to the end, and is cut off mid-word. The cake waits on a plate by the exit with a card.

Stay and Test: "Nobody stays." She makes you a badge machine to make the badge. From then on, the desk asks her for a fresh set of chambers whenever you like.

Screenshot comingtesting-grounds-gladys

GLaDYS's chamber: the great arm over the dais, the hand plate and core socket beneath, a light bridge across

After the ending

• The Surface: ride the lift up through the Surface Door to a sunny wheat field with a shack. By the shack wait a Companionship Cube to take and a chest with 4 Rescue Beacons, your way home.
• The cake is real. After Walk Out Together or Stay and Test, the Refrigerated Cake Case opens for you once: a Slice of Cake (8 hunger, and Regeneration II for 10 seconds).
• Extra Credit (after Walk Out Together or Stay and Test): six chambers off GLaDYS's gallery. Four are a fixed course played in order (Up and Over, Relay Race, Ferry, Gauntlet); the other two are rebuilt from a new layout each visit. Every one has a cake behind its door.
• Leaderboards: the Leaderboard Screen keeps best times and fewest portals for every chamber.

What to bring home

Find	Where	Why it's worth it
Apertune Handheld Portal Device	Chamber 03.	Portals anywhere at home, on any solid full block.
Apertune Long Drop Boots	With the gun.	No fall damage, ever. Unbreakable and fireproof.
Stasis Mist	Break the six canisters in the vault corridor (1 or 2 each).	The Serum stand-in (below).
Facility blocks	Craft them.	White and dark panels, lights and the test elements themselves, to build your own chambers.

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➜8

White Panel (Crafting Table)

BO

➜

Weighted Storage Cube (Crafting Table)

RD

➜

Reflection Cube (Shapeless: any arrangement)

BSBD

➜

Repulsion Gel Bucket (Shapeless: any arrangement)

BSOD

➜

Propulsion Gel Bucket (Shapeless: any arrangement)

Dark Panels are a White Panel plus black dye; Panel Lights a White Panel plus glowstone dust. Every test element (buttons, doors, droppers, beams, bridges, plates, funnels, grills, the incinerator) has a recipe built from White Panels and iron.

Serum and getting home

• The arrival cache holds 2 Serum Ampoules.
• Native stand-in: Stasis Mist, the gas that kept subjects asleep for decades. It replaces Somnium Powder in the Synthesizer. Six canisters line the vault corridor; break them.
• The facility's own way out is the Surface Door, which only opens after an ending. The Rescue Beacons in the chest by the shack take you home from the field.

Tips

• Stand at the back of a room and look for the white panels first. Most chambers have only one or two.
• Don't carry a cube into a Grill. It dissolves, and your portals close too.
• In chamber 15, place your portals early, while you still have belt to spare.
• The loose panel in chamber 14 is your only chance at the Companionship Cube. Take it there.
• The ending is shared by the whole server. Talk it over before anyone touches the plate, the socket or the desk.

Everything this world adds

76 blocks and items (click to open)

White Panel

Dark Panel

Panel Floor

Panel Light

Old Panel

Cracked Old Panel

Observation Glass

Loose Panel

Warning Panel

Vent Panel

Facility Concrete

Facility Pipe

Catwalk

Office Wood Panelling

Shag Carpet

Office Ceiling Tile

Dead Screen

Pictogram Sign

Rattmin's Drawing

Lift Tube

Lift Pad

Drop Tube

Management Rail

Conveyor Floor

SMStasis Mist Canister

VRVault Radio

RCRefrigerated Cake Case

TPTape Player

FCFiling Cabinet

SCSecurity Camera

HPHand Plate

CSCore Socket

HOHead of Testing Desk

Leaderboard Screen

SFScience Fair Potato

Surface Door

PDPortal Device Pedestal

VCVault Cot

VCVault Cot Foot

VTVault Toilet

PPPlastic Plant

ODObservation Desk

AOApertune Office Chair

LLocker

CCCoffee Cup

Heavy-Duty Super Button

Pedestal Button

Chamber Door

Cube Dropper

Thermal Deterrence Beam Emitter

Beam Catcher

Beam Relay

Hard-Light Bridge Emitter

Aerial Trust Plate

Gel Dispenser

Expedition Funnel Emitter

Material Liberation Grill

Incinerator

Chamber Wire

Repulsion Gel

Propulsion Gel

Hard-Light Bridge

Expedition Funnel

Stasis Mist

Slice of Cake

Head of Testing Badge

Apertune Directive 1

Apertune Long Drop Boots

Weighted Storage Cube

Reflection Cube

Weighted Companionship Cube

Repulsion Gel Bucket

Propulsion Gel Bucket

Decorative Turret

Apertune Handheld Portal Device

SpudOS Potato

The traveler's tape

Every arrival Box has a chest by its door holding a cassette: the last traveler reading their journal of this world aloud. This is what they say. It gives a lot away.

Read the journal (spoilers)

There's a voice here that keeps promising me cake. I've done eleven rooms. I don't think there's any cake. I think she's lonely. I'm going to do room twelve anyway.