Test Chamber Design Tips

Design better test chambers with these hints.

Overview

The following is a list of guidelines for making good test chambers. They are not hard and fast rules. Violating one of these rules does not automatically make a chamber bad. However, chambers which are considered to be good tend to have these traits in common. Valve usually follows these principles in the game's canon chambers.

I will also make the disclaimer that my test chambers violate some of these rules a fair amount. This is mostly because they were designed a long time ago, before I learned a lot of these guidelines. Perhaps I should make some more chambers!

Play Chambers Made By Other Players

This will give you inspiration for your own ideas and help you get a sense of things that make good chambers. Of course, don't just rip off someone else's chamber wholesale. Adapt it and make it your own.

Think of a Central Concept

The most successful chambers tend to be oriented around a particular concept that combines two or more testing elements, such as using faith plates to launch things into funnels, or using pivot cubes to direct lasers to guide a cube to a particular location. Figure out what the central concept for your chamber will be, then think about interesting ways to use that concept.

Design Backwards From the Goal

The goal for all PeTI levels (and most non-PeTI levels) is to walk through the exit door. Often, the door starts out closed, so the player must figure out how to open the door, then get to it. Start with designing how the player opens and reaches the exit, then add more complexity with additional puzzle elements that serve as obstacles to those goals.

Give the Player an Easy Starting Goal

Players are more easily discouraged when they feel that they have made no progress at all. For this reason, it's often beneficial not to hit them with the hardest part of your chamber first. Give them something easier to start out with so that they have the satisfaction of having made progress to help them get through the harder parts.

Introduce Any Novel Concepts

If you are using a concept that wasn't highlighted during the canon game, it might be a good idea to introduce the player to the concept in a simple "tutorial" chamber before letting them into the real one. For the tutorial, strip away all other elements which might distract from the new concept to be learned. Make sure the player cannot proceed until they demonstrate understanding of that concept. You might make several tutorial rooms which gradually increase the complexity by adding a new wrinkle to the concept.

Difficulty Should Come From Solving Puzzles

Portal is primarily a puzzle game. The people attracted to this game generally get enjoyment from the "aha" moment they get from figuring out how to solve a puzzle. If the player encounters difficulty that does not come in the form of a puzzle, they may find it annoying and/or think your chamber is badly designed. Avoid creating puzzles that require split-second reflexes or that rely on fiddly physics. Some examples include:

• high-precision shots (especially under time pressure or while being lobbed through the air)
  
• precision platforming (including climbing stacked objects)
  
• exploiting glitches
  
• ambushing the player with deadly traps
  
• turrets or timers that aren't carefully designed as part of the puzzle
  
• having so many turrets open fire at once at the player that they have no time to run for cover

Make Puzzle Features Visible

Chambers should be designed such that the puzzle features are readily visible to the player. This means providing adequate lighting and providing clear line of sight to important objects, especially between objects which are connected. Hiding things just results in players wandering around trying to find things instead of solving the puzzle, which isn't fun. With many of the best chambers, you can see nearly the entire chamber from anywhere in it. Use the architecture of the room and especially lighting to call attention to important elements.

It's especially helpful for the exit door be visible to the player from the start. This is because players will often start by looking for the exit, then trying to work backwards from it to figure out what they need to do to open and reach it.

Death Is Annoying

If a player dies, they have to wait for the chamber to reload before they can continue playing. After dying a few times, the player is going to get annoyed. Generally, failure is preferable to death, so it's not particularly desirable to have death around every corner of your chamber. Avoid overelying on elements that can kill the player: goo, turrets, and death fields.

It's especially bad to "ambush" the player with death if they don't act immediately in response to an unanticipated threat. For example, a player might step on a button which causes a wall panel to open which exposes them to a previously-unseen turret. If something can kill the player, it's best to make it so that they can see the danger while they are still safe, and have time to determine what to do about it.

Avoid Overcomplicating Things

It's tempting to throw everything and the kitchen sink into a chamber, but this tends to make it too complicated for players to try to figure out what they're supposed to do. Try to limit the total number of objects. You can also break up the chamber into sections or hide elements they don't need yet to avoid overwhelming the player.

Don't Let The Player Get Stuck

If there is any way for the player to get into a situation where the only way to continue is to kill themselves or restart the level, you messed up. Here are some examples:

• The player falls into a pit in which the only accessible portalable surfaces are inside the pit. (The player can get stuck if they don't already have a portal that is outside the pit.)
  
• The player stands on a button to open a door, then portals through the door into a room that has no other way out. They then touch a fizzler while inside that room.
  
• The player obtains a cube, then brings it into a room in which they will need the cube to escape. They then accidentally lose the cube.
  
• The player accidentally paints a cube with repulsion gel that they are required to place it on a button to open the exit door, and there's no water to clean it off and no way for them to get a replacement.

To avoid this problem:

• Always make it so the player can escape from any room. For example, you can make a timed button that briefly opens a way out.
  
• Always make it so that players can recover lost objects or get replacements.
  
• Provide water to clean gel off of cubes.

Create Clear Connections Between Devices

It should be obvious what a device (such as a button or a laser receiver) does when you activate it. There are three ways to associate a device with the thing it activates:

Antlines

This is the preferred method, as it provides a clear visual connection between them, which lights up when it's activated. It's especially helpful if the two devices are far apart, because the player can trace the antline from one device to the other. However, this requires there to be a continuous wall (or floor or ceiling) between them, which isn't always feasible. Also, avoid having too many antlines running close to one another, since it can make things confusing.

Signs

If antlines aren't workable, you can use signs. Each device is marked with a sign with the same shape on it. Unfortunately, with signs, it's less obvious when the device is activated, and there's no trail to follow.

Proximity

While it's preferable to use antlines or signs, you can sometimes make clear the association between devices by putting them next to each other. For example, a pedestal button located directly under a cube dispenser is a pretty clear indication that pressing the button will dispense a cube. When possible, it's a good idea to put connected devices near each other even if you are already using antlines or signs. Be careful not to violate this expectation, though. Don't put things close together in a way that would indicate a relationship when there isn't one.

Tune Your Timed Puzzles

A timer should "break" the obvious approach to a puzzle by making it take too long to do, therefore requiring them to find another way that doesn't take as long. For example, a timed button may open a door that is too far away to reach by walking before it closes again, so the player must find a way to flip a panel near the exit so they can portal over there instead to save time.

Chamber designers make two mistakes with setting timer duration:

• Setting the timer length to be just barely long enough for the intended solution. Players get annoyed when they know how to solve a puzzle but actually executing the solution requires sub-second precision.
  
• Setting the timer length to be just barely too short for the obvious solution. This may lead the player to believe that they have found the correct solution, but are just not executing it fast enough. This may result in the player attempting the wrong solution multiple times.

Any timer that is used should have its duration tuned so that it is clearly too short for the obvious approach, yet generous for the intended solution.

Also remember that turrets are a timed element: the player has only a short time before they open fire, and the more that are shooting at them at once, the faster they will die. Don't use more turrets than needed for a puzzle.

Don't Make It Tedious

If the player has to do the same thing over and over, or walk long distances, they will get bored. Big chambers look cool, but result in lots of walking, so avoid making chambers bigger than they need to be. If a space must be large, try to provide convenient portal surfaces or faith plates so that the player can quickly cross the chamber without having to hoof it across. Mazes are even worse, packing more walking into a smaller space; don't do them.

Be wary of making chambers where the player's progress can be completely reset with one wrong move. For example, if a player has to navigate to the top of a very tall chamber, one false step may send them falling all the way to the bottom. Nothing triggers a rage quit quite like spending a long time getting close to the end, only to find yourself all the way at the start again due to a simple mistake. If you make a larger chamber, provide autosaves if possible. When a player solves a time-consuming puzzle to get a cube, avoid requiring them to redo it all if they accidentally lose it.

Don't Make Red Herrings

Every element in the chamber should have a purpose. If a player expends a bunch of effort trying to figure out how to use a test element that turned out to have no purpose, they will be annoyed, or think that your chamber is broken.

Re-use Test Elements

A good way to add interesting complexity is to require the player to re-use certain test elements. It can be a satisfying experience for the player to figure out how to use a test element for more than one part of the puzzle.

Carefully Manage Portal Surfaces

If all surfaces are portalable, the player doesn't get hints about where they should place portals, and you may inadvertently make exploits that allow people to skip parts of your puzzle. On the other hand, if you only make portalable the surfaces that require it, you may end up making the chamber too easy. Make sure that portal surfaces can only be shot from intended locations. Unexpected angles to portal surfaces give rise to exploits. Use non-portal surfaces, glass, movable panels, or emancipation grills to block access to portal surfaces from unintended locations.

Keep Things Out of the Player's Way

Some test elements have a tendency of getting in the player's way if they are not placed carefully, particularly lasers, funnels and light walls. Avoid requiring the player to go through a portal or other narrow area while a laser or light wall is passing through it. Don't place objects so close together that the player doesn't have walking room around them.

Use the Right Material

Glass is easier to see through than gratings, so use it whenever you can if a player needs to be able to see through a barrier. If the player needs to be able to shoot through it, use a glass wall with a hole in it if possible. (This is not available in vanilla PeTI.) Gratings are best used when a player needs to be able to shoot through a barrier without being square with it.

Careful With Funnels

One of the most common mistakes players make with excursion funnels is unintentionally picking something up with one (including themselves). Try to design your chambers to reduce the chances of this happening.

Careful With Gels

It is very easy to get gel on things you didn't intend.

• If you get repulsion gel on unintended surfaces, it can be annoying to the player, because they will have to remember to hold Ctrl if they don't want to bounce. Worse, if they accidentally paint a cube with it, they won't be able to put it down. Always include water in chambers that have repulsion gel so players can wash off painted cubes.
  
• Speed gel is less of an issue, although slippery cubes can cause problems when they have to be placed accurately or on unlevel surfaces, so providing water is still a good idea.
  
• Conversion gel is prone to enabling exploits, because players often manage to get the gel somewhere you didn't expect.

Balls Roll

Players are often annoyed when they are required to put down a ball, since they tend to roll away if not put somewhere secure. If you must make players put down a ball, try to give them somewhere safe to put it where it won't get lost.

Use the Companion Cube Appropriately

The Companion Cube was introduced during a chamber in Portal 1, which required the player to bring the cube with them all the way to the end of the chamber. Valve specifically took steps to encourage the player to emotionally bond with it because play testers kept getting stuck because they left the cube behind.

Because of this, players have been trained to try to bring the Companion Cube with them throughout the chamber. If the player needs to keep reusing a cube all the way to the end of a chamber and not leave it behind, make it a Companion Cube to signal this to the player. Otherwise, do not make it a Companion Cube.

Also remember that the Portal storyline gives the Companion Cube emotional weight. This weight is reduced when there is more than one Companion Cube at a time, so it's generally best to have only one if you use it at all.

The Companion Cube may also be a fun Easter egg. In this case, it should be made clearly worthless for solving the chamber, typically by making it obviously unreachable.

Playtest

Have people try out your chamber. They may find exploits or ways of getting stuck you hadn't considered.

Did You Like This?

Consider giving my guide a like and a favorite, and sharing it with others. If you really like it, an award is a great way to show your appreciation. Have a look at my other guides.

License

This document is licensed under Creative Commons BY-NC-SA 4.0[creativecommons.org].

[jlemoyne5]

thank you very much. I've been looking for a guide like this for a long long time!
PS. Do you have a guide for visuals? thanks!

[Pnezyx]

great guide i will definitely recommend this to my friends

[Dark Rozen]

This is a well written guide. Thank you.

[Faye_uwu]

This was very helpful. I just got around to making my first chamber and I definitely could learn from some of these tips. Sidenote, does anyone have any tips or guides for designing a level visually?

[TurboDiego]

This guide is amazing. Thanks!

[Courier]

great words of wisdom.
the word great means "giant".

[Robert the cat]

actually more like 1442 or 1332 or 1443 or 1224 or 1222 or 1223 or 1221 or 1111 or 111 wait not 111 defintly not 111

[Robert the cat]

how many words are in this? at least 14432

[baraaeesa2012]

at the beginning you said its short but its like 20 riddles

[seaque]

great guide. thanks.