wiki/Leveldesign.md

These guidelines should be kept for any level that appears in the main SuperTux level sequence. Any deviation should be rare and with great consideration (for example for a secret area). Designers making custom levels intended for an Add-on or Bonus Island are free of regulations - that's what those sections are for. However, keep in mind that if your levels violate too many of these suggestions people will likely find them not very fun.

Setting

In Milestone 2, will have Icy Island as game discovering area, the island already present in Milestone 1. It has a snow and ice setting, so please use the appropriate tiles only. Most of them are in the “Snow” and “Blocks” groups in the level editor. There are numerous other tiles currently available in the editor, but they are either either not finalized (e.g. ice mountain) or not appropriate for Icy Island. In that first world, only basic elements should be found. It will present a revised Forest, where more elaborate elements may be found. The Boss have to be designed. And eventually a third world (proposed to be Tropical_Island) with the Fun Pif quest. Please Note that Neither art or code is ready yet for this part, then you shall not design any level with their elements already available.

Difficulty

The goal of SuperTux is to be fun, not to be hard. So the goal is to make fun levels, not to make them challenging. Remember that a player will get frustrated and annoyed if he dies more than small number of times in a level and also keep in mind that a player will see the level for the first time when he plays it.

Tip: If you are in doubt if a level is getting too hard, change the style of play to something that is unfamiliar to you, invert left/right controls, play with the left hand, play only as small Tux or anything like that. If you can still beat the level without problems and without dying, it likely is easy enough. If not, then it is likely too hard.

Enemies

Do not randomly mix enemies of all different kinds. Level should follow a certain theme and thus focus on enemies that fit that theme. For example, fire enemies should only appear in castle levels. In addition, don't just randomly place each and every type of snow enemy into a level- pick a few enemies that best fit into your level.

Be mindful of how enemies react to the environment when deciding where to put them. For example, snowball will always fall off ledges while smartball will always turn around at a ledge, thus snowball is a poor choice in a sky level where smarball is much more appropriate. Enemies should not fall off the screen before players have a chance to engage them, and it should be possible to fill out the badguys killed stat. Finally avoid placing enemies where they will reach a spawn point. This is most important around the level start and reset points, as there should be ample time for a player to see and assess the level before being forced to act. Levels that switch back-and-forth between sectors are also prone to having an enemy wander into a spawn point resulting in Tux being hurt immediately after spawning- this is bad and makes players sad.

Slopes

When creating slopes, make sure that they are smooth and don't make sudden jumps in inclination. Note when using slopes that some combinations are ill-fitting; ignore these artifacts as they are graphics problems, not level problems. You may want to avoid the use of steep slopes for the time being, at least until the slope collision physics are improved some more. Along those same lines, the placement of slopes directly next to a vertical wall currently produces some bizarre behavior and should be avoided until the mechanics are improved.

Tiles

Don't use tiles in the background that were built for the foreground. Use only special background tiles in the background. In general, don't ever mix tilesets. Clearly distinguish between the layers - players should be able to see immediately where they can safely walk and what is foreground and background. Secret areas can violate this.

Size

Levels must be at least 25 tiles high, and using at least 32 tiles is recommended. Levels should be between 250 and 350 tiles long. (A couple of levels in Icy Island are over 500 tiles long – newer levels should not be this long and it's possible we'll split up those long levels in the future.) Any vertical scrolling sector should be no narrower than 40 tiles wide to ensure it displays well in every resolution setting currently supported by SuperTux.

File Naming Conventions

When saving the level file, stick with the convention used for the worldmap. For example, Icy Island levels are named like this: 02 - example level.stl where the number (02 in the example) showing what order you play the levels, and the level name are separated by a hyphen. The level extension is .stl, if you forget the extension, the level will not be recognized. If you need an example of naming convention, look at the data/levels/world1 directory. If level order does not matter, or is unknown, the number and hyphen can be omitted.

Note: having spaces in the level names makes command-line manipulation of files for development atrocious, there should probably be a discussion about changing the convention to use underscores in the level names instead.

However, it's not critical that custom levels necessarily follow the same naming convention. It is nevertheless best to stick with a non-cryptic naming scheme where it is obvious which file is for which level.

Sectors

When making a level, use floors and ceilings where appropriate. Basic rule of thumb is that your environment should visually make sense. For example:

• Overground areas should have a floor and no ceiling.
• Underground/cave and interior areas should have both a floor and a ceiling.
• Sky area should have neither a floor nor ceiling.

Transitions between sectors should also make sense. Having Tux walk off a screen of overground ice and suddenly appearing in the middle of a castle is confusing. Also one-way sector transitions should only be used where it is logical, such as dropping down a hole. Doors should be two-way. Sectors designed to be next to each other should be able to be visually connected.

Other

SuperTux is meant to be a fair and fun game, so don't create unfair configurations, like a spike on the roof as well as one on the ground, that require way too much precision or luck and just aren't fun to play.

Other things to avoid:

1. Creating paths that are only two tiles high, make things high enough that SuperTux can jump.
2. Don't create jumps that require pixel perfect precision unless it is for a special secret area.
3. Don't use invisible tiles for normal gameplay.
4. Keep the number of enemies that are on the screen at once small, it shouldn't be more then three for most cases.
5. Do not overuse switches and doors: SuperTux isn't an adventure game, it's a jump'n run, so make the level straightforward and easy to understand.
6. Avoid creating large monotonous spaces; players get tired of running around a huge level.
7. Try to limit the use of reset points; if you can get away with none whatsoever, do so.
8. Don't allow dead ends or impossible levels; either the player dies, or there's still a way to solve it. (Allowing the player to suicide from a trap works as well) Test your level thoroughly to find possible paths you missed before.
9. Avoid too hard or too easy levels. Too easy levels get boring very quickly while too hard ones can be frustrating. Levels you built often appear a lot easier for yourself, so be sure to let other people test them.
10. Secret areas should be well-hidden and not be visible on first sight, but can still have a visual cue that they are there. Use your imagination to think of new ways to create secrets - some of the above rules can be broken for that purpose, but be careful!
11. Avoid impossible-to-reach coins, powerups, areas, and badguys. Collecting everything or reaching everywhere in a level is often important to players. However, difficulty can be just short of impossible - requiring frame-by-frame accuracy is fine. (So long as you provide a demo to prove that it is in fact possible) This only applies to bonus items - players should be able to complete the level minus some items with only moderate difficulty.
12. Avoid using any water. Swimming and water physics have not been finalized, so any current water behavior is unreliable.
13. Avoid using very steep slopes or placing slopes next to vertical walls, the collision physics is still a bit off.
14. Don't overuse “new” things (enemies, objects, tiles): Use them when and where they make sense. Don't use them just because they are new.
15. Change gravity only when it has sense. Don't change it, when you want only Tux jumping higher/lower.

Secret Maryo Chronicles

The Secret Maryo Chronicles wiki (now defunct) had some good guidelines. They are reproduced here (GDFL 1.3+ license)

• The level filename must be all lowercase and without spaces but underscore "_" is allowed.
• All types of text should be written in American English.
• Test your level thoroughly and let friends play it. Make sure every part isn't too hard, every jump is as far as you want it to be, nothing can be accessed easier then you intended, and all your secrets work.

General

• Beginning Safehaven: Give the player a safe space to start the beginning of each level. If a player dies less than 5 seconds after starting, they're more likely to quit.
• Ending Safehaven: Try to avoid putting enemies right near the exit door. Dying right at the end of a level is frustrating!
• Even Difficulty: Try to aim for a fairly even difficulty throughout level. If you want an extra difficult part, make it a sub level, connected by pipes.
• Bonus Independent: Hidden secrets and bonuses are good, just don't generally make a level dependent on them to avoid frustration. A player who missed the bonus should still be able to get through (see Always Winnable below).
• Beginner Friendly: Avoid essential objectives that require very high or long jumps. Just because you can make them, doesn't mean everyone else wants to.
• Always Winnable: Avoid making levels potentially unwinnable if a player does something wrong. If an item is essential, it should come out infinitely; if a player falls off a platform, it should return; if a player walks past something important, they should be able to get back there.
• Indicate Direction If the way forward is not obvious, clues should be given to encourage exploration. If a player is required to fall off a ledge to an area below the current camera position, a visual clue should be given that it is safe, like some coins in the shape of an arrow.
• Off Path: Encourage exploration away from the central path with non essential bonuses.
• Even Ground: Try to make the ground either flat, or very obviously raised. It confuses the player if Maryo suddenly stops because of a ground tile 1 pixel higher than the one before.
• Passive Filler: Never use massive objects in areas that can't be touched by the player. It puts unnecessary strain on the game and on computers. For large massive areas (especially ground), use a single row of massive around the whole outside of the shape, then passive or Front passive inside.
• Enemy Visibility: Take care when using Front Passive objects to ensure they never completely cover any enemies. If you want a section where Maryo appears behind the scenery, don't put any enemies in it.
• Easy for Kids: Use the Textbox only if necessary as a player may have a limited knowledge of the English language or even none at all.
• Consistently Solid: Don't abuse Massive Types. We all know that you can make a castle you can walk straight through, or clouds you can walk on, but that doesn't mean it's fun to constantly switch between passive and massive for the same objects. It should be obvious which parts are solid and which parts are decoration, otherwise it's very frustrating (examples).
• Minimal Space: Always leave some free space vertically in small corridors for big Maryo and never require to be small Maryo to reach an Area.

Optional

• Difficulty Filler: Look at what levels exist and try to fill in the "difficulty gaps" with yours. Often this may mean creating easier levels.
• Clear Direction: The player should always have a clear idea of which way to go and what to do, the challenge should be in doing it. This is called the central path.
• Stable Only: Try and show off new features, but only ones that are in the latest stable version.
• Learning First: Make sure that there is an easy level that encourages learning any new skill safely before challenging players with a level where they die if they do not use that skill successfully.
• Bonus Clues: Use small clues to hint at hidden secrets (e.g. a single coin otherwise unreachable). Should be visible if player is paying attention but not obvious.
• Jump Backgrounds: Make sure to use background graphics wherever the player would be jumping. Without backgrounds it can be hard to judge your speed and position.

Theming

The general rule of theming is to decide on a style in advance and then only add what fits with that theme. Avoid the temptation to think "more is better" by using nearly every enemy / background tile / secret type etc.

• Backgrounds: Generally try to stick to one visual theme per level. Pick one style of background tile and stick to it. Lots of scenery is good, but it should be consistent with the effect you want.
• Enemies: Select up to 4 types of enemies that best fit the level style and stick with those rather than using every enemy type available. Keep the custom settings (if you use them) of the visually equal enemy the same for the level to not irritate the player with different behaving enemies.
• Avoid using "boss" characters and use them only for very special parts or the end of an overworld.
• Use strong colored doors only for special parts of the level. The red door should be used for entering a boss area.

Ways of hiding bonuses and secrets

Enemy Assisted:

• Distance Bounce: Bounce on an enemy to reach a distant, normally unreachable platform
• Deadly Enemy: Stand / run on an enemy that normally hurts you (e.g. Thwomp, or invincibility on an Eato / Spike / Buzz)
• Enemy Breakout: Enemies break open new areas, e.g. turtle breaks blocks, Spike / Buzz removes Eatos

Bonus / Maryo State Assisted:

• Ghost Reveal: Ghost Mushrooms show hidden blocks that allow access to new area.
• Invincibility Reveal: Stars let the player run through obstacles that would normally kill them.
• Previous Levelup: Use of a certain Maryo type is needed, but this powerup is not in the level, i.e. players must have gotten and kept the powerup from a previous level. Use this only rarely and for special bonus secrets.
• Speed run: Maryo must still be in a certain state (e.g. Ghost / Star) by the time he gets to the end of a long section to be able to access the secret.
• Hidden item: An item is hidden behind an innocuous Front Passive object (such as a part of a wall). This can then create any of the state activated bonuses above.

Surprising Landscape Based:

• Pipe Exit: Pipes, pipes and more pipes that lead to hidden levels or otherwise not accessible parts of a level.
• Non-Deadly Fall: Fall somewhere that looks deadly but revels a secret / area.
• Invisible Ground: Invisible ground that allow you to access hidden secrets.
• Solid Background: Unexpected solid "backgrounds" are not solid except a few that look the same but can be used to get to hidden ground. Use this only extremely rarely.
• Partially obscured: Secrets or entrances to secret areas can be partially hidden behind background objects.
• Moving Platform: Moving platforms that the player only sees if they do something unusual e.g. if they just run through an area they never see the platform but if he waits, it moves onscreen.

Skill Based:

• Skillful Maneuver: Secret is visible, but requires an unusually skillful jump / maneuver to get.

Old Stuff

These guidelines should be kept for any level that appears on the official world maps. Designers contributing levels to the Contrib and Bonus sections are free of regulations - that's what those sections are for. However, to maintain a certain level of playability, official levels should be designed with these rules in mind:

1. Don't mix tilesets! There shouldn't be any ice or castle tiles in a forest level, unless there is an obvious reason (like transition into another area).

2. Clearly distinguish between the layers - players should be able to see immediately where they can safely walk and what is foreground and background. Avoid placing bonus items (coins, boxes) in the background.

3. Be careful not to create dead ends. Test your level thoroughly to find possible paths you might have missed before.

4. Use everything the engine offers - but don't place it all in a single level!

5. Avoid large amounts of objects and badguys on the screen at once as it greatly decreases playability. Also, your level might not be playable on slower machines anymore.

6. Find the right difficulty! Too easy levels get boring very quickly while too hard ones can be frustrating. Levels you built often appear a lot easier for yourself, so be sure to let other people test them.

7. Don't make your level too short or too long - good size largely depends on the level's overall design, so there's no general "good" value. In longer levels, make sure there are enough reset points, so players won't have to repeat large portions of the level.

8. Secret areas should be well-hidden and not be visible on first sight. Use your imagination to think of new ways to create secrets - some of the above rules can be broken for that purpose, but be careful!

9. Icecrushers (Krush and Krosh) should be able to reach their original position and shouldn't get stuck anywhere in the middle when rising.