Post tutorial RSS Field Intensity Recurring Level-Design mistakes

Describing Field Intensity level-design problems and seeking for possible solutions.

Posted by on - Basic Level Design/Theory

In this article I want to analyze some problems I see in Field Intensity level-design, and also share the experience and caution other mod-makers against repeating our mistakes.

Probably such an article should be written by an outsider, not by one of the devs. But I've watched enough Field Intensity video walkthroughs to take notes of what has been done incorrectly.

The level-design is a quite broad term. It's not only about what the level looks like but also about how it's played. Overall I'm content with the visual side of most Field Intensity levels. But the other part, so called "level flow" is far from ideal in the mod. Let's take a look at the recurring problems of Field Intensity levels.

Lack of visual feedback

The player must understand the effect of their interaction in the game world. E.g. if pressing a button results in some change (like a door getting opened), the effect must be clear to a player. Having visual feedback might seem to be an obvious rule in level-design, but you've probably seen a lot of mods and even full games that break this rule sometimes. And Field Intensity is not an exception.

Example: scientist in Bio-labs

Scientist open doors in bio-labs

The problem

In the end of his long speech the scientist pushes a button on the terminal to open the doors. However these doors are way behind the player's path and the player can't immediately see the result of the scientist's action. It would be much more obvious if the scientist opened the doors that are right in front of the player, but that's not how the level is built. This mistake happened due to the long development history.

The fix

If we insist upon perfection, this part of the level must be redone completely. However it's not an easy task once a level is almost ready. To mitigate the issue we've added some headcrabs spawns back in the corridor to make a player fight them and eventually follow to the right passage. In version 1.1 there's also a houndeye that is going out the room to highlight even further that the passage is open now.

Example: the lever in the Gamma labs

Gamme lever

The problem

Another example of discontinuity between the action and its result. The player pulls the lever but they don't see that the electric charges, that blocked the way before, are turned off now.

The fix

Again, ideally this part of the level must be remade, but since it's too late we can think of other solutions. I think the decent solution would be to introduce two details:

  1. Add another set of electric charges close to the location of the lever, ideally in the player's field of view when they pull the lever.
  2. Partially turn off some lights on the way back. That also will make changes to the environment and make the backtracking less boring.

Maybe it's something that we'll do in the next update.

Example: the gates in the crane area

Button to open the gates

The problem

When pressing a button the player can't see the result of their action directly. The gates must be clearly visible from this point.

The fix

A fair fix requires rebuilding the part of the level. As a fast and cheap solution we've added a shock trooper behind the gates in version 1.1, so when the player is out of the building, the shock trooper will start to shoot and attract the player's attention. We use the same trick in a few other places as an "invitation" for a player.

Example: the lever in the medical labs

Lever in medica labs

The problem

Just like before, the player pulls a lever and doesn't witness the result, which is doors opening in the other part of the level. But in this case the problem is worsened by the fact that the player might have not even seen the doors until the moment they find the lever. This case illustrates another recurring problem in Field Intensity.

Violation of the rule "A problem comes before solution"

Another rule of level-design states that the problem must be introduced to the player first and the solution is presented later (or at least at the same time). E.g. the player must see a card-reader first and then search for an access key. Often in Field Intensity the order appears reversed to a player due to the "branched" nature of the levels.

Example: key card in the rails area

Branched level

The problem

The straight path leads a player to finding a key card. However if they didn't fully explore the area before, the player might not notice the card-reader.

The fix

In this particular case the possible fix could be changing the default route of the train. This should increase a chance that player sees a card-reader before going for a key card. An extra option would be to show some scripting scene in the card-reader room to attract player's attention even more.

Currently in the mod the player hears the monster's spawn upon picking up the key card and they may use a vent as a shortcut. Spawning monsters is a cheap solution, but it can work as it gives a player an impression that they do everything right.

Problematic key cards on other levels


The problem

Essentially the same problem as in the previous example. Card-readers are poorly notable or may be skipped by a player before finding a key card. I'm actually surprised how many key cards there are in Field Intensity.

The fix

Again, we need to attract the player's attention to the card-readers somehow. I have some ideas in mind, like simply putting a corpse close to the card-reader, but as an exercise I suggest that you think of other solutions.

About key cards in general

A key card is not a standardized concept in Half-Life games. Neither Half-Life nor its expansions used key cards. Half-Life has an unused security card model in its resources and it makes a lot of modders use this item on their maps. However everyone does it a bit differently and the best practice is lacking. Some show a text in the center of the screen, some display a HUD update. Field Intensity does not show a text upon picking up the security card as we considered it somewhat tasteless, but it plays a sound and temporarily shows a HUD sprite and the card also stays in the inventory. It's still not enough as some players don't even recognize they picked up a card and they don't check the inventory.

I'm thinking of a few possible ways to improve the situation:

  1. A possible fix is to make the player "use" the security card in order to pick it up. This makes the player action explicit, but contradicts with common mechanics of the game as all other items are picked up automatically upon touching. I guess one can make an exception for quest items though.
  2. Display the key card in HUD permanently (as long as needed), instead of temporarily. The sprite can be shown in one of the screen corners.
  3. Make the security model more notable. The light blue color is too bland. The important items can be marked with some more flashy contrast colors, like red.
  4. Play an HEV announcement like "Access key is obtained". This of course is not an option for mods where the player does not have an HEV suit (like Field Intensity). Also this solution requires recording a new voice-line.

You might have other ideas and I would be glad to hear them.


Final pieces of advice for mod-makers:

  1. Plan your levels carefully taking into account the intended player's path on the level. If you feel like a change in the level plan is needed, better make it earlier than later.
  2. Have multiple testers. The more testers mean more different feedback. And feedback is much more than just bug reporting. Ask them what caused the most confusion. The way how the tester plays your maps may differ a lot from what you expect. Something that is obvious to you as an author can be completely overlooked by a player who sees the map for the first time. A bug that is not game-breaking, can be perceived by a tester as an intended event. The best way is to ask to record a video or make a live-stream. It's easy to set up a live-stream now with software like Discord which does not even require any configuration. Even better if a tester has a mic and speaks everything they think. This way you'll know how the player's mind works during the playthrough.

I hope you enjoyed the reading. There will be more articles.


That's interesting but I may not agree, you may be too harsh on yourself.

For example, I don't think it is really that important to "see" what you have "done", sometimes just a noise is enough to make you know that something happened when you pushed a button, and besides, it promotes random exploration, I think it's part of the pleasure than just being too much interventionist, or just go from A -----> to B.

I know my vision as a "player" is different than your view as a "developer", but after playing hundred of mods in the last two decades, I've seen everything in terms of "path" or "level guidance" and you're already in the top, it's not like what I've seen on mods I won't say their name, which I appreciate tough, where you wander around 10 hours not having a f*** clue about where to go or what to do.

About the key cards, that's not the first time I've seen this, but this is more seen on Source/HL2 mods indeed...

About the scanners, IMHO I've seen them well, they had a blinking red light, whereas the key cards were more difficult to see, they should have something that shines or sparkles on them to really not miss them... Because I remember clearly wandering several minutes on one of the early chapters, because of that, maybe during Gamma Labs.

But overall, really, there was no real big "flaws".

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FreeSlave Author

Thank you for you comment.
Adding a blinking light in addition to the glow is a good touch actually.
I don't think that existence of the mods that are full of level-design mistakes justify problems presented in Field Intensity. As they say, always strive for the best.
Also the sound is pretty important too but I would say it acts as an additional hint to the visual one in this case, not as a replacement. After all, there're people who can't rely on sound. For example, you played the mod with low sound volume because of your family duties. There're also people with a hearing impairment. So the best option is to have both visual and audial hints.

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I want to add a few more:

- the unbreakable glass in the first image is iirc a dev texture for said texture. it's there in a few other places across the mod.

- generally odd texturing choices for grills on doors and walls. very apparent at Black Mesa Times.

- glass lighting in dark areas in general is buggy. zhlt_embedlightmap should be used for all the glasses throughout the mod. see:

- in places where a bunch of fire sprites are placed together, they have the exact same scale and sometimes the same framerate, which is uncanny.

- the same thing with the flags in the intro, so much so that I released my own patch that replaced the flags and set them each on slightly different framerates.

- a few instances where the node mesh are disconnected, causing NPCs to fail to navigate to you when they're out of LOS.

- in Deathmatch, the hole in the blown-up door is way too small to make the escape from the voltigores easy.

A particularly bad one is that the black ops osprey fight near the end is way too difficult. the arena is very poorly lit, and visibility of the black-clad npcs against dark areas is abysmal. there's also not enough cover. And the fact that the osprey will continuously drop more npcs just aggravate things; in HL at least you have the option to dash straight through to the bunker and go down the ladder.

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