Usually the starting point is pretty similar as well: the player has to get from A to B, or fight enemy X, or has free reign to explore with several points of interest. Whatever the game genre, there's always going to be a starting point in designing a game level which is objective-driven, with the gameplay arising out of how the level facilitates and mediates the player's pursuit of those objectives.
However, while oftentimes you might have that clear start point and at least some idea of an end result in mind, usually getting to that end is a lengthy and sometimes painful process, as work is done, redone, moved about, and completely deleted as the needs of gameplay, story, and art direction change. While there is no surefire way to end up with a great game level right from the start, I've discovered a number of ideas to keep in mind that can greatly speed the level creation process and ensure that less work needs to be done in the long run.
Accentuate the Core Characteristics
Subtlety, though something to strive for, often doesn't work so well in level design, especially in action-oriented games. Similarly, realism is also great, but sometimes being too realistic can also lead to a feeling of blandness (just look out the window sometime). It's the high-impact, distinctive locations that stick with us even after we've turned the game off, and that take us away from the real world and into fantasy.
To that end, it's important, right off the bat, to identify exactly what sort of core traits and characteristics of a level are important, then play to them, and turn them into strengths. Is an environment sprawling and flat, with rolling plains and dusty roads? Are there towering cliffs and deep valleys? Is it a futuristic, alien space station with lots of curves and loops? Not all levels are going to be completely unique or interesting (a small shop in an RPG, for instance), but it's always good to have something to latch onto as a starting point.
|Skyrim's vistas border on the geographically absurd, but they're what give the game so much character.|
Mood Through Design
Though music and sound, artistic direction and lighting can all have a big influence on the player's perception of a game level, the level design itself is often extremely important in nailing the intended mood and feel. This is one of those more subjective points, but I think it's worth bearing in mind that often the core geometry of a game level is just as important in establishing the mood of a given game level.
One of the best examples of this I've come across recently is Deus Ex: Human Revolution. The hub area of Lower Hengsha isn't just great-looking, it's also a phenomenally well-designed location. The intent is clear: a city area that feels bustling and crowded, as well as foreign and unfamiliar. By transforming what could otherwise be a fairly straightforward location into a multi-story urban jungle, complete with rooftops, streets and sewer canals, Eidos don't just make a more interesting level, they also make one that directly improves the atmosphere and feel of the location in such a way that is almost integral to it; doing the same for the game's Detroit hub just wouldn't have been right. The design is so successful that you could actually take out most of the distinctive artistic features, and you'd still be left with a level that stands out.
|Human Revolution's busy, multi-level environments help establish mood beyond what the graphics themselves are able to provide.|
Always Keep the Player Engaged
There is nothing worse in level design to see the player running in a straight line from A to B, with little to no maneuvering required in between. Though it may be realistic to provide a path that's completely straightforward (real-life city streets rarely resemble mazes), from a gameplay standpoint, it's usually completely and utterly boring. Playing a game is all about being engaged and wrapped up in an experience, so the more you give the player to do, the better. In most games, the simple act of getting from one point to another isn't too interesting, but the more you can do to make that act fun, the better. The player needs to feel he or she is actually doing something, even if from a purely functional perspective, there's no difference.
To use an analogy, it's a bit like an animated loading screen, or the mouse cursor changing to an hourglass on a computer when you're opening a program: unless the user/player can see something is actually happening, and there is clear and obvious feedback for his or her own actions, then chances are he or she is simply going to think nothing much is happening at all. Your goal as a level designer is to avoid that feeling of nothing happening as much as you possibly can.
|Left 4 Dead 2 never, ever gives the player a straight line to follow - even a few cars to jump on or climb over make a world of difference.|
If there is one simple trick to making a level more interesting, it's this: stop thinking in two dimensions! Most game SDKs by default will start out with a completely flat plane to work with. Though it's easy to think "well, sure, have to start somewhere," it is surprising just how much of an impact these flat, featureless planes can have on your game levels. Flat, is, by definition, boring, and the closer your game level is to flat, chances are it's going to be less and less interesting to play. Once again, an appeal to realism is tempting (of course we don't have constant drastic changes in elevation, it's impractical), but even in "realistic" games, the hyperreal is what rules, not the real.
Creating a level with verticality in mind right from the start can be an interesting and entertaining approach. Usually, I don't do it, and those I've spoke to also tend not to think of it so much until after the fact. After all, that's kind of how we think about level design on a basic level, from a top-down perspective - especially those who have a background in isometric games, or even tabletop games. When we plan out a level, usually it's also in two dimensions rather than three, and without turning a conscious eye towards that, sometimes it's possible to build a game level and suddenly find, "hey, wait, this is a lot less interesting than it seemed on paper!"
|Consider just how much more interesting Batman: Arkham Asylum becomes simply by placing enemies and objectives on multiple levels, or requiring traversal and gliding to get from place to place.|
Composition & Artistic Principles
Though level design in and of itself isn't always directly connected to art, it's important enough to think about how a level will look from a compositional perspective even in the early stages when you're just sketching out a layout. You don't have to be an artist to do this, either - there's just a few basic rules to keep in mind that can make a huge difference in speeding along the level design process, and that will provide good-looking levels without waiting for detailing and lighting to get involved.
The most obvious and essential of these is, at least in my opinion, the rule of thirds. Though levels take place in 3D space, often it's easy to anticipate where the player is going to be looking at a given time - whether that's when exiting a commonly-visited location, walking a familiar road, or moving towards an objective in a linear fashion. As such, it's important to drop the camera to ground level and figure out what the player will be looking at. Building a level around the rule of thirds is an excellent way to provide visual interest and to make sure that each portion of the game world is adequately filled with something.
|Always consider how compositional techniques like the rule of thirds can complement a level's aesthetic - BioShock in particular makes extensive use of it.|
Of course, the most important thing to note about this section is that none of this is set in stone. The rule of thirds and other artistic principles are all well and good, but they shouldn't be used everywhere, especially where inappropriate to achieving a certain narrative goal. For instance, Half-Life 2's slow progression towards the Citadel wouldn't be nearly as effective if it wasn't literally looming over the player, and sometimes too much symmetry, or too many colours that fit together just right can become formulaic.
Level design is a slow and steady process, but it doesn't have to be extremely lengthy and difficult as well. Between teething pains working with tools, waiting for the right art assets to become available, and other production pipeline concerns, it can sometimes feel as if your work is never done. And while it's true that you can always tweak and play with something forever, by keeping in mind some of the points I've made above, you'll spend less time on redesigning and rebuilding your levels, and more time focusing on the details and particularities.
As usual, I've only scratched the surface of this topic, and would love to hear any more "quick tips" or fundamentals that anyone else has to share. Please feel free to comment and leave any others you might have picked up yourself!