We’ve talked so far about stringing together challenges in a linear order. Challenge 1 is followed by challenge 2 is followed by challenge 3 and so on. There are many advantages to building a game around this structure: you can tightly control the difficulty curve, easily make sure everything is introduced in the right order and you can know where the character will begin a challenge and design all the obstacles to block that specific path. But, of course, many games benefit from giving the player more freedom in how they explore the world of the game. And you can still apply much of what you’ve learned about linear level design to non-linear level design, it just takes a bit more consideration.
It’s important to note that non-linearity is a matter of degrees. If purely linear games are on one side, and completely open-world free-roaming games are on the other, there’s plenty of room in the middle for semi-linear games, non-linear games with pockets of linearity, and games that gradually open up for you to explore them.
They key is that at some point you’re given a choice as to where to go. The choice can be very small-scale, for example an offshoot path in an otherwise linear level, or it can be large-scale, like the world of an Elder Scrolls game where you can basically go just about anywhere at any time.
In this example, we have a linear level with two challenges before you reach the end.
Now, I’ve rearranged the challenges such that you can play them in whatever order you want. Each challenge rewards you with a gem, and you need two gems to open the door to the exit. Notice that your progression through the individual challenges is still the same as in the linear level, but you now have a choice of which one you do first.
In this third example, there are now three challenges that you can do. The goal is still to collect gems that you need to open the door. However, the door still only needs two gems to open. Now you not only have a choice of what order to do the challenges in, you also can choose which two of the three challenges you’re going to do.
I will go further into various aspects of non-linear level design in the coming parts. In the next part, I’ll talk about creating implicit linear structure in non-linear levels.