Level Design – The Decision Tree

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Level Design – The Decision Tree

The main mechanic in Anomaly 1729 is world rotation. It’s not completely freeform, however. We limit the ability in a number of ways in order to create interesting puzzles and situations. Because the goal is simply progression based, to get the room in the correct orientation and get through the exit door, these limitations keep the player from immediately putting the room in the right spot and skipping large portions of the level/puzzle.

This is primarily done through the rotation cubes. Each cube rotates the world on one axis, and you must shoot the cubes to activate them. The cubes are small, are sometimes behind barriers or walls, and are often initially out of reach of the player, as the Transformation Gun’s projectiles shots have a limited range. This allows us to control when and where the player can rotate the room, meaning we can design puzzles that have progressive steps to solve them, which is an important part of puzzle design to me. As a player, you should be able to see your goal from the start, as well your first step to accomplish that goal. It should only be the intermediate steps that are obscured. So, for example, you may see the exit door when you enter the room, and see that it’s off on the x-axis. You know you need a purple cube but may not see it or can reach it. But you should see the first step to start you toward that cube. Anyway, my view on puzzle design is for another blog. My point is that by limiting when and where the player can rotate the world, we can better control the pacing of a level and the choices the player can make in it.

Whenever the player is in a position to shoot a rotation cube, we call this a decision point. The player can rotate the room in one of two directions, depending if the blue or orange shot is used. And they always have that choice. It’s important to us that the player can always rotate the world counterclockwise or clockwise because it makes the game feel more open, like players are in control of the world, even though they are limited to one axis at a time.


So there are two outcomes, for the most part, at each decision point. And we try to make sure the player can always see the outcome of that decision before it’s made. It should be evident where the room, and the objects within it, is going to end up after a rotation. The player should never be blindsided by a random death wall that wasn’t in view before the rotation. Again, this is done to make players feel in control of their surroundings. And we tried to make each decision point a divergent path. Sometimes there are dead ends on one rotation, or geometry that will push the player to another part of the level, and sometimes only death awaits a wrong decision. But for the most part these decision points are paths the player can choose to go down.

However having all these divergent paths can make level design a challenge. In a room with one or two rotation cubes there are a small number of possibilities. But as the levels get more open and the number of rotation cubes increases the decision tree becomes more and more complex, to the point that it’s almost impossible to track the number of paths the player can go down. This is an ongoing level design challenge. The levels go through a huge amount of iteration, as we’re continuously looking for strange puzzle solutions and places the player can get stuck. And I’ve come to terms with the fact that not all those holes will be found, which is ok…I think. The alternative is making the levels so linear and tight that it feels like the player has no choice, is not in control of the environment. At the same time, finding these areas can break immersion, because it’s immediately obvious that this area was something overlooked by the level designer.

I think it’s about finding that perfect balance. I don’t want to shy away from making levels that are crazy and complex and mind-bending because that’s where the rotation mechanic really shines, it’s the heart of the game. We just have a lot of playtesting in our future.

Thanks for reading.