During a special presentation at New Zealand GDC, a few of the members of Path of Exile gave a special talk called The Labyrinth: Building Pathways For Players. This detailed talk gave a lot of insight into how the game was made, and how the Labyrinth was set up for players, as well as the challenges they had to overcome in order to make it. They wrote down the speech, and put it into a special Google Doc. Here are some of the highlights.
First, they broke down what Path of Exile is, and how that affects building an area. Since they’re an action role playing game, one with a fixed camera and with the allowing of players to pathfind, this affects the design process. Levels are made up of several interconnected rooms. These rooms make areas, and those areas make levels.
The Labyrinth itself was a very different kind of map for Path of Exile. They wanted a place that was full of puzzles, secrets, and deadly traps. Furthermore, it was going to be randomized somewhat in regards to the layout. To help nail the look, they wanted to make sure they could visualize the traps first. So they designed spike and blade traps, arrow shooters, and lava so that they could move on to placement.
Not only that, they wanted to make The Labyrinth a puzzle dungeon, one with pressure switches, cogs, doors, and more. Some were meant to be overt (visible), while others were meant to be much more hidden.
To see the full breakdown of the level design of Path of Exile, you can head over to their Google Doc.