I was tasked with creating a "prison cell" that could be placed in two of our battle royal biomes. Thinking towards the future and wanting to make this feature as low scope as possible, I wanted to keep their placement small and reusable in a way that art didn't need to make any significant edits to the surrounding area for wherever these prison cells were placed.
Even a simple portal cube (400x400) can take a large amount of floor area, so I was certain I couldn't go larger than that on the XY dimensions. However, with this goal in mind I couldn't possibly provide players with any compelling or novel experience. In addition, I've always thought it's important to reinforce the larger theme of the game whenever you can in the features you design.
Coincidentally, we had level portals, which were built specifically for bridging players between the biomes in battle royal - but now I could re-use these teleporters that you can see through as a medium to take players to a large space "inside" my cube, essentially a Dr. Who TARDIS. This was a really exciting discovery because it meant my prison cells could be any size and in any configuration I wanted, with some limitations (ie building them under the landscapes clear of everything else and each other).
I made a number of iterations, some simple and some complex, some with two entrances and some that connected between biomes like a secret passage like a game of Clue.
Brainstorming TARDIS Ideas
Approved TARDIS versions