Structure is a funny thing. In my mind’s eye, when I think of “structure” I think of buildings whether I mean structure in an architectural way, an algebraic/mathematical way, or a game mechanics way. A sprawling structure is something like The Winchester House – rooms and corridors going in all directions, linking to each other in innumerable ways. Those with a mathematical background might want to think of the tree of elements of the free group on a few elements.
Structures collapse when bits of the structure coincide with other bits (quite literally when a building collapses!) In algebra we collapse structures by saying a bunch of things that we previously considered separate are the same thing. Recently I’ve experienced a bit of game mechanic structures collapsing and thought it might be interesting to explore. Don’t worry, I won’t bring up any more architecture or algebra.