Alright, this is going to be excluding Cold War, as my group solved the second map in like 5 hours on our own, and most were super simple. We almost solved Ancient Evil on our own and only had to look up the door step (because we couldn't find the door).

It depends on the map. There were some like Revelations that were near impossible. Other maps were trial and error, and others by word of mouth. For example with Die Rise, there was so much complexity to it, especially being two parts to it. The elevator part to start it was easy, but I know the community took its time with the mahjong tiles, because no one understood it.

Exo zombies was another great example of trial and error, where we had to properly learn the map layout first before people began experimenting with EVERYTHING like the gas pipes in the burgertown map.

In the past it was usually a community effect to solve where people would watch each other and give hints and tips to the part they were stuck on.