When Valve released the Perpetual Testing Initiative DLC for Portal 2, they unleashed a maelstrom of possibilities for test chamber designers. Gone were the days where one needed to spend hours experimenting in Hammer just to get a simple chamber. Instead, anyone could create anything in mere minutes.

The puzzle creator isn't without its faults, though, and that's where this collection comes in. Imagine that you've got a pedestal button. The first time you press it, something is activated. You press the button again, and it activates something else. A third time, and once again the output is different. Or maybe you want to get a random effect every time you press the button. What about four different buttons, and each combination yields a different output, for a total of 15 possibilities?

Of course, Valve couldn't really program any of that into simple things like buttons, so instead, we need to build our own mechanisms. Below this description, you'll find a collection of various maps demonstrating contraptions that can do, well, virtually anything. These maps operate on three principles: functionality, reliability, and, most importantly, simplicity.

If you wish to request any mechanisms, comment, and I might just build it for you! Remember that any feedback you can give would be wonderful.