The definition of this cube is relatively simple: it is a cube composed of cards from my collection. There are a few rules, which aren't as firm as they used to be.

1. No proxies. This includes no proxying cards that I own that are in use in other parts of my magic collection. I normally do this for commander staples. This is the rule that is most likely to be abolished in future versions of this cube, but stays for now.
2. No buying cards specifically for the cube. Cards must already be in my collection or obtained through purchases of product I was already going to get. This makes limited events and disassembled precons the main form of introducing new cards to the environment. (Note: This rule was broken during construction. My selection of available dual lands was severely lacking, so I got a few common duals from DMU and MH2 to fill things out. Yes, this was actually a marked improvement from what else I had available.)
3. No taking cards out of existing decks. This rule enforces that cards must come from the "bulk" part of my collection, see the below section on goals for more information. (Note: This rule was also broken during construction. I couldn't just have 9 signets, dude.)
   Why?
   Well, the inception of the cube came from a conversation with my wife. I was describing an idea for a commander deck I wanted to build and she asked if there was something I could do with the boxes of bulk I own. (Note: My collection is not terribly large, as I've been playing for less than a decade and don't make nearly as many purchases as I used to.) This question led me to think of what would be a project that would use as many pieces from my collection as possible. A large cube seemed like a pretty easy answer, but the implications were actually really interesting to me. By limiting myself to my existing collection, the cube building process would have a sort of limited-style restriction of its own.
   So a primary goal of this cube is to cut as much into my collection as possible, thus informing some of the above restrictions. These rules are likely to shift going forward, but I felt it was a good starting place.