I know that MOC means "my own creation" as noted here. What I would like to know is do you call the actual act of creating a MOC, "MOC building", or is there another official term? I wanted to build with my son and called it 'free building' as I did not know any official term, and only just learned the acronym MOC. I would like to know how to properly say, "Let's go ___________" (build without a plan).
edit: I think where I was confused came from the fact that I've read here and other places that using the term LEGOs is incorrect, that you are supposed to use LEGO bricks and I found that awkward to say so I thought maybe there was also a special term for building official sets versus building a MOC.