Machinima is the art of using someone else's rendering engine to portray a story different from the original intent. Machinima is the practice of live-action filmmaking within a 3D virtual space. However, do to accessibility, it mostly defaults to existing game engines and their associated IP. This will change as more sandbox-theme virtual 3D space is developed.
Moe Napoli writes "Just learned over at the Thinking Machinima blog, that Microsoft has released "content usage rules" that allow the end user to create machinima with a certain set of their titles, including the Halo franchise and ShadowRun (but also Age of Empires!). This is a fairly large step into the allowance of user-generated content, but the rules are extremely limiting — the terms keep people from creating anything that extends the property's universe. Question is, isn't that the reason people make machinima in the first place?"