But then you've got stuff like Skywind, who are painstakingly recreating Morrowind from scratch in the Skyrim world builder, from terrain to new 3d models to mu

But then you've got stuff like Skywind, who are painstakingly recreating Morrowind from scratch in the Skyrim world builder, from terrain to new 3d models to music... Individually, building one thing from scratch should be clear from a copyright perspective. Trying to port the whole game from scratch though (rather than an end-user datafile conversion tool) feels like it's destined to failure.