It's much less than 75%—but then, you only get the engine, you don't also get the multimillion dollar award winning game to build on top of. If you make a mod for Skyrim—say, a new dungeon—you're adding that to the existing game and assets and dungeons and all that. You don't have to build everything from scratch, and you don't need your new content to be enough by itself to get people to buy it. A game with 1 dungeon, who would buy? But a mod that adds 1 dungeon to Skyrim, sure.

So yes, 75% is high, but the conversation should be, what cut should everyone receive, not, why does Bethesda deserve a cut at all, which most of the conversation actually is.