Making a game engine with Unity engine? Legal?

Hello, so I was planning on buying Unity Pro and making a horror game engine using the Unity3D engine (This will work by using the ‘engine’ to create levels which will be saved as files then added to a separate unity build standalone). I was wondering if this was legal, also; would users be allowed to sell they’re created games from the engine I’m planning to build within Unity Pro? Thanks!

Answer: “After contacting both unity support and the sales team the short answer is ‘Yes’, it is legal. :)”

~Sean

Yes most of it is legal the only thing you cant do is allow users to sell their games.