I recently wanted to make a research mod myself, due to the fact that I felt most of them were sort of lacking the spacing and neatness. Adding too many things way too fast, and not even making any sense in which you could learn based on previous things you could learn. From most of the /just/ research mods, at least. I believe I found a way to make it so it does that. I’m not a coder, and I’m using the UME… And I’ve come across an issue. I don’t know how to add engine collision to two things? Say for instance, I have SD and HD. HD is learned after getting higher graphics and learning SD, it’s an upgrade. But if you have an engine with both, they can both be selected on the Graphics phase of game creation. How do I make them not work together?