@Haelwenn /элвэн/ :triskell: @nprofile1q... you can explain the rules through world building, dialogue or examples, without resorting to page long details.

It depends a little bit on how much your protagonist can know from it's POV and how much you can assume with the reader.

I think you don't need to explain someone that when you hit the light switch, the light will turn on, but if you assume everyone knows how an electric curcuit works, you might lose some people.

They learned it way back in school but if they never used that knowledge, they will not understands what happening there. Of yourse they will be able to tell you about voltages and currents, but from my own experience for a lot more people than i am cormfortable to accept "Electrics" is just another magic thing. "TV", "phone" and "internet" are just more complex layers on top of it.

My point here is that building too much on readers knowledge can backfire really hard.