Drop your camper at the campground?

I would think for plywood to work properly the edge of the plywood should make full contact with the ground or whatever the surface is. I assume the only way to level it would be to dig out the area where the wood sits. Problem is Ive been on blacktop pads that arent even level, not to mention how some areas are so hard and packed down that digging out could be a real problem. Having a support system that can be adjusted with individual jacks or something similar seems to make a lot of sense.