So... it's just occurred to me that skill levels don't appear to be improving anything. I can't say for sure if weapon damage or magicka costs are improving as the corresponding skill ranks improve.
Perks improve them for sure, but ranks don't appear to. Again, I can't say for sure, but it doesn't seem that way. With no perks invested, destruction spells appear to me to cost the same at rank 23 as they did at rank 15. With no perks invested, lockpicking doesn't seem to have gotten any easier with rank increases.
Like I said, this just occurred to me - it's not something I've been paying attention to until now - so I can't say for sure. Can anyone chime in on what, exactly, skill levels do for your character (aside from qualifying them for perks)?

