Background
I've been playing LoL for a short while. I started with blindly following guides and slowly moved towards adapting my items and abilities to the situation. I still haven't experimented with runes and I don't know if I actually should, at least not at this point. I just watched a 3-hours long guide explaining all the runes and their uses and it really got my imagination running. There are so many rune builds I'd want to try with so many champions now that I understand what they do!
When I play, I want to have fun more than anything and I really like the satisfaction of making something unorthodox work. At the same time I don't want to be the reason why my team lost. It's fun to go 1-7 with a troll Magic: the Gathering deck, because winning against the all odds matters more to me than actually succeeding. But in a team game like LoL, winning consistently should be something I'm at least trying to do.
Problem
However when I check stats on mobafire or mobalitics, it seems that best runes for every champion have been already solved. Top 3 builds with highest win rate usually have very little difference between them. Different guides show very different rune build, but successful Bard always take specific Resolve/Domination runes and every successful Garen will take Precision/Resolve with only variation being which resolve rune should be taken, etc.
I understand that most of those runes were most likely discovered by experimentation and that, although unlikely, there might be an undiscovered set of runes that is even better than what is currently at the top. But I still don't know enough about this game to understand why I won or lost. Did I play really well, did my opponent play well, did my team make macro mistakes, did I or someone else buy wrong items or did I pick the wrong rune? I notice my skill shots getting better and abilities making more impact on the game as I get more experience with a champion but other than this simple feedback, I don't think I could tell a difference between being behind because of bad runes and being behind because of any other reason. And if the best runes are already known, I feel most of the times I'd just be making my champion weaker and hurt my team by diverting from them.
Question
Keeping all the above in mind, how much would I be hurting my team by choosing suboptimal runes I feel might work with a champion instead of those recommended by meta trackers? Is there any value in experimenting with runes and trying to adapt them to my play style or should I adopt my playstyle to the runes that are currently the best?
Best Answer
Apart from some runes which plain have no discernible effect for certain champion, most runes combos work - and just for the sake of learning how the runes look like and work there is some sense in at least having tried each rune a few times.
Beyond that, it boils down to how much better you want to become at your play style.
Because below a certain level of high-performance play which most players never touch, the runes have a much greater psychological effect than actual gameplay impact. If you deviate from things commonly understood to be effective in your Elo bracket, then just the fact that your teammates and enemies notice this deviation will hurt the rate at which you are winning games because of how attitude and focus have such giant impact in the majority of skill brackets.
If you still wanted to win the majority of your games, you would have to be better at what you are doing than the majority of players are at what they are doing. Thus it's generally much easier to stick to things most people expect to reliably work well (in League, generally called Meta). Delivering average performance with uncommon choices was a 5 percent point difference in win rate for me when compared to average performance with common choices. That is roughly what you would have to make up for. If there was a rune combo that had this much win rate difference for more than some specializes players, it would be considered "broken" and swiftly balanced away.
Since you generally learn the game better while you are playing close games (as opposed to a series of stomps), I highly recommend not trying to adapt too early - instead first trying to becomes reasonably good at things you will find in popular guides.
But if you already notice you tend to micro-optimize one particular champion and/or strategy where you quickly become much better than the average player, then trying out your own build & runes in that niche where you have a clear advantage and enough specific knowledge to actually utilize the minute differences between runes makes more sense.