Let me try to tell you in the most technical way that this game is not "balanced". I won't flame about some unfairness or op champions or what so ever to get tons of downvotes. I will just tell you that you should not call this game balanced because most of you don't really think of the meaning of balance and I hope after you read this you will call it something else because calling it balanced is completly wrong.
First of all, let us look up what **balance** means by definition:
1. An even distribution of weight enabling someone or something to remain upright and stead.
2. A condition in which different elements are equal or in the correct proportions.
3. A state of equilibrium or equipoise; equal distribution of weight, amount, etc.
4. A state in which different things occur in equal or proper amounts or have an equal or proper amount of importance.
So for those definitions it is easy to see that 2 different things have to have similarities to even can be compared. These 2 different things compared to each other have to be the same in some ways to be called **balanced** e.g. as much damage/life/stuns (times)/slows/etc.
The mathematical way is easy:
A = B --> balanced
A > B --> **not balanced**
You can adapt this to the League of Legends system by simply googling the counter champion of each champion:
Ryze counters Ahri --> **they are not balanced** because the one is stronger (better abilities, stats, etc.) than the other.
So you still think LoL is **balanced**? Then I don't understand how your brain works. But you could say that the overall game in the whole is balanced. In summary it may be, but what does this mean?
It simply means that you don't win by your skill, you rather win by your champion. If you picked a counter champion of your opponent you will win. Is this the meaning of this game? In the most other games like CoD, BF, CS, etc. you play a character with weapons and those weapons have very similar properties (damage/range/reloading) so those games are more likely to be balanced (if you can better aim or faster react, you win). Okay but those games also have many different weapons? Yes but there are only 3-5 categories (Assault Rifles, Shotguns, LMG, etc.) so the developers only have 5 different kinds of weapons because there are nearly no differences inside a category which measn they have 5 things to be in balance to each other (mathematically there are 5! = 5*4*3*2*1 = 120 connections between all categories, this is called a complex system which means the change of one category can affect the 4 other categories and there you go trying to fix the other categories so they are all in balance again but then by fixing the next category you may affect the 3 left categories and the previously changed one too so you .... bla bla bla).
Do you understand me now?
And now think of 120+ different champions in this game. If you fix one you may break his balance and he gets up/op (see this raging community after each patch).
The human race trys to control complex systems since the discovery of the nuclear fission, results are Tchernobly or Fukushima to only mention the most popular.
I hope you now know what balance means and I hope you will never ever call this game balanced again, otherwise you should see a doctor and check your brain.
**PS: you win by your champion, not your skill!**