For those of you who haven't played with it, here's a basic rundown of how the system works in other games.
There are 3 "main" stats, and 3 corresponding types of hero/champion to each stat.
* Used primarily by tanks. Points of this stat grant Health.
* Used primarily by Auto Attack based carries. Points of this stat grant attack speed.
* In Dota, this also grants a considerable amount of armor once you've stacked up a bunch of it, mostly so that carries can stand up to other carries.
* Used primarily by casters. Points of this stat grant Mana .
* Mana isn't so much an issue in League, so maybe AP would make more sense.
There are exceptions to the rule, of course. There are several casters who are STR/AGI, there are a few carries in the STR/INT categories, and there are a couple tanks sprinkled into the INT/AGI categories (though in this last category there aren't nearly as many as the others).
For some examples...
* Aatrox, Darius, and Maokai would be typical Strength characters.
* Urgot, Thresh, and Graves would be Atypical Strength characters.
* Yi, Caitlyn, and Vayne would be typical Agility characters.
* Fizz, Akali, and Elise would be Atypical Agility characters.
* Veigar, Vel'koz, and
If a champion/hero gains a point of their corresponding stat they will (in addition to the main bonus) gain a point of base attack damage, plus some extra stats.
Got it? Cool.
1. It cuts down on item abuse. Say Fizz was made into an AGI champion. While he'd continue to benefit from AP builds and carry builds, he'd probably stop abusing tanks items unless they had a specific desired effect.
2. It brings new builds for Sheen users, since this means you can increase your base AD by building your primary attribute.
3. It brings a new avenue for tankbusters. % Max HP damage is the same no matter who you fight, meaning it can still be stronger than intended against squishies. On the other hand, Dota has mechanics revolved around reducing a units primary stat, which make them potent damage tools against frontliners without having any effect on the HP pools of casters and carries.
4. It gives tanks naturally powerful basic attacks without giving them special bonus damage. Morde wouldn't need bonus magic damage on-hit, his AA's would just hurt a lot naturally. I don't even think this would give rise to an egregious tank meta, since buying Strength doesn't give attack speed, meaning their DPS isn't too high. Some champions would need adjustments (Maokai shouldn't have one of the highest base attack speeds in the game if we're going to make his individual punches strong) but a world where Sion doesn't need to build full AD to make his Axe hurt sounds good to me.
5. It makes it easier to make Bruiser carries. Imagine if Draven were a ranged STR carry. High burst, pretty durable to magic, but low armor due to low AGI.
6. It makes it easy for anti-carry niches to be carved out. Say you make Lethality into a stat that only pierces base armor (ie Armor from base stats and attributes). That would mean you aren't amazing at dealing with tanks and mages who might buy a bit of bonus armor... but you're incredible at dealing with Agility carries, who derive most of their durability from the armor they get from Agility.
There are probably more reasons I could think of