Combat Skill - Remove the luck factor

So.. I was playing a few other (non-MMO) games, and it kind of dawned on me that to have any real "skill" in combat it should be based on set values.

Most MMOs factor in luck with abilities like "Deals 1 to 250 fire dmg" or glancing/critical hits. 

The combat needs to have a certain degree of predictability to allow the player to use his "skill". It could also be more "Action-based" -  things like line-of-sight and no "lock on target" do enhance what i am talking about as they force the player to move, making each fight different. What should make fights unique is what the PLAYER does and how the game reacts to it, rather then what some random number generator in the games code decides.

Making the combat rely on set values gives the player much more control over their character and allows the game developers to make much more challenging fights because a player can't fail it trough a fault not of their own ( there would be no "Aww.. the boss killed me because i glanced the whole time."  ).

Lets be clear though:

I am not saying that we should remove critical hits, damage mitigation and a myriad of other effects, but that we should give control over them to the player. Have abilities that build up and then make your next hit critical, or perhaps make fighting with a certain style from certain places give you a set critical buff - eg: "Stand in the blue flames to make every second hit a critical, and every other a glancing blow". Perhaps - cliche - add backstabs for rogues.

People should be able to trigger abilties at will, provided they have enough of reources and don't have them on cooldown, which would mean they have to react to what the enemy does. In a similar manner, the emenies could be programmed to react to what the player does. Combat should be situational but not based on "luck". 

--------- CLIFF ----------

Down with the Random Number Generators! Power to the people! Let us decide about our own fights!