In this particular scenario, what power does the DM have? As far as I can tell, the DM set a challenge; the player declared an action to resolve that challenge; the DM set a condition for the player to meet; both parties agreed to abide by an independent arbiter (the dice) to resolve said challenge.
- The DM exercised his power in creating a challenge and setting the conditions to overcome said challenge.
- The Player exercised his power in choosing to engage this challenge and how.
- Both transferred their power to an independent arbiter to resolve this challenge.
The player has the power to choose to engage a challenge, how to engage the challenge, and whether to agree or disagree to a means to resolve the challenge.
Back up a second here. How can the player agree or disagree on "a means to resolve the challenge"? At what point can the player change how a challenge is resolved. It's true, I suppose, that the player can disagree, but, so what? The player disagrees. He can't do anything about it, other than walk away from the game.
I'll give you an example from a game I was playing. I had a 4e rogue with an at-will ability that let him calculate his jumps as if he had a running start, even if he was standing still. And a +11 Athletics. Essentially that means that my minimum jumping distance is 12 feet under 4e rules. We come to a 10 foot pit. I declare that I jump across the pit, sailing with ease.
The DM asked me to roll. "Why?" I asked.
"Because a 1 automatically fails skill checks," was the answer.
Now, I argued this. I disagreed because, in the rules, this isn't true. This was a house rule that the DM had added in. His response was, "It's a common house rule, make your roll."
So, what power over mechanical resolution did I have here?
So, yes, as I said MULTIPLE times in this thread, a player has power over his own character. But, that doesn't change the fact that the DM has 99% of the rest of the power in the game.
It's very pedantic to argue that power is shared when one side has virtually (almost, nearly, but not quite) all the power and the other side's choice is limited to leaving the game.
It's funny though, some people are telling me that DM's don't have authority over their game and control virtually all elements, while at exactly the same time, are telling me that DM's can veto player choices during character generation.
Isn't there a contradiction there?