Building a game the way we are, prototyping the game play first, changes the order of things compared to a more traditional development method. One of those things is balance. Balance is usually one of the last things done. However, since our game is already completely playable, I get to play with different balance numbers this early in the cycle. ( Or am forced to, depending on how emotional the last play test was. 
I sincerely believe that whomever does the balance on a game has the most influence on the design of the game. They control how the game feels, the essence of the game. You can balance a game many different ways and still have it be 'balanced'. However, you'll end up with two very different games. Imagine if you played Call of Duty where the players took 5x longer to die, jumped 3x higher and ran 2x slower? What if Halo 3 was mostly 1 shot,1 kill? Or if Gears of War enemies were 3x weaker but you had 3x more of them attacking you? (I use console shooters as examples for good reason.)
Balance is to games as editing is to movies. (They give Oscars out for editing, so it is a big deal.) You can invoke different emotions in your players by altering the game balance just like you can with editing camera footage. Take the same raw materials and create different things out of it.
Now, some designers believe that you balance a game by finding some magical formula that will tell them everything they need to know. I am not a subscriber to this method. I believe in using tables to allow you to see what's going on, which is important, but lots of play testing allows you mold what's going on.
I'll give a very simple example:
You want a player with 100 hit points to die in 4 shots from an assault rifle. How much damage should that assault rifle do per shot?
25?
A formula would say 4 x 25 = 100. Dead in 4 shots. Perfect balance.
Me? 33.
Why?
What happens when a player takes 3 shots and ducks behind cover? 1/4 of your hit points has no drama. 1/4 of your hit points just says 'I'm hurt and I need to heal'. 1 hit point creates drama. 1 hit point makes you say 'Holy $%#@%! I made it out with a sliver of health!'.
That is how you change the feel of a game with balance.
This is how our game will be balanced.
And now… a picture. Historic snow in the Seattle area. My poor mini hasn't moved in days. Thank goodness for teh intArw3bz.
