mechanics make conversation

"You know the grand unified mechanic? You know the thing where you always roll percentile dice under the skill? Right? That's a bad idea, turns out. That's one conversation we can have, right? The conversation where I say, "Do you succeed at driving the car?" and you roll the dice and say, "Yes." That's a conversation we can have, but that isn't a very interesting conversation. That isn't a conversation that is always interesting for every circumstance.

'Do you hit him with your gun?' 'Yes.' The conversations we can have when we're playing a game are much more various than the single die roll. For instance, you can say to me [referring to Murderous Ghosts], 'What do you hope the ghost doesn't do?' and that's a very different conversation than "Do you successfully drive the car?'"

-Vincent Baker in his Ropecon 2013 session entitled, "How to Design an Roleplaying Game that Doesn't Suck"