The other day, as I was writing up the list of campaigns I've played, it occurred to me that I've had a shift in my thinking about campaigns over the past seven-odd years I've been gaming. With all the games I'm thinking about running now, I consider the system first, and then think about what I'd actually run with it. When I came up with my first couple of games, that order was reversed: concept first, then a system to match. I don't think this is a good trend.
There's a certain degree of inevitability to the shift. I know about a lot more systems than I did when I first started playing, I own a lot more systems, and I have a lot more interest in trying systems just to see what they're like. Back in the day, I couldn't think up a campaign system-first, because while I knew there were other systems out there, I didn't have any idea what they were like. I pretty much had to come up with a concept, and then go looking for a system.
But still, I don't like it, especially since my last few campaigns have been a bit thin in the concept department. They picked up more character over time -- Traveller got a big ol' burst of concept during character creation, and Is This Fair ended up with some honest-to-Gygax nuance in the end -- but the danger there is that they get defined by the loudest player's character. Next time around, I want to see if I can make the setting and concept itself a bit more vivid.