Direct from the author:
The world of Deluge is our world, perhaps a hundred years after an event that changed it forever. Since that time, the world has been under a constant rainfall. Civilization as we know it has crumbled, slowly at first, but more rapidly as the rain destroyed those aspects of our world that we had thought most secure: our agriculture and our trade. The water level has risen, the temperature has risen, and all too rapidly to react to. And no one claims any more that this was all our fault, because we know whose fault it was. There are no ice caps, but we didn’t melt them. The world is a jungle of sorts, but we didn’t let that grow. The world is now slowly taking the shape that they prefer, and a day will come when they are ready to take possession.
And some of the people of this sodden world intend to be ready for that day.
Deluge is system-free but there will be places throughout that imply systemic choices. I’ll highlight these because if you intend to fit Deluge into your preferred system, these are the places where the work might be. Sometimes that work will be identifying analogous mechanism — your system does the same thing but uses a different term. Sometimes that work will require new mechanism and where this seems likely, I’ll try to point towards a fruitful path. Sometimes you’ll have to hack through jungle yourself for it.