Hungry Plains

You move or you die. This is the mantra of the Hungry Plains. Cities lumber across the sea of grass, always on the move to avoid the devouring plants at their feet.   Two hundred years ago, this world was at the height of a magical age. A threat arose, someone who bent the world's magic to his will and united the scattered evils as one terrible force. A group of plucky adventurers, just starting out on their hero's journey, came together and led a resistance.   In the final battle, they failed.   Backlash from the partially-completed ritual corrupted magic all across the world. Taking on an almost physical form, magical particulate settled in plants. Now, when enough magical energy is present, the plants become mobile and carnivorous. Like magnetic filings, magic attracts more magic, and the collected energy corrupts and mutates what it touches. For the people of the world, the only true defense to to stay on the move. To keep ahead of the ravenous plants, they build their dwellings on mobile platforms. Animated statues, clockwork engines, and gigantic beasts all serve as cities for the remnants of humanity.