Taking naps every mile may not be strictly necessary; talking to people in other areas of the Free Marches about their dreams and quality of sleep will probably do the job. But taking naps is cool, too.
Either way characters will be able to discern that the whole of the Free Marches seem affected. There aren't hard boundaries; people as far north as the southern Antivan countryside and as far south as Fereldan's northern coast might report their sleep being a little worse than normal, though not on the scale being experienced in the central Marches. Sailors coming off the Amaranthine Ocean will report bad dreams in the area
The effects also won't be uniformly distributed. Kirkwall seems harder-hit than a lot of places, for example, even though it isn't perfectly in the center of the affected geographic area.
Someone looking at the collected information and a map might be able to correctly analogize it to a river–shallower/milder on the banks, deeper/worse in the central channel, with some sinuosity and tributaries and places (like Kirkwall) where the water seems to be pooling particularly deep.
no subject
Either way characters will be able to discern that the whole of the Free Marches seem affected. There aren't hard boundaries; people as far north as the southern Antivan countryside and as far south as Fereldan's northern coast might report their sleep being a little worse than normal, though not on the scale being experienced in the central Marches. Sailors coming off the Amaranthine Ocean will report bad dreams in the area
The effects also won't be uniformly distributed. Kirkwall seems harder-hit than a lot of places, for example, even though it isn't perfectly in the center of the affected geographic area.
Someone looking at the collected information and a map might be able to correctly analogize it to a river–shallower/milder on the banks, deeper/worse in the central channel, with some sinuosity and tributaries and places (like Kirkwall) where the water seems to be pooling particularly deep.