Similar to the fae affliction of iron, the progeny of Dream cannot abide the touch of salt, and will recoil from it. Although diluted salts such as what is found in sweat (for example) are no more harmful to dreams than the iron in blood is to Faerie creatures, even a handful of pure grains can be effective. By making a line of salt and chanting the proper minor wards to bind it in place, a magician may create a barrier which dream-creatures will not cross. The amount of salt required increases with the length of the line, naturally, and the line cannot have any appreciable gaps or the ward-song cannot draw on its power for the intended length.
If drawn in a circle, the barrier creates a space which dream-creatures will not enter or leave. If any sentient being that can dream crosses the barrier it will break, rendering as useless as a line of sand. Sleeping within an enclosed Dream Ward will prevent anyone inside from dreaming.
The base difficulty to create a Dream Ward is d6, and maintaining it costs its creator a point of strain each half-day (starting at the moment of creation) that cannot be recovered from until the next full sleep after the Ward is broken. Similarly, anyone sleeping inside an enclosed Ward gains a point of strain each night; these cannot be recovered until they have a full proper sleep during which they are allowed to dream. These costs are cumulative if a Ward’s creator sleeps inside it.