6th-level · Illusion · Ritual
Casting Time 1 hour
Range 150 feet
Components V, S, M (a drop of blood smeared on a silver rod worth 100 gp)
Duration 12 hours
Classes Cleric, Sorcerer, Warlock, Wizard
You cause menacing shadows to invade an area 200 feet on a side and 50 feet high, centered on a point within range. Illumination in the area drops one step (from bright light to dim, or from dim light to darkness). Any spell that creates light in the area that is cast using a lower-level spell slot than was used to cast encroaching shadows is dispelled, and a spell that creates light doesn’t function in the area if that spell is cast using a spell slot of 5th level or lower. Nonmagical effects can’t increase the level of illumination in the affected area.
A spell that creates darkness or shadow takes effect in the area as if the spell slot expended was one level higher than the spell slot actually used.
When you cast this spell using a spell slot of 7th level or higher, the effect lasts for an additional 12 hours for each slot level above 6th. ***Ritual Focus.*** If you expend your ritual focus, the spell’s duration increases by 12 hours, and it cannot be dispelled by a spell that creates light, even if that spell is cast using a higher-level spell slot.
Source: Deep Magic 5e · OGL/Open