I'm researching ahead of the (potentially) final battle in Curse of Strahd (as the DM)
One of the tactics the party is discussing is trapping Strahd in a wall of force, and then exposing him to the sunlight shed from the sunsword.
Per the Sunblade description
The sword’s luminous blade emits bright light in a 15-foot radius and dim light for an additional 15 feet. The light is sunlight. While the blade persists, you can use an action to expand or reduce its radius of bright and dim light by 5 feet each, to a maximum of 30 feet each or a minimum of 10 feet each.
And per the stat block for Vampires
Sunlight Hypersensitivity. The vampire takes 20 radiant damage when it starts its turn in sunlight. While in sunlight, it has disadvantage on Attack rolls and Ability Checks.
There's a great discussion on what constitutes sunlight exposure to a Vampire here (short version - if Strahd can see the Sunsword, and he's in range of its light, he's in sunlight)
But under normal circumstances, no spell can penetrate a Wall of Force (discussed here) but this is a weird grey area where this is really just (admittedly) magical light triggering a vampire's sunlight hypersensitivity.
So the sunlight isn't a spell, per se. But on the flip side, Strahd has the equivalent of total cover, but not total concealment.
So is the answer "nothing gets through a wall of force" or is the answer "The sunlight sensitivity is a pre-existing condition that's trapped inside the wall of force" or am I missing something else about concealment vs. cover.
Thanks in advance!