I want to give Clairvoyance a buff, as it is a 3rd-level spell that is a little bit underpowered in my opinion.
Here is the current text of the Clairvoyance spell (from D&D Beyond):
You create an invisible sensor within range in a location familiar to
you (a place you have visited or seen before) or in an obvious
location that is unfamiliar to you (such as behind a door, around a
corner, or in a grove of trees). The sensor remains in place for the
duration, and it can't be attacked or otherwise interacted with.When you cast the spell, you choose seeing or hearing. You can use the
chosen sense through the sensor as if you were in its space. As your
action, you can switch between seeing and hearing.A creature that can see the sensor (such as a creature benefiting from
see invisibility or truesight) sees a luminous, intangible orb about
the size of your fist.
And I would like to add the following:
While seeing or hearing through the sensor, the sensor has a move
speed of 10 feet in any direction. It cannot take actions (including
the Dash action), it cannot move through objects (even as thin as a
piece of paper), and cannot interact with its surroundings (i.e., it
cannot open doors or windows). If the sensor is moving and something
larger than 1 inch collides with it, the spell ends.
Would this change maintain Clairvoyance's 3rd-level ranking? Or would it bump it up to a 4th-level spell?
Best Answer
It would bump the spell to 4th level
By adding movement speed to the sensor you are making it quite similar to Arcane Eye, which is 4th level. Comparison of your version of Clairvoyance with Arcane Eye looks like this:
Advantages over Arcane Eye:
Disadvantages over Arcane Eye:
Also note that moving Arcane Eye explicitly requires an Action whereas you haven’t stated this in you spell version, I have assumed the movement works in the same way for both but if not, this could be another advantage for your version of Clairvoyance.
All those are quite situational and will only make a difference in specific circumstances, I don’t think adding this movement speed to the spell makes it better than Arcane Eye but it definitely makes it comparable, therefore I would bump it to 4th level but no higher.
The closest 5th level spell you can compare this to is Scrying, it can also be used to target a location and it is noticeably better as does not have a distance limit, only requires that you know the location. Therefore I would not bump it as high as 5th level.