A silvery beam of pale light shines down in a 5-foot-radius, 40-foot-high cylinder centered on a point within range. Until the spell ends, dim light fills the cylinder.
When a creature enters the spell’s area for the first time on a turn or starts its turn there, it is engulfed in ghostly flames that cause searing pain, and it must make a Constitution saving throw. It takes 2d10 radiant damage on a failed save, or half as much damage on a successful one.
A shapechanger makes its saving throw with disadvantage. If it fails, it also instantly reverts to its original form and can’t assume a different form until it leaves the spell’s light.
On each of your turns after you cast this spell, you can use an action to move the beam up to 60 feet in any direction.
At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d10 for each slot level above 2nd.
* - (several seeds of any moonseed plant and a piece of opalescent feldspar)
It is available to clerics, choose "twilight domain" subclass and it's a "always prepared" spell.
I smite thee with the power of LUNA!
Please add this to the Lunar sorcerer subclass!
Ok. This seems to be one of the few low-level abilities that could detect a mimic. Assuming you're looking for one.
Per casting, you can pass it over ten 5ft squares in a minute. Great if you're trying to detect if a mimic is hiding in a room of furniture.
Sure, though arguably just throwing a bunch of rocks and seeing what yelps is just as effective and doesn't use a spell slot.
Spiritual weapon is bad.
Ok, but WHY can this revert shapechangers, especially werewolves and the like which transform ON the full moon?
If moonbeam travels in a straight line across 3 creatures in that straight line do all of them have to make the saving throw or just the one it stopped on?
None of them at that moment. Only the final creature would need to make the saving throw, and only at the start of it's turn (or if before the start of that turn, the creature was moved into the beam.) This is the key here: the movement element must be associated with the creature, not the beam itself.
This Sage Advice does a pretty good job of explaining it.
With a 5' radius circle covering 4 squares, it could technically hover over up to 40 unique 5' squares over the course of a minute.
That was the 2014 version that says "When a creature enters the spell's area for the first time on a turn or starts its turn there, it is engulfed in ghostly flames that cause searing pain, and it must make a Constitution saving throw. It takes 2d10 radiant damage on a failed save, or half as much damage on a successful one."
2024 received a major buff with the new wording
"A creature also makes this save when the spell's area moves into its space and when it enters the spell's area or ends its turn there. A creature makes this save only once per turn."
2014 was dependent on the creature moving or staying in the area of the spell when it started it's turn so when you casted moonbeam in 2014 it didn't do damage right away vs 2024 which allows for the damage to occur right when you cast it, because the spells area enters the creatures space, when the creature moves into it or when it ends its turn there.
Sage advice relates to the 2014 spell. I think you should compare to the new 2024 description.
The advice you’re currently giving is for the old spell (admittedly it’s the spell we’re currently replying to).