How does this homebrew cantrip compare to other cantrips, and certain levelled spells?

Question

There aren't many cantrips that I know of which inflict a status effect, so I wanted to create one. The aim is to make it strong enough that it's viable, but not so strong that it's a must pick.

Here is the cantrip in question. I haven't settled on a name, so I've put both.

Fright/Nightmare
Illusion cantrip (Sorcerer, Warlock)
Casting Time: 1 action
Range: 60 feet
Components: S, M (sleep dust)
Duration: 1 round

You briefly implant terrifying visions into a creature's mind. A construct or undead is immune to this effect. The target must succeed on a Wisdom saving throw or become frightened of you until the beginning of your next turn.

The number of creatures you can target with this spell increases by one at 5th (2 creatures), 11th (3 creatures), and 17th level (4 creatures).

The levelled spells to compare against are cause fear and fear, which both also cause the frightened condition.

Cause fear is a first level spell that targets one creature, and lasts a minute with concentration, allowing a save at the end of the creature's turns. In comparison, this cantrip also only targets one creature, and only lasts a round.

Answer 1

Seems quite strong

The main effect seems strong, as it can effectively impose disadvantage to an enemy of any challenge rating and also limit their movement options due to them being Frightened.

A frightened creature has disadvantage on ability checks and attack rolls while the source of its fear is within line of sight. The creature can't willingly move closer to the source of its fear.

The disadvantage compares to the same effect in Vicious Mockery. Note that the disadvantage of Vicious Mockery only applies to "the next attack", not all attacks and all ability checks, so this is already stronger than a popular benchmark cantrip.

The movement limit you could compare to the damage of 1d4 from Vicious Mockery. Depending on the positioning of your allies, and on their ability to use missile attacks, this may effectively remove the enemy from the fight for a round. I think in most cases, this is clearly stronger than the Bard cantrip. Few other combat oriented cantrips like fire bolt would be able to achieve that for any enemy beyond CR 1/8.

It uses your action every turn, trading off against the enemy's action, and they get a save so you may trade in vain, so I think overall while strong the base effect is balanced.

The ability to scale this to multiple enemies is however too strong. To achieve this with cause fear, you would need to cast it as a level 2, 3, or even 4 spell. From an action economy perspective, you trade 4:1 eventually. If you want to retain that, I at least would recommend to follow the wording of cause fear for clarity and demand that "The creatures must be within 30 feet of each other when you target them.".

I would remove the scaling if your goal is to have this be a viable, not a "must pick" cantrip. The damage cantrips scale to keep up with the growing hit points of the avereage enemey. This one is based on a saving throw that has your increasing DC to back it up, and the effect works on opponents no matter how much hp they have. It will not need such support.