I was reading the Channel Divinity abilities of the Oath of Vengeance paladin on my character sheet on D&D Beyond. Under Vow of Enmity, it says:
As a bonus action, you can use your Channel Divinity to choose a creature within 10 ft. and gain advantage on attack rolls against it for 1 minute or until it drops to 0 HP or falls unconscious.
Here is where I'm seeing this text in D&D Beyond, on my character sheet:
Can Vow of Enmity be used on an invisible creature, since it is not written that I need to see it?
For contrast, Channel Divinity: Abjure Enemy says the following:
As an action, you can choose one creature within 60 ft. of you that you can see to make a WIS saving throw (14). Fiends and undead have disadvantage on this saving throw. On failure, the creature is frightened and its speed is reduced to 0 (and it can't benefit from bonuses to speed) for 1 minute or until it takes any damage. On success, the creature’s speed is halved for 1 minute or until the creature takes any damage.
However, it doesn't look like Vow of Enmity specifies this.
Best Answer
Vow of Enmity requires you to see the target.
The actual description of the Oath of Vengeance paladin's Vow of Enmity Channel Divinity option says (PHB, p. 87; emphasis mine):
Here is a photo of this feature as it appears in my physical copy of the PHB:
However, if you read this ability from the character sheet on D&D Beyond, the phrase “you can see” is notably absent from the description:
This is a mistake in D&D Beyond's character sheet; ability descriptions shown in character sheets (snippets) don’t always match exactly the full descriptions found in the books. If you click on the feature description within the character sheet, it will bring up the full feature description in the sidebar.
As I've quoted above, the full official description of this feature includes the phrase "you can see" – so you must be able to see the target.