The wording for Horizon’s Razor Edge states that “The target may call CLEAVE once each day with any melee weapon except a pike.”
The wording for daggers states that “The only difference between a dagger and a one-handed weapon is that you cannot use a dagger with any heroic skills or with enchantments suitable for one-handed weapons.”
Using a purely procedural train of thought, my brain would read this as a player being able to use a dagger to Cleave when under the effects of Horizon’s Razor Edge, even though it would usually be unable to. Since the wording for the ritual just gives the ability to make the call (meaning it isn’t a heroic skill giving the ability) and it doesn’t state that it applies specifically to one-handed weapons, the exclusionary clause in the dagger description wouldn’t apply to the ritual.
That’s not to say I actually plan on going around using a dagger to throw around cleaves. Was just curious about the interaction and whether the rules for the game are strictly intended as worded, or if they follow a “spirit of intent” approach where it allows for flexibility for referees to say no to something even though it follows the “letter of the law”, as it were.
A follow up to this, I assume that you can’t use it to cleave with a wand, rod, or staff due to them being “implements” and not “weapons”?