I feel as though necromancers have little undeath-related spells below 3rd level. Only necrotic damage. I wanted to change that.
While it is relatively simple to extrapolate up and down in spell levels for spells like fireball and burning hands, both because of the "at higher levels" section of the spell and because you can compare to existing spells when determining damage, it is not simple with spells like speak with dead.
Speak with dead does not provide options for higher and lower levels, and I believe this to be because the ability to ask open-ended questions is inherently strong enough that, even with only 1 or 2 questions, it would be a gimme at lower levels. That being said, I think I've thought up a way to mitigate some of that:
Casting Time: 1 action
Range: 10 feet
Components: V, S, M (burning incense)
Duration: 1 minute
You reach to the spirit of a corpse within range, allowing it to answer a single yes or no question. The corpse must still have a mouth and can't be undead. The spell fails if the corpse was the target of this spell or speak with dead within the last 10 days.
Until the spell ends, you may ask the corpse one question that it may only answer with a "yes", "no", or "I don't know". The corpse knows only what it knew in life, including the languages it knew. The corpse is under no compulsion to give you a truthful answer if you are hostile or it recognizes you as an enemy. This spell doesn't return the creature's soul to its body, only its animating spirit. Thus, the corpse can't learn new information, doesn't comprehend anything that has happened since it died, and can't speculate about future events.
Is 1st level appropriate for this spell? If not, what makes it too strong or weak?