This question is about the prestidigitation cantrip.
It is not obvious to me what I can do with it, which is why I'm asking what the limits are to soiling objects in 1 foot cubic area.
What are the material limits to soiling an object with the prestidigitation cantrip?
To soil an object is to make something dirty or unclean. If you add a foreign substance, it can be considered dirty, whether that's dirt, mud, or even smudged food.
It's a cantrip, and I understand I can't just make something soiled in anything I want, but it doesn't say "soil an object with dirt." Also, it doesn't say, it cannot be soiled by anything either. So the limits are unclear to me.
Best Answer
All the effects of prestidigitation are cosmetic.
It makes tiny objects, lights, sounds, or smells. It draws shapes or marks on things. Its effects are brief, superficial, and innocuous. It should be impossible to weaponize as anything other than a distraction.
The "soil an object" effect doesn't say you get to choose any specific substance to soil it with. Your intent here isn't to "soil" the arrow anyway; it's to create poison.
Prestidigitation does have a "create things" mode: it will make a non-magical object that fits in your hand, but the object only lasts for one round. So you could create poison, maybe even on a weapon, but the poison will cease to exist a few seconds later. Even if you do manage to get it into your enemy by then, there won't be time for the poison to do much.