Sleep ammunition would have to be homebrewed. As Coder said, there are a few poisons in the DMG that can incapacitate. If you are just looking to incapacitate a creature you have: Drow Poison (injury), Essence of Ether (inhaled), Oil of Taggit (Contact), and Torpor (ingested). These are the 4 poisons in the DMG that incapacitate creatures. Incapacitating a creature is pretty much putting them to sleep since in some of the descriptions of the poisons they can be shaken awake or are not incapacitated any long if they take damage. I hope this helped.
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Is there any legal method of acquiring Ammunition laced with sleep inducing spells or potions/poisons?
Define "legal". The DMG has some poisons that can incapacitate or knock creatures unconscious. Acquiring them will be up to your DM.
Not Homebrew or UA.
Sleep ammunition would have to be homebrewed. As Coder said, there are a few poisons in the DMG that can incapacitate. If you are just looking to incapacitate a creature you have: Drow Poison (injury), Essence of Ether (inhaled), Oil of Taggit (Contact), and Torpor (ingested). These are the 4 poisons in the DMG that incapacitate creatures. Incapacitating a creature is pretty much putting them to sleep since in some of the descriptions of the poisons they can be shaken awake or are not incapacitated any long if they take damage. I hope this helped.
Remember this is a game and it's suppose to be fun for everybody. Let's all have fun and kill monsters.
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