@JeremyECrawford Summon Lesser Demons can summon "Four demons of challenge rating 1/2 or lower", but there are no CR 1/2 demons. What gives?

— Tire Fire DM (@dasuber) November 16, 2017

A dretch and a manes are both lower than CR 1/2. As for a demon right at CR 1/2, we future-proofed the spell, in case such a demon does appear. Future-proofing is on our minds whenever we refer to CR ranges. #DnD https://t.co/jfyGUnczJo

— Jeremy Crawford (@JeremyECrawford) November 16, 2017