If I use Silent Image to simulate the spell darkness, is it revealed as an illusion when objects pass through? If a person walks into it, they can immediately see it's an illusion (it doesn't actually block light). Outside observers would still need to use their action to investigate as specified in the spell. Arrows passing through darkness isn't a giveaway. #WotCStaff
— Dan Dillon 👥 (@Dan_Dillon_1) November 13, 2019
Well, I thought darkness is quite different. It turns out it is somehow, though not as good as I has expected. The darkness spell is generally going to be a better choice. It can't be investigated and it fills a significantly larger area. (15-foot-radius sphere for Darkness vs 15-foot cube for Silent Image).
— Dan Dillon 👥 (@Dan_Dillon_1) November 13, 2019