First and most important: The 5E stealth rules are a dumpster fire. It doesn't matter what the "official" word is. Ask your DM how s/he intends to rule on these questions, and build to that standard.
Now, as another DM, here's my interpretation of the written rules. The 5E SRD states that "you can't hide from a creature that can see you clearly" (emphasis mine). I don't have my PHB handy, but I believe the word "clearly" was added in errata post-release; if so, it dramatically changes the operation of the stealth rules, which formerly required total concealment. Because of things like the Skulker feat and the wood elf's ability to hide in nature, I would not rule that light obscurement (dim light or light mist) is sufficient to hide, but I would allow hiding in situations where you aren't completely unseen.
1) Invisible rogue enters antimagic zone: If the guards are not otherwise distracted and there is no concealment, the rogue is instantly spotted. Night or day, doesn't matter. They can see you clearly, so you can't hide. If you were making a point to stay behind cover even while invisible, and there was cover available, I'd give you a roll; but anyone setting up an antimagic zone to stop invisible intruders is likely to arrange it so there's nothing to hide behind.
If you have the Skulker feat, it's different. Skulker allows you to hide in areas of light obscurement. So if the lighting is poor (e.g., because it's night), you can remain hidden even when the AM field kicks in. Unlike the general stealth rules, this one is really not debatable - if your DM doesn't let you stay hidden in this situation, you should be allowed to exchange Skulker for a feat which has not been eviscerated by DM fiat.
2) Rogue hiding on edge of a roof and peering down: When you poke your head over the edge, you can be seen, but you can't necessarily be seen clearly. Therefore, I would allow hiding.
Now, as another DM, here's my interpretation of the written rules. The 5E SRD states that "you can't hide from a creature that can see you clearly" (emphasis mine). I don't have my PHB handy, but I believe the word "clearly" was added in errata post-release; if so, it dramatically changes the operation of the stealth rules, which formerly required total concealment. Because of things like the Skulker feat and the wood elf's ability to hide in nature, I would not rule that light obscurement (dim light or light mist) is sufficient to hide, but I would allow hiding in situations where you aren't completely unseen.
1) Invisible rogue enters antimagic zone: If the guards are not otherwise distracted and there is no concealment, the rogue is instantly spotted. Night or day, doesn't matter. They can see you clearly, so you can't hide. If you were making a point to stay behind cover even while invisible, and there was cover available, I'd give you a roll; but anyone setting up an antimagic zone to stop invisible intruders is likely to arrange it so there's nothing to hide behind.
If you have the Skulker feat, it's different. Skulker allows you to hide in areas of light obscurement. So if the lighting is poor (e.g., because it's night), you can remain hidden even when the AM field kicks in. Unlike the general stealth rules, this one is really not debatable - if your DM doesn't let you stay hidden in this situation, you should be allowed to exchange Skulker for a feat which has not been eviscerated by DM fiat.
2) Rogue hiding on edge of a roof and peering down: When you poke your head over the edge, you can be seen, but you can't necessarily be seen clearly. Therefore, I would allow hiding.
Last edited: