D&D 5E Knocked unconscious in water

[Hawk Diesel]

I agree with you about DM latitude. It seems to me, though, that rulings like the ones you’ve given here make the game less predictable for players. If you’re going to adjudicate sleep, not according to the spell description, but according to a principle that, as far as I can make it out from what you’ve said here, is that anything that can wake you up from normal sleep will also wake you up from magical sleep, I would want to know that up front so I could avoid taking that spell or using it in the wrong situation. Likewise, if dropping to 0 while submerged in water incurs disadvantage on death saves, I would want that information going into any situation where that’s a possibility because it makes water more dangerous than it would be otherwise, and I should be given the opportunity to avoid that.

So while I support the DM being empowered to make rulings in fulfilling the role of the game’s adjudicator, I think rulings that disempower players or worse, come off as displays of DM power, are undesirable.

@Hriston I don't see any of the rulings that I've made as disempowering to players. There is nothing in the sleep spell that says that magical sleep is any different than normal sleep outside of that fact that one falls asleep. The description of the spell provides circumstances that cause an affected creature to awaken. Unlike 3/3.5, 5e is purposely made not to be hyperspecific. The rules do not need to list every circumstance or interaction that will trigger or relate to every mechanic. And the existence of higher level spells that mimic not being able to be snapped out of the effect (ie hold person) causes me to believe that the sleep spell is not meant to force a person to remain asleep through situations that would cause any other person to awaken from sleep.

Additionally, part of D&D is having to deal with the unknown and manage it. A player shouldn't know every threat or understand every enemy that is encountered. Some things need to be interacted with or studied to be understood within the game world. Just because you see something in a game that looks like a beholder, that doesn't mean that a DM must maintain the mechanics presented in the Monster Manual. A DM could have the beholder function more like a dragon mechanically. And a player shouldn't necessarily know that unless they knew this specific beholder. Because the Monster Manual provides average examples of creatures, it does not force a DM to ONLY represent creatures in a singular way as outlined in the Monster Manual.

Additionally, while a player may not know what happens if they drop to 0 hp into water, they don't need to know exactly how that will work out. They should probably understand that it is likely to be worse than dropping to 0 hp on solid ground. Especially since a DM choosing a battlefield not just for cosmetics, but likely to also create the need to strategize differently and create challenges that the players wouldn't otherwise encounter.

D&D is not a video game. Yes, mechanics exist. But the DM is not just a processor of taking inputs and creating outputs based on existing mechanics. The DM is the individual chosen and trusted to cultivate an experience that is fun. That doesn't require for players to know how every ruling will go, so long as the DM us being reasonable and consistent.