Yesterday I DMed a session with a party of four level 1 characters:
druid, sorcerer, monk, barbarian, and a level 1 warlock whose player was absent.
The sorcerer specifically is a new player (less than 12 session of play, grand total). The others are experienced (several years) RPG players but new to D&D 5e.
I played Dragon of Icespire Peak, Dwarven Excavation
The party encountered an ochre jelly and the sorcerer was hit.
I rolled for 2d6 + 2 bludgeoning damage plus 1d6 acid damage, and roll three 6, for a total of 20 damage.
The sorcerer being level 1 with Constitution 14 has 6+2=8HP, so this is insta-death.
Without resorting to some sort of Deus Ex Machina, is there a way to save it?
Apart their spells, the party only own a few potions of healing and the only NPCs presents are two commoner dwarves.
Note: since the player is fond of his character and they are involved in a long term campaign in which this character has a great intro, I did save it (in a reasonable, but not RAW, way) but wonder if I could have handled it differently.
Best Answer
By RAW, that PC is dead, and there is nothing you can do to save them
The situation you describe, with that much damage being dealt to a level 1 PC with that little health, results in insta-death, as you know. There is no RAW way to prevent that, short of somehow being able to reduce the damage (certain classes may have certain features that can do that, reduce the damage taken by other party members, but it looks like none of your party would have had access to such abilities at level 1).
Even a half-orc's Relentless Endurance (the only thing I can of for a 1st level character, if the sorcerer happened to be a half-orc) says "... but not killed outright ...", showing that the intention is that massive damage will kill a character if that much damage has been received.
Avoiding death in the first place is the best way to prevent PC death
The best way to handle this, RAW, is to not hit them so hard at level 1. Level 1 PCs especially (level 2 as well) are very weak and I would recommend pulling your punches when they are still that level. After they reach level 3, they should be able to handle more punishment, but at level 1, they can barely stand up to goblin, let alone a CR 2 ochre jelly!
Looking at that quest, I'm guessing it was either area E5 or E7. For E5 it suggests two ochre jellies! Against level 1 PC? Are they trying to kill off the entire party!? That is well over deadly for a level 1 party. I'm not surprised someone died; if anything, I'm amazed it was just the one death.
In your situation, I would have probably just included one ochre jelly in area E5 (for E7, there is only one anyway so ignore this point if it was E7 in your case). I would have made it go for the barbarian, who can handle it, and I might also have fudged the damage so that it was lower than stated, even if only shy of an "insta-death" by a couple of HP.
You, as the DM, always have the option to use the average damage output of a monster, which in this case is 12, which would be unable to cause insta-death in nearly all cases (unless the sorcerer didn't have very good CON).
As the sorcerer was a new player, I'd have probably gone easier on them for such a tough fight, even mention how tough this thing is (in ambiguous terms, of course; not telling them it's CR, HP or damage output or anything like that), and would encourage them to think about where they want their characters to be positioned, so they can learn their party role.
The experienced players should know what their party roles are already, and hopefully have been coaching this new player in their party role (i.e. you are squishy, keep behind the barbarian, etc).
Slightly related reading on keeping squishy level 1 PCs alive:
my answer to "Keeping the world alive whilst PCs take a rest mid-adventure?"