This article was first broadcast in Episode Eighteen on 4th April 2018.
Ryu: So, we’re in the Gnomish Workshop… Why are we going to die?
Ostron: Well, I’ve got this piece about dice math I’ve written..
Ryu: Okay, nevermind, I get it now.
Ostron: Oh come on, dice math is fun! Besides, it might not be that easy.
Lennon: We can’t use the sweet embrace of death to escape your dice math?
Ostron: Not always…
… you see, D&D is not considered a game where death of a character is likely. Assuming the DM isn’t actively trying to make it happen, permanent death of a character requires some extra effort. But Dungeon Masters and players alike may wonder “exactly how hard is it to die?” Fortunately, as with most things in the workshop, math has an answer for us.
Anyone who’s read the appropriate section of the Player’s handbook knows that there’s a world of difference between reaching 0 HP and being dead. However, there is that annoying caveat: if your character takes damage equal to twice their hit point total, you go straight to dead. So, how likely is that to happen?
Note: Ostron had to work with some abstractions here because he didn’t have a spreadsheet with the average damage values for every creature in 5th edition (note – if someone has this, he will buy you things for a copy). Instead he used the table on page 274 of the Dungeon Master’s Guide. That table is supposed to be used to determine the CR for a custom creature and includes damage ranges per round. For this exercise, Ostron used the lower value in the range.
First of all, everyone will be gratified to know that it should be mathematically unlikely a creature with a CR of 0 will instakill any character. So that whole thing about ocean crabs being the “deadliest catch” is officially debunked.
In general, if a character is facing a monster with a CR equal to its level, any time the monster rolls a critical hit there is a decent chance that instadeath damage can happen. If a character is facing a monster with a CR that is twice their level, instadeath damage is possible from any normal hit.
Obviously there are a huge number of caveats to that information. Barbarian hit point totals make them more likely to avoid instadeath than, say, Wizards. The instadeath calculations were based on an average of the average hit point totals from all of the classes, so your mileage will vary quite a bit. Also, the CR system is at best…loose. Damage is not the only factor; some creatures have a high CR because of high AC and Hit point totals rather than damage. A baboon, for example, is CR 0 mostly because it has 3 HP; it can do 1d4 + 1 damage per hit. A maxed out critical from the monkey can instakill a level 1 wizard if they ended up with a negative Constitution modifier.
Assuming a character avoids the instadeath hits described above, if they drop to 0 HP they start making death saving throws. In this situation, the math is on the side of the character surviving, but only slightly. Each death saving throw has a 55% chance of succeeding. In fact, there’s only a 9% chance that a dying character will roll 3 fails in a row.
However, please remember the gambler’s fallacy here. Every time you roll a death save, you have a 45% chance of failing. That 9% chance of failing three in a row is based on every death saving throw everywhere. In July of 2017, Roll20 alone recorded over 48,000 players. That means about 4400 of them will fail the first three death saving rolls they make.
If one of your party mates is down, it’s worth going to stabilize them. Even if you have a plus nothing to your Heal skill, you still have a 55% chance of getting them stabilized.
Okay, so, the character’s dead, and that obviously presents problems. Sometimes.
The presence of clerics means that death is not permanent in general, even within one’s own party. There are currently four spells in 5th ed that allow a character to be returned from death, usually with a commensurate penalty until four days or so have passed. The challenge is that all of them have a level restriction and they cost money.
The budget “you’re not dead” spell is Revivify. You have to cast it within a minute (10 rounds of combat by the strict definition) and it costs 300 gold. Unless characters find a scroll, no player character is going to have this spell available before level five. If the DM is following the recommended distribution of treasure from the Dungeon Master’s Guide book, affording the gem component of the spell shouldn’t be an issue for any one character, but if everyone’s been going on shopping sprees, pooling resources may be required. Fortunately that is the only spell with such harsh time restrictions. The next level up, Raise Dead, has a 10 day time limit and the others’ limits are measured in centuries.
In general, being dead before level 5 presents the most amount of trouble; you probably have to haul a body to a temple or shrine for resurrection (assuming your campaign has such things) and probably empty your money pouches when you get there. After level 5 it becomes considerably easier to “get over” being dead. Some people actually believe it’s too easy and death isn’t really a deterrent at that point.
That’s given rise to a few extra rituals and requirements that make resurrection more difficult or provide more lasting consequences. Critical Role, for example, implemented a popular system where resurrection of a character requires other characters to bring meaningful offerings and make additional skill checks. The Dungeon Master’s Guide itself has a “Lingering Injuries” table where lasting effects can be applied if characters fall to 0 HP or severely fail a death save, and Xanathar’s Guide to Everything added even more options to make death and/or resurrection more punishing. Whether death is too easy, too punishing, or just the right amount of lethal is something you’ll have to figure out yourself in your own game.
Ostron: See! Not that easy after all. Now, here’s what I’ve been working on “Every die is, at heart, a probability equation. On a d6, you have a one in six chance of rolling any given result on the die. On a d20, it’s a one in twenty chance. A one in twenty chance theoretically means…
Lennon: I can’t believe I’m going to say this, but–
Ryu: — you want me to get the hat?
Lennon: Mmmhmm, it’s for his own good