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View Full Version : [4e] Probability of Dying or: "Wanted: Someone who can do math."



Dragonmuncher
2009-03-16, 11:14 PM
I don't have 4e, but as I understand it, dying works like this: Once you're in negatives, each turn you make a saving throw. If you roll 11-19, nothing changes. If you roll 1-10, you get one strike against you (three strikes and you die). If you roll a 20, you spring back up, ready to fight.

If these numbers are correct (they might not be, I forget if 10 counts as a "save" or a "fail"), what is the probability of a character dying, with no outside help? It's a question of the likeliness of rolling a 20 before rolling three strikes, correct?

Math majors... assemble!

Artanis
2009-03-16, 11:21 PM
It's 1-9 that you get a strike, not 1-10.

Saph
2009-03-16, 11:30 PM
Ooh! Ooh! I know this one! :)

I started a thread on this a while ago. The question was: If your PC is knocked to negatives and no-one comes to heal or hurt him, what are the chances of him surviving? Ie, what are the chances that he rolls a 20 before three 1-9s?

Here are the results, by saving throw bonus.

+0 saving throw bonus: 27% chance of living
+1 saving throw bonus: 49% chance of living
+2 saving throw bonus: 66% chance of living
+3 saving throw bonus: 78% chance of living
+4 saving throw bonus: 88% chance of living
+5 saving throw bonus: 94% chance of living

The moral is that even something as little as a +1 bonus to saves massively increases your chance of surviving. Interesting, huh?

Getting saving throw boosts in 4e is hard, but becoming steadily easier as WotC put out more and more books, and likely to keep going that way.

- Saph

Oracle_Hunter
2009-03-16, 11:33 PM
The moral of the story: Humans are Awesome (http://tvtropes.org/pmwiki/pmwiki.php/Main/HumansAreSpecial) :smallbiggrin:

Asbestos
2009-03-16, 11:39 PM
Now, since its 3 failed saving throws before your next extended rest...

Saph should probably add in "these are your chances of dying in a single encounter if you have no failed death saving throws yet accrued and no one is healing or hurting you"

Oh, and rolling a 20 lets you spend a healing surge, right? Had a PC in a game I recently DMed that was at negative hp and had zero healing surges left. Saved by one of the few healing abilities that doesn't spend a healing surge of the individual being healed.

Dragonmuncher
2009-03-16, 11:46 PM
Is it that you spend a healing surge, or you get hitpoints back as if you had spent one? That'd be frustrating as hell, if you're down, roll a 20, and still can't get back up because you have no surges...

And only 27%? Wow, I thought it'd be higher.

averagejoe
2009-03-16, 11:49 PM
Math majors... assemble!

You know, I wouldn't think that there are many math majors who actually know much probability. I only know any at all because 1) I'm good at math, so I can figure it out myself, and 2) because I need it for physics.

Ahem, if you'll excuse me, I'll go see if I can't find the point around here somewhere.

Oracle_Hunter
2009-03-16, 11:55 PM
More text for the Text Gods!

Death Saving Throw: When you are dying, you need to make a saving throw at the end of your turn each round. The result of your saving throw determines how close you are to death.

Lower than 10: You slip one step closer to death. If you get this result three times before you take a rest, you die.

10–19: No change.

20 or higher: Spend a healing surge. When you do so, you are considered to have 0 hit points, and then your healing surge restores hit points as normal. You are no longer dying, and you are conscious but still prone. If you roll 20 or higher but have no healing surges left expressed as a negative number[sic], your condition doesn’t change.

Emphasis mine. You merely need to take a rest (either short or extended) to wipe out your Death Tally.

EDIT:
And Cites for the Citation Throne! :smallbiggrin:

Sooner or later, even the toughest adventurers need to rest. When you’re not in an encounter, you can take one of two types of rest: a short rest or an extended rest.

Gralamin
2009-03-16, 11:59 PM
Now, since its 3 failed saving throws before your next extended rest...

Saph should probably add in "these are your chances of dying in a single encounter if you have no failed death saving throws yet accrued and no one is healing or hurting you"

Oh, and rolling a 20 lets you spend a healing surge, right? Had a PC in a game I recently DMed that was at negative hp and had zero healing surges left. Saved by one of the few healing abilities that doesn't spend a healing surge of the individual being healed.

You have to spend a HS. If you have none, your condition doesn't change.

Also note, Warforged have a 0% chance of dying from Death Saving Throws, and a 100% chance of eventually getting up if they have a HS left, since they are able to take 10 on the Saving Throw.

NPCMook
2009-03-17, 12:44 AM
Some Backgrounds and Epic Destinies give you extra death saving throws, you can have a total of 5 depending on the background and Paragon path

TheOOB
2009-03-17, 12:51 AM
Alternatively, convince your GM to let you have a magic item that applies a healing potion when you hit 0 hp

Artanis
2009-03-17, 12:53 AM
Is it that you spend a healing surge, or you get hitpoints back as if you had spent one? That'd be frustrating as hell, if you're down, roll a 20, and still can't get back up because you have no surges...

And only 27%? Wow, I thought it'd be higher.
Remember, that's if you keep rolling and rolling. It'll take an average of six or seven rounds' worth of rolling to get those three strikes (assuming no save bonus), and if you're down that long without help, you're probably pretty boned anyways.

Gralamin
2009-03-17, 01:10 AM
I thought the numbers looked a bit odd, so I ran them (through a program generating 10,000,000 trials), and received the following data (In Recovery (http://p.opsat.net/v/1n1) and death (http://p.opsat.net/v/1n0) format), which seems to match pretty well.

In brief:
With a +X bonus, you have a Y% chance of recovering.
{table=head]X|Y
0|27.0872
1|48.7865
2|65.695
3|78.4132
4|87.4878
5|93.6001
6|97.2943
7|99.2060
8|99.9013
[/table]

Kinda off topic, but I find the person bleeding out after 32 rounds with a +0 bonus pretty impressive.


Some Backgrounds and Epic Destinies give you extra death saving throws, you can have a total of 5 depending on the background and Paragon path

Now running the numbers on 4 and 5 ST. Because I can.

Edit: Here are the results, if Anyone wants me to paste dump, I can.

With a +X bonus, you have a Y% chance of recovering if you have 3, Z% if you have 4, and A% if you have 5.
{table=head]X|Y|Z|A
0|27.0872|34.3576|40.9362
1|48.7865|59.0530|67.2383
2|65.6950|75.9812|83.1914
3|78.4132|87.0417|92.2174
4|87.4878|93.7487|96.8826
5|93.6001|97.4407|98.9757
6|97.2943|99.1953|99.7577
7|99.2060|99.8428|99.9677
8|99.9013|99.99|99.999
[/table]

Asbestos
2009-03-17, 01:49 AM
You have to spend a HS. If you have none, your condition doesn't change.

Also note, Warforged have a 0% chance of dying from Death Saving Throws, and a 100% chance of eventually getting up if they have a HS left, since they are able to take 10 on the Saving Throw.

So a Warforged with negative hp and zero healing surges can effectively be unconscious, but not dead, forever ... I smell a plot hook.

Gralamin
2009-03-17, 02:21 AM
So a Warforged with negative hp and zero healing surges can effectively be unconscious, but not dead, forever ... I smell a plot hook.

Assuming he was never reduced to negative bloodied, yes.

Mauril Everleaf
2009-03-17, 02:43 AM
Actually, with the Warforged, you can either roll or take a 10, you can't roll and then decide to take a ten. So you can't just roll, and then see if it's a 20 (get up to fight), 10-19 (just lay there) or 1-9 (decide to take a 10 instead). Instead, when it's time to make a save, you can choose to roll (and take whatever result is offered) or take a 10 and stay alive for another round hoping that your friendly cleric/warlord/paladin will heal you.

Warforged staying unconscious forever without dying (programmed to always take a ten) would be an interesting plot hook though...

Zemro
2009-03-17, 03:00 AM
I believe the text states something along the lines of "take the better of the die roll or ten."

Which would mean that you can roll then choose, because one would need at least two results to pick the better of them

Unfortunately I don't have my books handy, so I can't be completely positive.

Saph
2009-03-17, 03:46 AM
Remember, that's if you keep rolling and rolling. It'll take an average of six or seven rounds' worth of rolling to get those three strikes (assuming no save bonus), and if you're down that long without help, you're probably pretty boned anyways.

Oh, I don't know. Remember that most characters (both PCs and monsters) don't go around methodically coup-de-gracing enemies after taking them down. At least, not in most games. Unless they've got enough spare time to loot the body, the normal sequence goes "take down enemy -> forget about him and move on."

So having a high save bonus is very useful if things go pear-shaped for whatever reason. After all, you aren't going to win every fight . . .

- Saph

Mauril Everleaf
2009-03-17, 04:30 AM
Zemro, you seem to be right. My group doesn't use Warforged, so I was basing my comment on other rules for taking a ten. My apologies. I guess Warforged just can't die from failed death saves.

Kurald Galain
2009-03-17, 04:53 AM
Oh, I don't know. Remember that most characters (both PCs and monsters) don't go around methodically coup-de-gracing enemies after taking them down.

While that's true, the 4E rules assume that PCs, at least, do go around methodically coup-de-gracing everyone, unless they explicitly say they aren't doing that. This is why monsters die at 0 hp.

Incidentally, this is also why you can do non-lethal damage with a Disintegrate spell, these days...

Sebastian
2009-03-17, 05:19 AM
Oh, I don't know. Remember that most characters (both PCs and monsters) don't go around methodically coup-de-gracing enemies after taking them down. At least, not in most games. Unless they've got enough spare time to loot the body, the normal sequence goes "take down enemy -> forget about him and move on."

- Saph
And it make sense, because PCs are the only ones (more or less) that can survive after going to zero hp so NPCs never expect that someone who goes down b y lethal force to spring up again. ;)

Jokes
2009-03-17, 07:19 AM
Hmm, does Unyielding Company (Legendary General level 30 ability) mean you can keep fighting in negative HP? Since the only way to die is a failed saving throw, Warforged would become immortal as long as the LG is alive. Have a cleric cast something like Cloak of Peace (+5 AC, +10 other defenses) and have the General just stand there.

Oracle_Hunter
2009-03-17, 09:51 AM
And it make sense, because PCs are the only ones (more or less) that can survive after going to zero hp so NPCs never expect that someone who goes down b y lethal force to spring up again. ;)

Unless one of them makes a Knowledge Check on the Warforged and realizes that they're not going to die unless Coup De Graced (since that is a racial trait, as opposed to a special characteristic of PCs). This makes Coup De Grace-ing Warforged a wise tactical decision if the enemy thinks he can one-shot the Warforged.

Thajocoth
2009-03-17, 10:24 AM
"Now, since its 3 failed saving throws before your next extended rest..."
Actually, I believe it's 3 fails before your next rest of any kind, which would include short rests.

This is further effected by another player granting a heal, pouring a potion down the unconscious person's throat, making a heal check to pump their second wind, stabilize them, or grant them a new save... And if stabilized, becoming unstable again if dealt any damage, including that from an ongoing effect... So it's a bit more complex than that simple percentage listed above.

I have not seen a PC die this way. I've seen them come close... But not die.

As for the variable modifiers listed, I'm only aware of the possibility of +1 to the save (human feat). Is there some other way of adding to death saves I'm unaware of?

Artanis
2009-03-17, 10:59 AM
As for the variable modifiers listed, I'm only aware of the possibility of +1 to the save (human feat). Is there some other way of adding to death saves I'm unaware of?
I'm not personally aware of others, but then, I tend not to be aware of lots of things :smallwink:

At any rate, even if there are no other ways, there's at least two good reasons to include higher bonuses in the discussion:
1) Why not? As long as the math is being done, it might as well be done for higher bonuses. Really, the hardest part is figuring out what formula to use. Once you've got that, it's pretty much just "plug n' chug".
2) The fact that at least one exists means that it's possible that others will be added in the future. Remember, there's going to be an awful lot of splatbooks in the future, and an occasional +1 here or there can start to build up.



Edit: extended rest vs. any rest.

PHB 295 says any rest. The errata says nothing to change this. So unless there's some other Officially RAW source of which I'm not aware...

Mando Knight
2009-03-17, 12:35 PM
Unless one of them makes a Knowledge Check on the Warforged and realizes that they're not going to die unless Coup De Graced (since that is a racial trait, as opposed to a special characteristic of PCs). This makes Coup De Grace-ing Warforged a wise tactical decision if the enemy thinks he can one-shot the Warforged.

And if you're going to let a monster CDG the Warforged, make sure that at least it or one of its compatriots makes the knowledge check. I'd make it a DC 25, DC 30 for Paragon, and DC 35 for Epic (see page 180 of the PHB), as it would seem to fall under "Resistances and Vulnerabilities" rather than the lower two...

ericgrau
2009-03-17, 12:42 PM
Oooh, ooh, math! <Ahem>

10-19 essentially cause a re-roll. It may take longer but it has no impact on your chances of dying in the end. Thus there are only 10 possibilities: 1-9, and 20. Your chance of getting a strike is 9 out of 10. You multiply the chance of each strike together to get the chance that all the strike(s) will happen without a 20. So for 3 strikes the chance is (9/10) x (9/10) x (9/10) = 729/1000, or 72.9%. That also means a 23.1% chance of living. Saph got the same result assuming a +0 saving throw bonus.

Artanis
2009-03-17, 12:49 PM
I never liked knowledge checks getting harder with level...

Remember, it's not the PC they're trying to figure out, it's the PC's race. There's Warforged who don't even have a level...the fact that they don't bleed to death could easily be simple common knowledge, no matter how high-level a particular Warforged PC is.

Honestly, I think that something like that would get easier to know as the PCs go up in level. Not everybody would start off knowing about Warforged, but as word got around about Shiny the Warforged Fighter who has never, ever bled to death, monsters would start to figure out that a Warforged who comes after them has to be finished off, and not just left to die.


Edit: Ninja'd :smallfrown:

This is in response to Mando Knight

Oracle_Hunter
2009-03-17, 01:01 PM
Monster Knowledge Checks

Monster Knowledge DC
Name, type, and keywords 15
Powers 20
Resistances and vulnerabilities 25
Paragon tier creature +5
Epic tier creature +10

I believe Warforged are Heroic Tier creatures, so you would need a DC 20 check to identify this particular property. Resist/Vulnerable is a very specific part of the MM entry - Racial Traits are listed as powers, like Sneaky for Kobolds.

The nice thing about this table is that knowledge is tied to the Tier of the creature, not your level; most people know a goodly amount about common (Heroic) monsters, but Paragon creatures are more about myths and legends. Epic Tier? Never heard of 'em :smalltongue:

Artanis
2009-03-17, 01:27 PM
Just to clarify my position, because I realize my wording wasn't perfectly clear:

I meant that IF it's homebrewed so that the DC changes, then the logical homebrew would be for the DC to get lower as the PCs' level gets higher.



(Note: this is not in response to OH, just to my realization that I could've been a bit clearer)

Douglas
2009-03-17, 01:42 PM
Hmm, does Unyielding Company (Legendary General level 30 ability) mean you can keep fighting in negative HP? Since the only way to die is a failed saving throw, Warforged would become immortal as long as the LG is alive. Have a cleric cast something like Cloak of Peace (+5 AC, +10 other defenses) and have the General just stand there.
If you ever get down to negative your bloodied value you just die with no save. So no, even if the abilities you mentioned work that way (I'd have to go home and look them up) it's not immunity to death.

NecroRebel
2009-03-17, 02:12 PM
If you ever get down to negative your bloodied value you just die with no save. So no, even if the abilities you mentioned work that way (I'd have to go home and look them up) it's not immunity to death.

The text of Unyielding Company (from Martial Power):
Unyielding Company (30th level): While you have at least 1 hit point, allies within 20 squares of you do not fall unconscious at 0 hit points or fewer and cannot die because of negative hit points. Allies at 0 hit points or fewer still make death saving throws as normal, and they can die as a result of failed death saving throws.

So yes, as long as you don't fail death saving throws, if a Legendary General is still up, you don't die. Warforged can make it so they never fail death saves, so a Warforged army with at least one level 30 Legendary General would be able to fight indefinately despite damage as long as they could keep the General on his feet.

Bear in mind, the level 30 epic destiny features are basically supposed to be game-breakingly powerful. Considering some of the other stuff level 30 characters can pull off, this is really just par for the course.

Tokiko Mima
2009-03-17, 02:23 PM
Another way to look at a death saving throw is to break it down to a 50% chance of just lying there and nothing happens and a 50% chance of some event that progresses you towards or away from death. Separating that possibility from the roll (i.e. cutting out the 10-19), you can now see how death saves work.

Assuming you did not hit the 'nothing happens this round' 50% roll, you have a 10% chance to recover and a 90% chance to get worse. The odds that recovery event will happen are:

100% - (90% ^3) which is 1 - (.9^3) = 27.1%

Now, a +1 on the roll shifts everything up, and makes a roll of 19 and 20 successes, while only 1-8 are now failures. So you have a 2 of 10 chance of success versus a 8 in 10 (80%) chance of failure.

100% - (80% ^3) = 48.8%

With a +2 you now are successful on 18, 19, and 20, and fail on 1-7 (70%) And so on...

+2 = 65.7%
+3 = 78.4%
+4 = 87.5%
+5 = 93.6%
+6 = 97.3%
+7 = 99.2%
+8 = 99.9%
+9 = 100%

I think the math agrees with the experimental data someone else posted. Hope that helps!

Douglas
2009-03-17, 02:32 PM
Huh, I guess it does work, then. Fortunately, they did think to word it so that two Legendary Generals can't keep each other up through this ability. If it had said "While you are conscious" instead...

ColdSepp
2009-03-17, 03:30 PM
Just to clarify my position, because I realize my wording wasn't perfectly clear:

I meant that IF it's homebrewed so that the DC changes, then the logical homebrew would be for the DC to get lower as the PCs' level gets higher.

(Note: this is not in response to OH, just to my realization that I could've been a bit clearer)

To be clear, specific DC's don't change, only general ones. If there is a cliff outside of the the Village of Backwaterville that the PCs have to climb at level 1, and it's a DC 15 Athletics, if they come back at L30 it's still a DC 15. However, when the go to Shadowfell Cliffs of Doom at L30, the DM sets the DC for these cliffs based on the guide on pg. 42.

Artanis
2009-03-17, 04:08 PM
I was referring to the knowledge checks that Mando Knight proposed regarding knowing about Warforged never failing death saving throws.

Sebastian
2009-03-17, 04:31 PM
Unless one of them makes a Knowledge Check on the Warforged and realizes that they're not going to die unless Coup De Graced (since that is a racial trait, as opposed to a special characteristic of PCs). This makes Coup De Grace-ing Warforged a wise tactical decision if the enemy thinks he can one-shot the Warforged.

BY the way, maybe I remember wrong, but there is not "coup de grace" in 4e. you must keep hacking 'til he reach negative bloodied hit point, you must even roll to hit, IIRC (even if with a considerable bonus and all your hit are auto criticals).

This of course barring erratas, or my faulty memory.

Sebastian
2009-03-17, 04:40 PM
The text of Unyielding Company (from Martial Power):

So yes, as long as you don't fail death saving throws, if a Legendary General is still up, you don't die. Warforged can make it so they never fail death saves, so a Warforged army with at least one level 30 Legendary General would be able to fight indefinately despite damage as long as they could keep the General on his feet.


They could turn him to stone.
While petrified technically he still alive and still have his hit points, plus he gain resistance 20 everything.

Or, even better, take 2 warforged legendary generals. As long as they are 20 squares from each other they are virtually immortals. :D

edit aww, never mind they must have at least one hit point for the power to work. Say, if you use an effect that give temporary hit points on someone at negative hit points, what does happen?

Oracle_Hunter
2009-03-18, 07:38 PM
BY the way, maybe I remember wrong, but there is not "coup de grace" in 4e. you must keep hacking 'til he reach negative bloodied hit point, you must even roll to hit, IIRC (even if with a considerable bonus and all your hit are auto criticals).

This of course barring erratas, or my faulty memory.

It's actually on PHB 288 - listed right in the Table of Contents even :smallsmile:

Of course, your description is correct - though it isn't that different from the 3E Coup De Grace rules (http://www.d20srd.org/srd/combat/combatModifiers.htm#coupdeGrace) save for the Fort save clause.

Oh, and if you deal the target's Bloodied Value in damage on a single attack, they die outright; this is why you have Backstabbing Rogues with Vicious Daggers deliver your Coup De Graces :smallamused:

EDIT: As for monsters delivering Coup De Graces, let's go with an Orc Raider (Skirmisher 3) vs. a Warforged Fighter (CON 18, HP 23+6L). On a Coup De Grace, the Orc does 15+1d12 damage - enough to kill a LV 1 Fighter outright. At maximum, the Orc does 27 damage, which is good up through a LV 5 Fighter. Heck, even if the Orc doesn't slay him outright, he only needs to drop the Warforged to -Bloodied to kill him; 2-3 swings at the most.

Oh, and regarding Temp HP

If your current hit points are 0, you still have 0 when you receive temporary hit points