Let's talk about medicine/physiology of DayZ

[HrcAk47 11]

Hi everyone.

First of all, I'd like to mention that this mod seems to be the real deal. The game Stalker, Resident Evils 3+ and the rest should have been. As a huge zombie fan - I believe that this is the second best thing to a real-deal zombie apocalypse!

But, in real life, I'm a medical student, and that also gives me a slightly different viewpoint to the whole thing... Therefore...

I shall suggest some ideas regarding the whole health/nutrition system.

1) Oh my. A zombie bit me and i bled for a minute. Nothing that 30 cans of beans can't fix!

Bleeding is an injury that lowers your blood volume (as represented ingame). Blood packs idea is good, simplified to an acceptable measure and it works good - nothing wrong there! However, what rustles my jimmies is the food-to-health system.

I shall now briefly explain what happens during blood loss. When the baroreceptors in carotid sinus detect a drop in blood pressure (due to bleeding), a couple of body systems activate. First - the adrenaline (epinephrine) system. It works immediately and constricts the blood vessels. That raises the blood volume and increases the cardiac output, so that we don't bleed out the very minute we're injured. But, it doesn't last forever, so the renin-angiotensin system activates. Angiotensin is another powerful vasoconstrictor which lasts longer and constricts our blood vessels even further, allowing for even greater amount of blood available for central circulation. The last system, however is the antidiuretics system (vasopresine). To keep the blood volume from dropping, after a couple of hours our body starts with fluid retention - that means, kidneys will produce only MINIMAL amounts of urine - all in order to keep the blood volume up and running. Therefore: liquid=blood=health.

We stay alive due to our blood volume, which can be upped with extra blood intravenously, or extra ingested fluid. In come the canteens and the sugary drinks. Maybe that water should give a minimal bonus of 50 blood when taken. But, over the rate of 1 hour, it will raise the blood volume for 2000 units (per canteen, and given that the player had properly bandaged himself) Also, if the player is properly hydrated, he could get a minuscule blood bonus, like 100/hr. That's dandy for those small injuries, like single bites that leave you at 11900 instead of 12000 health. :)

As for the food, I agree with the idea that it could immediately give you 200 blood bonus. But, i suggest that the "hunger" drops health, affects stamina (when it gets implemented), etc. - and that the green health status should also give 100 blood/hr.

2). Nutrition (and hydration) should be affected with the amount of runnning and action (Boy, killing zombies all day sure makes you hungry!) that the player had performed.

Speaking of which, I have a pair of ideas regarding food. There is plenty of different cans - but they all have the same effect! I suggest a "ranking" system. So, Beans/Pasta cans, being the most common, should give a health bonus of, say, 150 - but, they could fill the hunger meter to the top. Frank and beans, having them tasty frankfurters inside, should give you 300 health immediately AND fill the hunger meter to the top, being the reasonable combination of meat and carb filler. Sardines, being a rare and tasty treat, should fill blood meter by 500, but the hunger meter by 1/3, due to sardines coming in small cans.

The food effect could be upped by heating food - if consumed 15 mins after heating, they could give a double health bonus. Also, it could give a purpose to a new set of tool items - like a skillet or a pot.

And some extra variation in food could also be dandy. Military camps should have some Meals, Ready to eat scattered around. They could have many uses, and therefore be a prized possesion in a zombie filled world.

As for the sugary drinks, they should have the small effect of boosting blood (say, 500/hr), hydration, and instantly refilling stamina.

3). God dammit. I took so much damage, I am shaking badly, out of painkillers, I can't see properly... and the nearest town is, like, 20 kms away. Wat do?

Adrenaline (epinephrine) is a very dandy hormone. It's called "fight or flight" hormone. As discussed earlier, it prevents you from bleeding out immediately. It also prevents you from collapsing immediately after an injury and gives you strength to get away from a dangerous situation. So, i suggest that the pain symptoms start 30-60 seconds after an injury. Allowing you to pop those remaining two zombies/finish off the bandit bastard.

Afterwards... Difference between morphine and painkillers is in that that morphine is used for acute pain alleviation (which means, it works instantly), and the painkillers for chronic pain alleviation (which means, they are used for long term pain control. But they are not as efficient as morphine).

My idea is this. After injury, player can use morphine OR painkillers for all pain-related issues, depending on what he has in inventory. But, morphine will remove all pain symptoms immediately, for 20 minutes (afterwards he'll start feelin' bad again), while painkillers will need a lot of uses to reach the same effect and some time to start working (say, 10 mins, and they would last for 30 mins). If taken simultaneously, player will instantly get better (due to morphine), and won't have issues later (due to painkillers). Painkillers should also be used, say, every 30 mins to combat the pain problems (bw screen, shaking, blur...), until the blood meter is taken to a reasonable level.

Oh and, maybe the fractures could be fixed using splints, like pieces of wood, etc. They could be found in the "junk" spawns. :)

Also, painkillers should have multiple uses (about 10 per box seems cool). I find it strange that players eat a box of them at a time. That's not very... nice, in real life.

So... yes. Those are my ideas. Thank you for reading, and... Sorry for the long post. Hopefully the devs will like these ideas. :)

Peace, love, and death to bandits!

~HrcAk47

[Mutonizer 78]

Very interesting stuff that I'd like to see in-game, thanks for that.

Can I suggest making this into a more concise chart/table or something, without the text explanation, to structure it? I mean I'm sure this kind of stuff can go into Dayz someday if Rocket's interested but a more structured layout might make it easier to analyze at a glance and allow for implementation.

++

[terrvik 2409]

I really like your ideas but I'm sad to say that many wont read because it's so long. I read it though, and it's good stuff. :)

A question for you: How realistic would it be to be addicted to morphine if you choose to use it to much? Or even painkillers? So that you would have to seek it out otherwise the shake/blur-thing will happen even without you getting hurt.

[fapoo 2]

Due to the realism that the ARMA series is known for, Day Z could implement huge amounts of realism.

But is there a limit?

I mean how many blood packs can you find in one town? And what if they are not the same blood type as you?

So many realistic angles we could work into the game that would add that kick of realism that makes Day Z so great but where could it end?

Or is the Day Z staff destined to code forever trying to some sort of Matrix Apocalypse Mod?

[dreadstorm 3]

Broken bones should be fixed with a splint that slowly returns proper movement (improved with morphine). If I've got a broken ankle, morphine doesnt fix the break- I'd like to see something like this implemented

[Butters (DayZ) 0]

HrcAk47 has made an excellent post, scaling food isn't a hard argument, and military meals is a fggn great idea.

particularly like the multiple use painkillers- yes, the pain should return! you should need more! multiple use would give you an inventory advantage, but having the pain return should balance that out!

..And what if they are not the same blood type as you?

heheh, yeah, that would be a kicker, huh? spamming chat trying to find Type O?

i'll add a couple things that came to me immediately starting the game:

-soda dehydrates you. in a game world with running water, stores, etc, you take it for granted soda represents something, but in this sparse world it stood out more as SODA.

-a few days with less food and your stomach shrinks= you are less hungry. you get a 'normal' sized meal again, and the next day you are constantly hungry all over again, until it shrinks back.

i'm not suggesting these as additions, just throwing it out there. there's never *really real* realism, after all-- i don't imagine morphine improves your aim in real life? and i wouldn't like to have to search towns for a can opener.

[jwolozin@gmail.com 0]

This is beautifully written and should be implemented. ACE mod probably has the best bleeding out system.

[Stubbies 67]

WALL OF TEXT. NGAAAAAAAAAAAAAAAAAAAAAH