Oh flip, it's here. 

This is the Many A True Nerd "You Only Live Once" Fallout 4 mod. This mod was created because I wanted to play Fallout 4 Survival mode using Jon's MATN YOLO rule set.

Rules of a YOLO Run are:

• You do not heal any lost HP.
• You do not heal any crippled limbs.
• You do not remove any diseases (they go away over time in FO4).
• You do not cure any addictions.
• You do not remove any radiation.
• You do not take any drugs/perks that buff your Endurance.
  

This mod removes the non-player controlled elements of the game that would violate those rules. Let me show you its features. 


Brief summary:

• All food/water HP healing has been removed. 
• All health/limb healing from sleeping has been removed.
• All Endurance buffs that are NOT in the player's control have been removed. 
• All Endurance debuffs that are NOT in the player's control have been removed. 
• Infection has been removed from the game, all other diseases remain in the game. 
• I created a consumable item called the "Vault-Tec Blood Tester" that will display the numerical value of your current radiation level. 
• Healing when you level up has been removed, but a word of Caution on this below. 
  

Updates:

UPDATE #1:

• The Legendary Armor that gives +1 STR & +1 END will mess up your HP when you level up. You'll be healed 1hp a level. The +1 END never altered HP so I left it in, but it does seem to mess with the scripting math. Credit to TheCretanArcher for finding this bug. 
• Version 2 will fix this issue, and it will also address DLC items so Version 2 will have the DLC as required dependencies. 
• I have added a Version 1.1. It includes the Legendary armor fix, but no DLC items altered. 
  

UPDATE #2:

Version 2 of this mod is live. It changes the following:

• This version requires the DLC and includes everything in Version 1.1. 
• Endurance has been removed from the Legendary Armor that is +1 STR & +1 END. It is now just a +1 STR armor. 
• All END buffs from clothes (outfits and hats) have been removed, so you can wear what you want. In base game, Far Harbor, and Nuka World. 
• DIMA's chest piece reward has +1 Endurance. I wasn't able to remove that, so avoid that armor or it will mess up your HP. (fixed in V3)
• Buffout (all variants), Mysterious Serum, and X-cell are usable now. I have removed the END/HP/Rad component of these items. This was done to let melee players be able to use these drugs as they are part of their normal playstyle, just had to make them YOLO friendly. 
• Ballistic Weave capability added to 47 new hats where it would make sense. The original game had 4, so now you have 51 hats to choose from. I did this because it never made sense why a Battered fedora could take a weave but a Dirty fedora could not, same +1 Luck to both. Always felt like an oversight. 
  

---Warning--- I think chem addiction still lowers END in Version 2. That will be fixed in Version 3. 

9/2/2021 - Version 3 is 90% done. I'm trying to add an item to the game much like my Vault-Tec Blood Tester. This item will fix your health if the script doesn't run and you heal to full on a level up. Right now the only way to fix it is to either reload an old save or use a console command to fix it. If I can replicate the VTBT and make a "True Health Restoration Device" then it'll be in Version 3. I think I've removed all healing/rad removal/limb fixing from the game. As well as making all food/drinks usable by removing the YOLO breaking effects they used to have.

UPDATE #3:

Version 3 of this mod is in beta. I still need to do a full playthrough so I can test it for errors and see if I missed anything. 

• This version includes everything in Version 2
• Chem addiction END debuff removed. 
• If you talk to the Institute Dr he will no longer fade to black and heal you of all issues. The Dr will just small talk until he gets bored and starts ignoring you.  Be warned, the Diamond City doctor will still heal you if you keep selecting "heal me" in the dialog options. That's like 3 intentional dialog choices deep so if you do that it's on you.
• All healing items should be disabled, just in case of accidental use. (Stimpacks, Radaway, X111 Compound, etc)
  

• All END buffs removed from food/drinks. Some items only had END buffs so they are now just for show. 
• SCAV! #5 no longer modified END based on caps
• Astoundingly Awesome Tales #6 no longer regens health. 
• END boosting V88 bike disabled. I struggled with this one, wasn't sure I wanted to disable it. However, after seeing how confusing Jon's FO4 YOLO run is with the constant up/down to END I wanted to remove everything that could alter Endurance.
• Items that remove addiction or disease should be disabled. Items like Refreshing Beverage are usable, they just don't do anything other than restore a lot of thirst. So some items that were not usable are now a viable option since they won't break your YOLO run. 
  

10/4/2021 - Version 3 Beta is live. I was not able to add the True Health Restoration Device mentioned above. It will take more time to figure out. For now I'm just going to do a playthrough and see if V3 has any errors. I changed a lot in V3 to remove all healing that could be accidentally triggered.

ATM the only way to fix a level up healing event error is console command "player.damagevalue health xxx", with xxx being the delta you need to get back down to true health (xxx = max health - true health). That will reduce your health from max health back down to the true health value. The mod is set to run a health restore after a level up, but sometimes the script just fails to run, and the level up actual heals you to full. 

I thought about trying to add an on screen display of your true health like the YOLO mod Jon is using does. After downloading that mod and looking at the scripts, no chance. JJ2198 is lightyears better at modding than I am. It's way over my head. I can change a few things in FO4Edit, do a bit of programing here and there but nothing like what JJ2198 did. 

If I could just find a way to disable that level up healing effect it would solve everything, but it'll take someone a lot smarter than me to figure it out.


Basic Details:

• Survival mode requires eating and drinking. As such all healing from food/water has been removed. Cooked food effects remain, such as the +25 Carry Weight buff from Grilled Radstag. Healing has also been removed from the Cannibal Perk, so corpses are on the menu! 
• Survival mod requires that you sleep. The HP/Limb healing you would normally get from sleeping has been removed. If you go to sleep injured you will wake up injured, even if you are well rested. Speaking of which...
• All Endurance buffs are removed from outfits and hats, Fortifying / Champion Legendary Armor, and Buffout/X-Cell/Mysterious Serum. Do not wear DIMA's chest piece rewards as it has +1 END and I was not able to remove that. Avoid any other END buffs I might have missed, but please submit a bug report so I can fix them. 
• Endurance debuffs are also removed. Such as the END debuff when you are hungry or when you are over-encumbered. While you do control when you are over-encumbered, it was too dangerous to leave in. If you were in a fire fight and you picked up a gun that over-encumbered you, you'd then have less HP than normal. If you were shot while over-encumbered you could die when you should still be alive. In the end I removed it because I do not want any game mechanics to modify Endurance or alter hit points in any way.
• Infection.... The Infection disease is the reason I made this mod. I have been playing FO4 Survival on YOLO rules for years, but it's always been with all diseases removed, just to get rid of Infection. And that was far too easy. So this mod removes Infection but leaves the rest of the diseases in the game. 
• There are 2 places I know of that force a Rad scrub: Mass Fusion's basement and the Mechanist's basement. In those locations use a Vault-Tec Blood Tester (VTBT) before the Rad scrub. Using this one time use item will display your current radiation on the screen. Write down your Radiation level and take the Rad scrub. After that go stand in Radiation and use the VTBTs to monitor your Rads until you reach the correct radiation level. These VTBTs are crafted at the Chemistry Station for free. 
• When you level up FO4 runs a scripted event that heals you. For years I've dealt with that by keeping track of my HP manually, a True Health counter. I wanted this mod to handle that. To do that I studied the Horizon Level-Up Healing Removal mod. From that mod I learned how scripts work and wrote a lot of math to correctly factor in the natural HP addition you get at each level up (based on your END) while also tracking any HP lost due to your current radiation level. So if you have END 5, are at 40/200 hp, and level up you will have 45/205 hp. The correct level up HP is added to current AND max HP. 
  

*Caution on #7. This script is 95% reliable. There are just some times when the game will not run the script correctly. I can't figure out why. When it fails a level up will fully heal you. My recommendation is to save the game when you know you are about to level up. Example: I turned in a quest, leveled up, mod failed to run, I was fully healed. I reloaded a save RIGHT BEFORE, turned in the same quest, leveled up, the mod worked fine. Plan accordingly. (This part of the MATN YOLO mod is a "nice to have" but not really required. You could always keep a True Health Counter like Jon did for his previous YOLO runs.)


Misc info and Tips:

• Before you take any damage your HP might not look right when you level up. To fix that reload a save. Or exit the game and reload using the built in exit save. Your HP will be correct. Once you take any damage at all the level up HP should be correct. 
• Healing items are still in the game since they are in your control. Don't accidently hit the Radaway/Stimpack buttons when on the Pipboy's STAT screen. 
• Word of caution in the Institute. If you talk with the Doctor in the green coat he will automatically heal your HP, remove all radiation, and probably cure all diseases.  Avoid that Doctor. 
• Since healing is removed from the Cannibal perk there is no reason to take Rank 3 of it. Rank 1 lets you eat delicious humans, Rank 2 adds Ghouls and Super Mutants to the menu. Rank 3 was just more healing from eating bodies. Since healing is removed there is no difference in Ranks 2 & 3. 
• Some perks should be avoided, like Solar Powered. It gives you an END buff. I did not remove them from the game, that's on you to avoid them. If you are attempting a YOLO run you should have a high degree of self control so I believe in you not to be a dirty cheater. 
• In the Boston Mayoral Shelter/Bunker do not pick up the Astoundingly Awesome Tales #6 magazine, it will give you healing over time and ruin your YOLO run. 
• I've removed the blurry vision from a crippled head, and the loud heartbeat from low HP. Main reason I removed them is because they negatively impact the video viewing experience for an audience. If you are uploading a series to YouTube or streaming your run on Twitch for example.  
• Crippled limbs do still have their negative effects. If you have a crippled arm your aim will sway. If you have a crippled leg you will be very, very slow. So slow you might as well just start a new run and make Adamantium Skeleton a high priority. 
• If you are over-encumbered you have about 45 seconds before you take damage. Get a knife, move the camera to 3rd person, and stab the air. You will do a quick little stab-lunge forward. Time it right and you can keep stabbing the air to move faster while over-encumbered. It's like the fight Bart and Lisa Simpson had, S6E8 "Lisa on Ice". 
• Remember ---- If you are working on your Power Armor all of the power armor pieces are put in YOUR inventory. This can over-encumber you. You will take damage from that. Plan ahead. 
• If you have 300 rads that's 300 out of 1000, or 30%. That means 30% of your health bar is now red from Radiation. Every 10 Rads is 1% of your health lost, and that red radiation bar will scale bigger since it's a percentage of your total health. Plan out your run so you do radiation heavy areas after you have lost some HP to make room for the red. 
• If you have any tips post them in this Mod's comment section. 
  

Load Order:

Since this is basically a new difficulty mode put this mod last so it has highest priority in your mod list.

Patches:

I do not have enough time nor enough knowledge to make patches for this mod to work with any other conflicting mod. As the author of this mod I recommend getting rid of those other conflicting mods. 



Conclusion: 

The Good News is that if I can make a mod like this anyone can!  I went from zero understanding of mods to essentially making a new difficulty mode in only 8 days. I highly encourage anyone that wants to make a mod to get in the forums and ask questions, watch youtube tutorials. There are a lot of knowledgeable folks here that are willing to help you. Download a mod and dig into it. Learn how they did it, then make your own using theirs as a tutorial. 


I want to thank Jon at Many A True Nerd for creating this amazing rule set. I can't play Fallout 4 any other way now. 

I want to thank the Horizon mod creator Zawinul. I've never played the Horizon mod but it sounds brutal and just wonderful. 

I want to give a special thank you to Nexus member Yulliah. They helped me so much when I was struggling to learn how to add in the Vault-Tec Blood Tester.



Good luck