You will need to be well prepared.
Bethesda are making big changes to Fallout 4’s Survival Mode difficulty setting, which Steam players can now try out as a beta. The company has posted the full Survival Mode feature list, which include thirst, immunodeficiency, and tons of other changes.
One of the bigger changes is that you won’t be able to fast travel in Survival Mode, which will force you to walk from location to location. The mechanics for saving your game have also changed, as you will only be able to do so by sleeping in a bed for a minimum of one hour, instead of relying on the game to save automatically. Your character will do more damage to enemies, but they will also do more damage to you. Oh, and these enemies will not automatically show up on your compass either.
To make things even more difficult, you will have to keep hydrated and well-fed, else your character you will be affected with fatigue, which affects your Action Points. Bethesda notes that this was inspired by From Software’s Dark Souls series.
More specific changes are also made to Fallout 4’s survival Survival Mode. Different beds will limit how long you can rest for, while healing is a lot slower. There will be multiple illnesses that can hurt you, but there will be cures for them. RadAway will negatively affect your fatigue and your immunity, while crippled limbs will only heal when you either use a StimPak, or by sleeping.
Carry weight has been reduced, while being over this amount will slowly cripple your legs. Downed companions will return to the settlement rather than get up automatically, and finally the world will be repopulated with enemies and items at a much slower rate.
You can check out Bethesda’s full notes on the changes here. Survival Mode is Fallout 4 is currently available as a beta on Steam.