When you are afflicted with an illness, a message will appear onscreen. Eating uncooked meat, drinking unpurified water, taking damage from disease-ridden sources, such as ghouls and bugs, or using harmful Chems all put your body at increased risk for various ill effects.

A comprised immune system and a few questionable decisions can end up getting you killed.

The amount of Fatigue you've accumulated is displayed in red on your AP bar. The more Fatigue you've built up, the less AP you'll have for other actions.

Fatigue works like radiation but affects your Action Points (AP) rather than your Hit Points (HP).

Going for extended periods of time without food, water, or sleep will begin to adversely affect your health, hurting your SPECIAL stats, adding to your Fatigue (see 'Fatigue' below), lowering your immunity (see 'Sickness' below), and eventually even dealing physical damage to you.

You must stay hydrated, fed, and rested to remain combat-ready.

You'll find it difficult to survive without taking proper care of yourself.

You can check your current Adrenaline rank at any time in the Perks section on the Stat tab in your Pip-Boy. Sleeping for more than an hour, however, will cause your Adrenaline rank to lower. The higher your Adrenaline rank, the higher the damage bonus. Unlike other perks, the only way to increase your rank of the Adrenaline perk is by getting kills (hostile or otherwise).

Survival automatically grants the Adrenaline perk, which provides a bonus to your damage output.

As well, the distance at which locations of interest will appear has been significantly shortened.

Be sure to keep your eyes peeled, as enemies will no longer appear on your compass.

Heavier items such as fusion cores, rockets, and mini-nukes can really drag you down.

Bullets and shells now all have a small amount of weight, which varies by caliber.

If you wish to be somewhere, you'll have to physically travel there. You can increase the damage you deal even further with 'Adrenaline' (see below). You now deal, but also take, more damage. To save your game, you'll need to find a bed and sleep for at least an hour.

The following is a list of changes experienced in Survival Mode:

Survival mode mods fallout 4