Needs refers to the variety of factors that affect Albert West's overall health. There are several different needs to monitor in Subterrain. Most needs are affected by the difficulty that is being played. The needs will be colored differently depending on the urgency of the need to be satisfied at a particular time. (Green: Not urgent; Orange: Urgent; Red: Very urgent)
The status HUD in the game. Note the different colors to represent how urgent each need is.
HP
West's HP is a measure of his remaining life; once it reaches 0, game over (note that the game rounds down, so HP between 1 and 0 will be shown as 0). The primary thing that will decrease West's HP is mutant attacks, but he can also take damage from a lack of oxygen, stepping on the radioactive waste in the northern part of Central Control, a low body condition, and potentially other factors.
If West's body condition is high enough (about 85 and higher), he will very slowly recover HP over time. West can also apply a medical kit to restore a portion of his HP over a shorter time. HP is one of the few needs that has no colored indicator, nor does West make a note of it at any point. It is represented by the curved bar to the left side of the circle.
Contamination
West's contamination is a measure of how infected he is. His contamination is shown as red dots in the bottom left circular HUD. The higher the contamination, the more red dots that there will be in the circular HUD. To decrease contamination, eat a decontamination pill. Suits that West wears can resist some contamination that he receives. West can be contaminated by:
- A mutant hitting him (guaranteed)
- Eating rotten food (guaranteed)
- Opening the wrong Better Bar (guaranteed)
- Eating food that may be contaminated (chance)
- Drinking water from a tap (chance)
Contamination decreases West's body condition in an almost linear fashion, maxing out at 100 contamination (with body condition at 33). In addition, contamination very gradually multiplies. As examples, 0 contamination will always be 0 without any other factors (see above); 10 contamination will increase by 1 very slowly (approximately 1 per day); and 90 contamination will increase by 1 slowly (approximately 1 per hour). These numbers may not be accurate; they are simply to illustrate the mechanic.
Body Condition
West's body condition is a summary of his overall health, and many factors can decrease it. West's natural health recovery is directly linked to his body condition: at 100 body condition, West will slowly recover lost health; however, as his body condition lowers, so will his regeneration rate. If his body condition is low enough (below about 85), West will even lose health as time passes.
West's body condition will decrease if his contamination, fatigue, hunger, or thirst get too high. Body condition is represented by the texture inside the circle and does not use the normal "rules of importance" that most other needs do. Instead, as his body condition worsens, the texture becomes more browned and possibly even red.
Note that any "minimum body condition" values given on this page assume only the titled factor being involved.
Fatigue
Fatigue is how tired West is. It affects his maximum stamina, as well as his running speed. To decrease fatigue, West needs to sleep in a bed. He can't sleep in anything but a bed, and he won't sleep if any enemies are around (including cocoons). Once West's fatigue hits 75, his max stamina will drop to 33 (minimum 25 at 100 fatigue) and his body condition and max stamina will gradually decline until his fatigue is restored to below 75. His max stamina and body condition will slowly recover to their normal values after his fatigue is below 75.
If West's fatigue is left at 100 for too long (at least one day; still needs testing), his health will begin to quickly drop (losing 1 health about every 3 minutes), regardless of any other needs. It takes about 3 hours and 35 minutes to go from 100 fatigue to 0 without waking, which averages to about 1 fatigue for 2.15 minutes of rest.
Thirst
Thirst is how thirsty West is. Thirst has little impact on West, but at about 70 Thirst, West's running speed will decrease, and his body condition will slowly decrease by up to 34 once thirst nears 100. To satisfy West's thirst, you can drink any drinks that can be found in MPO. You can also drink from a faucet, but it comes with a chance of heavy contamination.
Hunger
Hunger is how hungry West is. To decrease hunger, you can eat any food that can be found in MPO. If West's hunger reaches 90, his running speed will lower and his body condition will quickly decline by up to 34. Note that 66 body condition is low enough for West's health to deteriorate over time.
Bathroom
After consuming a drink or food, West will occasionally have a need to urinate or defecate. It starts out as a slight need, and then it turns into a serious need. The only way to alleviate this need is to use a toilet (a urinal also works for urinating, but not for defecating). Ignoring these needs is not inherently fatal or even dangerous; however, if West is already suffering from several other problems, like high contamination and hunger, a need for the bathroom could tip him over the edge.
Oxygen and Heat
West will need to be able to breathe, so an oxygen canister is needed where there is no Oxygen. If West runs out of Oxygen, his health will start to rapidly drop after a short time.
West will also need to be able to keep warm, so a thermal canister is required where it is too cold for him to survive normally. If West cannot stay warm, he will become crippled (removing his ability to run and dodge) and his thirst will increase significantly faster (at a rate of 1 Thirst per 2 in-game minutes).