Survival Mechanics

Preview of all survival systems needed to stay alive, including Needs, Health & Injuries, Status Effects, Environmental Factors, Nutrition, Mental Health, Disease Progression, and Sleep Deprivation.

Core Needs

The player has four primary needs that must be constantly managed. Each drains over time and can cause death if depleted.

Hunger

• Starting Value: 85/100
• Max: 100 (0 = Starving)
• Drain Rate: 0.25/hour base
  • Day: 0.88× (slower at night)
  • Perk Modifiers:
    • efficient_eater: 0.80× drain
    • big_appetite: 1.20× drain
• Critical Effects:
  • < 15: +1.5 fatigue/hour
  • < 25: +0.15 morale drain/hour
  • < 35: -0.35 condition/hour
  • ≤ 0: -1 HP/hour, death from starvation
• Restoration: Eating food
  • Cooked Food: High restoration, +morale
  • Canned Food: Moderate restoration, 8% chance hygiene loss
  • Raw/Foraged: Varying restoration, 20% base food poisoning chance

Thirst

• Starting Value: 85/100
• Max: 100 (0 = Dehydrated)
• Drain Rate: 0.25/hour base
  • Day: 1.12× (faster when hot)
  • Perk Modifiers:
    • water_conservator: 0.80× drain
    • dehydrates_quickly: 1.20× drain
• Critical Effects:
  • < 15: +2.5 fatigue/hour
  • < 25: +0.20 morale drain/hour
  • < 35: -0.35 condition/hour
  • ≤ 0: -2 HP/hour, death from dehydration
• Restoration: Drinking water
  • Potable Water: Boiled or purified (safe)
  • Raw Water: Risk of Dysentery/Malaria (15% if contaminated, 3% if stagnant)
  • Disinfectant: Can purify water

Warmth

• Starting Value: 70/100
• Max: 100 (0 = Freezing)
• Drain Rate: Base 0.35/hour × environmental multipliers
  • Weather Factor: 1.0 + (wind×0.10) + (precip×0.08) + (cold°C×0.05)
  • Night: 1.18× (colder at night)
  • Storm at Dawn: 1.08×
  • Shelter Quality: Reduces drain by up to 45% (0.55-0.90× multiplier)
  • House/Building: Significant reduction based on completion/insulation
  • Sleeping Bag (during rest): 0.70× drain
  • Clothing Insulation: Multiplicative reduction
  • Perk Modifiers:
    • cold_adapted: 0.70× drain
    • cold_sensitive: 1.30× drain
  • Achievement Bonuses: Cold resistance reduces drain
• Critical Effects:
  • < 25: +0.20 morale drain/hour
  • ≤ 0: -1 HP/hour, death by freezing
• Restoration:
  • Fire: +25 warmth/hour (must be standing on fire spot)
  • Complete House: Passive warmth bonus when inside

Fatigue

• Starting Value: 10/100
• Max: 100 (100 = Exhausted)
• Accumulation: Increases with physical actions
  • Activity-specific values (see FAT constants in code)
  • Move: +0.25 (×2 if running, reduced by agility)
  • Crafting: +0.25-0.80 depending on item
  • Hunting/Fishing: +0.75
  • Heavy load: Additional drain based on encumbrance
  • Low hunger (<15): +1.5/hour
  • Low thirst (<15): +2.5/hour
  • Fracture: +1.5/move
• Sleep Debt: If no sleep for 36 hours (24h with light_sleeper perk), fatigue snaps to 100
• Effects:
  • ≥ 95: 30% chance of microsleep (lose 0.5 hour), 20% injury chance
  • ≥ 100: Cannot perform actions (blocked)
  • > 75: +0.15 morale drain/hour
  • > 80: 22% chance of disorientation when moving
• Restoration:
  • Sleep: -40 fatigue, heals +HP
  • Rest: -20 fatigue, heals +HP

Morale

• Starting Value: 70/100
• Max: 100 (0 = Broken)
• Drain Rate: 0.10/hour base + penalty modifiers
  • Hunger < 25: +0.15/hour
  • Thirst < 25: +0.20/hour
  • Warmth < 25: +0.20/hour
  • Fatigue > 75: +0.15/hour
  • Injury > 0: +0.08/hour
  • Night without fire: +0.08/hour
  • House Bonus: Reduced loss + passive morale gain when inside
  • Perk Modifiers:
    • optimist: 0.75× drain
    • pessimist: 1.25× drain
• Effects: Low morale reduces efficiency, can cause disorientation (+22% when <30)
• Restoration:
  • Good food (+morale)
    • Canned Food: +6.0 Mental
    • Cooked Food: +2.5 Mental
  • Comfort/shelter
  • Sleep/rest
    • Sleep: +8.0 Mental (net)
    • Rest: +5.0 Mental (net)
  • Reading: +12.0 Mental (requires Old Book)
  • Painkillers: +5.0 Mental
  • Success in actions
  • Companion: +0.5/hour
  • Random events: ±2-2.5 morale (3% chance/hour)

Health & Injuries

Health (HP)

• Starting Value: 100/100
• Max HP Calculation: Base 90-100 + (condition×0.1) + endurance bonus + achievement bonuses
  • Condition-based: 90 + round(condition×0.1)
  • Endurance Attribute: +(endurance-3)×5
  • Achievement Bonuses: Various permanents perks
• Damage Sources:
  • Combat, falls, starvation, dehydration, freezing
  • Disease, poison, bleeding, infection
  • Injuries, fractures
• Healing:
  • Natural (Sleep): +2 HP base + house bonus
  • Natural (Rest): +2 HP base
  • Medicine: Heals +1-10 HP (Intelligence-based)
  • Bandage: Stops bleeding, heals broken limbs (Splint required for Fracture)
• Death: HP ≤ 0 ends the game

Condition

• Starting Value: 75/100
• Range: 25-110
• Decay: -0.35/hour when hunger < 35 OR thirst < 35
• Recovery: +0.5/hour during rest/sleep (+ endurance bonus)
  • Complete House Bonus: +0.3/hour additional
• Effect: Affects max HP calculation

Status Effects

Basic Status Effects

Bleeding

• Cause: Injuries, combat, accidents
• Effect: -HP over time (0.9 + bleeding×0.6, max 4.5 HP/hour)
• Morale Impact: -0.6/hour
• Natural Decay: -0.25 bleeding/hour
• Treatment: Bandage or Tourniquet stops bleeding
• Death: Can bleed to death if HP reaches 0

Fracture (Broken Bones)

• Cause: Falls, combat, accidents
• Effect:
  • Limits movement/actions
  • +1.5 fatigue per move
  • 12% chance of -0.8 HP/hour
  • -0.4 morale/hour (12% chance)
• Treatment: Splint (Wood + Cordage)
• Death: Untreated fractures can be fatal

Infection (Wound Infection)

• Cause:
  • Injuries in wet conditions (precip > 1.5)
  • Injuries when warmth < 45
  • Base chance: 8% + injury×0.2% per hour
• Effect:
  • -0.4 HP/hour
  • -0.5 thirst/hour
  • -0.3 hunger/hour
• Treatment: Antibiotics (instant cure) or rest in clean house (chance-based recovery)
• Death: Can die from infection

Skin Infection

• Cause: Low hygiene
• Effect:
  • -0.2 HP every 5 hours
  • -0.3 morale every 5 hours
• Recovery: 20% chance/5 hours when hygiene > 65
• Death: Can be fatal if severe

Advanced Disease System

Stomach Bug (Food Poisoning)

• Cause: Raw/bad food (20% base), contaminated water
• Effect:
  • Severe dehydration: -5.0 thirst/hour
  • Severe appetite loss: -4.0 hunger/hour
  • HP loss: -2.5/hour
  • Morale loss: -2.0/hour
  • Vomiting messages every 4 hours
• Recovery: 28% chance during rest/sleep
• Death: Can die from illness if HP depletes

Disease Progression (Advanced System)

• State Variables:
  • disease: null or disease type
  • diseaseProgress: 0-100
  • infectionStage: 0-3 (progressive infection)
  • sepsis: boolean (critical infection state)

Environmental Extremes

Frostbite

• State Variable: frostbite (0-100)
• Cause: Extended exposure to extreme cold (warmth ≤ 0)
• Effects: Untreated frostbite can cause death
• Treatment: Warming, medical attention

Heat Stroke

• State Variable: heatStroke (0-100)
• Cause: Excessive heat, dehydration in hot biomes
• Effects: Untreated heat stroke can cause death
• Treatment: Cooling, hydration

Environmental Factors

Warmth System

• Sources: Clothing, Fire, Shelter, Buildings
• Loss Factors:
  • Cold biomes
  • Night time
  • Rain/wetness
  • Wind
  • Precipitation
• Protection:
  • Clothing: Insulation stats reduce warmth drain
  • Shelter: Up to 45% warmth drain reduction
  • House: Major reduction + passive warmth gain (if complete)
  • Fire: +25/hour when standing on fire spot (lasts 18 hours max)

Hygiene

• Starting Value: 78/100
• Drain Rate: 0.04/hour base + environmental/activity penalties
  • Precipitation: +(precip×0.6)/hour
  • Low warmth: +(100-warmth)/120 per hour
  • Activities:
    • gather/hunt/fish/collect_water: +0.32/hour
• Effects:
  • Low hygiene: 6% chance of infection per hour (when <threshold)
  • Increases risk of skin infection
• Restoration:
  • Washing: +4 hygiene
  • Clean water
  • Avoid dirty/swamp activities

Load/Encumbrance

• Weight Cap: Base 100 kg (modified by perks, attributes, items)
• Over-Encumbrance (>60% of cap):
  • Fatigue: +overEffort×0.08/hour
  • Hunger: -overEffort×0.02/hour
  • Thirst: -overEffort×0.03/hour
  • Injury Risk: 10% chance of +1 injury if overEffort > 20

Nutrition System

• State Variables:
  • protein: 50/100 (starting)
  • carbs: 50/100 (starting)
  • fats: 50/100 (starting)
  • vitaminC: 50/100 (starting)
• Effects: Different foods provide varying nutrition profiles
• Impact: Affects overall health, condition, and recovery rates
• Note: Full mechanics integrated into food consumption system

Mental Health System

Mental Health Stats

• Mental Health: 70/100 (starting)
• Loneliness: 0/100 (starting)
• Trauma: 0/100 (starting)
• Cabin Fever: 0/100 (starting)

Effects

• Low mental health impacts morale, decision-making, and survival effectiveness
• Loneliness: Increases when isolated for extended periods
  • Mitigation: Companion presence, NPC interactions
• Trauma: Increases from violent encounters, deaths
• Cabin Fever: Increases from extended time indoors without variety

Sleep Deprivation System

Sleep Debt

• Threshold: Must sleep at least once every 36 hours (or 24h with light_sleeper perk)
• Penalty: Fatigue snaps to 100 if threshold exceeded
• State Variables:
  • sleepDeprivationLevel: 0-100
  • hallucinating: boolean
  • lastSleepH: Hour of last sleep

Hallucinations

• Occur at high sleep deprivation levels
• Can cause disorientation, false perceptions, increased danger

Death Conditions

The game ends when HP ≤ 0, caused by:

1. Starvation: Hunger ≤ 0
2. Dehydration: Thirst ≤ 0
3. Freezing: Warmth ≤ 0
4. Bleeding Out: Bleeding damage
5. Injuries: Untreated wounds
6. Infection: Wound or skin infection
7. Illness: Stomach bug/disease
8. Fractures: Untreated broken bones
9. Sepsis: Critical infection state (advanced)

Constants Reference

Drain Rates (per hour)

• HUNGER_DRAIN: 0.25
• THIRST_DRAIN: 0.25
• WARMTH_DRAIN_BASE: 0.35 (before modifiers)
• HYGIENE_DRAIN: 0.04 (before modifiers)

Recovery Values

• HYGIENE_WASH_GAIN: +4
• FIRE_WARMTH_PER_HOUR: +25
• FIRE_MAX_HOURS: 18
• HYGIENE_LOW_INFECTION_P: 6% (when hygiene low)
• CONDITION_BASE: 75

Sleep System

• Sleep debt threshold: 36 hours (24h with light_sleeper)
• Fatigue reset: -40 (sleep), -20 (rest)

Perk Modifiers

Positive perks reduce drains, negative perks increase them:

Positive Perks:

• efficient_eater: 0.80× hunger drain
• water_conservator: 0.80× thirst drain
• cold_adapted: 0.70× warmth drain
• optimist: 0.75× morale drain

Negative Perks:

• big_appetite: 1.20× hunger drain
• dehydrates_quickly: 1.20× thirst drain
• cold_sensitive: 1.30× warmth drain
• pessimist: 1.25× morale drain
• light_sleeper: Sleep required every 24h (vs 36h)