The player metabolism is made of 7 elements: Hunger, Thirst, Fatigue, Digestion, Alcohol, Warmth and Encumbrance.

Depending on their state, they affect more or less in a negative way the player stats.

1. Hunger

   Character naturally becomes hungry at a rate of 0.5 every 15 minutes (1 real minute).

   While sleeping, the rate is decreased by 0.25 (50%).

   To reduce hunger, the character must use a food packet, eat at a tavern or cast the spell Curing Hunger.

   The different stages of hunger, the time to reach them naturaly, and their effects are:

   Hunger	Stage	Time	Effects
   0 to 16			Removes all hunger penalties.
   16 to 48	Famished	8 hours
   48 to 96	Hungry	24 hours
   96 to 255	Starving	48 hours	Probability of 50% to increase by 1 a random primary stat penalty every 15 minutes.

2. Thirst

   Character naturally becomes thirsty at a rate of 0.5 every 15 minutes (1 real minute).

   The rate is increased by 1/12.8 ~= 0.08 (+15.6%) when the character warmth is at stage Hot.

   While sleeping, the rate is decreased by 0.25 (50%).

   To reduce thirst, the character must use a water flask, have a drink at a tavern or cast the spell Curing Thirst.

   The different stages of thirst, the time to reach them naturaly, and their effects are:

   Thirst	Stage	Time	Effects
   0 to 16			Removes all thirst penalties.
   16 to 32	Thirsty	8 hours
   32 to 56	Very Thirsty	16 hours
   56 to 255	Parched	28 hours	Probability of 50% to increase by 1 a random primary stat penalty every 15 minutes.

3. Fatigue

   Character naturally becomes tired at a rate of 0.5 every 15 minutes (1 real minute).

   The rate is increased by:

   • 1/12.8 ~= 0.08 (+15.6%) when the character warmth is at stage Hot.
   • 0.125 (+25%) when the encumbrance is at stage Burdened.

   While sleeping, the rate is null. To reduce fatigue, the character must sleep at an inn.

   The different stages of fatigue, the time to reach them naturaly, and their effects are:

   Fatigue	Stage	Time	Effects
   0 to 40			Removes all fatigue penalties.
   40 to 72	Weary	20 hours
   72 to 96	Tired	36 hours
   96 to 255	Very Tired	48 hours	Probability of 50% to increase by 1 a random primary stat penalty every 15 minutes.

4. Digestion

   Character naturally digests at a rate of -3 every 15 minutes (1 real minute).

   Stomach bloats when the character uses food packets, water flasks or eats at a tavern.

   If too much is absorbed, the character becomes Bloated:

   Digestion	Stage	Effects
   0 to 127		Removes the bloated penalty.
   128 to 255	Bloated	Increases the speed penalty by 4.

5. Inebriation

   Note: I didn't succeed to exactly map the algorithm with the human metabolism. I've tried to give a meaning to the variables, but it's still inconsistent.

   What seems correct:

   • Human body eliminates alcohol in blood at a rate of 10 to 15 mg/mL every hour. In the algorithm, the rate is 12 mg/mL (4*3).
   • Alcohol concentration in blood affects the character (see below).

   What seems inconsistent:

   • The alcohol concentration in intestine is reduced by the "digestion rate" and not by the amount of alcohol absorbed in blood.
   • The character becomes drunk when the alcohol concentration in blood reaches the stamina value, which could be 20 mg/mL. Legal limit for driving in France is around 80 mg/mL...

   // this algorithm is called every 15 minutes (1 real minute)
   if ((alcoholBloodConcentration != 0) || (alcoholIntestineConcentration != 0) {
     // intestine -> blood
     alcoholBloodConcentration += alcoholIntestineConcentration; (?)
     // blood -> out
     alcoholBloodConcentration -= 3;
     // if there's something to absorb
     if (alcoholIntestineConcentration != 0) {
       // alcohol digestion rate in intestine increases with time (?)
       alcoholDigestionRate ++;
       // digest partially alcohol in intestine
       alcoholIntestineConcentration -= digestionRate; (?)
       // if no more alcohol in intestine, stop absorption and digestion
       if (alcoholIntestineConcentration < 0) {
         alcoholIntestineConcentration = 0;
         alcoholDigestionRate = 0;
       }
     }
   }
   

   The different stages of inebriation and their effects are:

   Alcohol blood concentration	Stage	Effects
   0
   ]0; Sta]	Tipsy	Loss of coordination: bottom status screen randomly changes.
   ]Sta; 2*Sta]	Drunk	Loss of balance: movement is hampered (random moves). Banks and inns jobs are forbidden.
   [2*Sta; +∞[	Very Drunk	Loss of sight: random blackouts. Entering smithies, shops and taverns are forbidden.

   The character resistance to inebriation depends on its effective stamina.

   The inebriation effects stack.

   The character stealth is temporary reduced by its alcohol blood concentration.

   When the character drinks alcohol in tavern, half of it goes directly in blood too.

   Here are examples of alcohol concentration in blood after some drinks (with a stamina of 20):

   • 1:00 2 grogs (amount of 6)
   • 2:30 All alcohol eliminated
   • 3:00 2 grogs and 2 wine (amount of 10)
   • 3:45 Character drunk
   • 6:00 All alcohol eliminated
   • 7:00 3 grogs (amount of 9)
   • 8:45 4 grogs (amount of 12)
   • 9:00 Character drunk
   • 9:45 Character very drunk
   • 13:30 All alcohol eliminated

   

6. Warmth

   The warmth perceived by the character depends on two factors: the weather temperature, the clothes worn and the character location. It's computed like this:

   • Each article of clothing worn adds to the character's protection.
   • If the protection isn't null, an additional protection of 10°F (5.6°C) is given.
   • The resulting value is bounded by 80°F (44.4°C), then increased by the weather temperature.
   • Warmth in buildings is always 72°F (22.2°C) regardless of the weather and the clothes the character is wearing.

   The different stages of warmth and their effects are:

   Warmth		Stage	Effects
   < 48°F	< 8.9°C	Cold!	Increases the speed penalty by 5. Increases the skill penalty by 5. Character loses clarity. Removes all Hot penalties.
   48°F to 64°F	8.9°C to 17.8°C	Cool	Removes all Hot and Cold penalties.
   64°F to 79°F	17.8°C to 26.1°C
   79°F to 99°F	26.1°C to 37.2°C	Warm
   > 99°F	> 37.2°C	Hot!	Increases the thirst rate by 1/12.8 ~= 0.08 (+15.6%). Increases the fatigue rate by 1/12.8 ~= 0.08 (+15.6%). Character loses clarity. Removes all Cold penalties.

7. Encumbrance

   The total weight is calculated by adding the weight of all carried items. This includes:

   • Water Flasks and Food Packets (1 unit for each pack of 16)
   • Gold, Silver and Copper coins (1 unit for each pack of 16)
   • Gems and Jewelry (1 unit for each pack of 16)
   • Items in inventory, equiped or worn (variable weight)

   The character can carry a base weight of 224 units. The encumbrance is defined by the following formula:

   • encumbrance = carried weight - (effective strength + 224)

   The different stages of encumbrance and their effects are:

   Encumbrance	Stage	Effects
   < 0		Removes all encumbrance penalties.
   [0; 16[	Burdened	Increases the fatigue rate by 0.125 (+25%). Removes the Encumbered and Immobilized speed penalty penalties.
   [16; 33[	Encumbered	Increases the speed penalty by 8. Removes the Immobilized speed penalty penalty.
   [33; +oo[	Immobilized!	Increases the speed penalty by 50.