In-Game Formula

These are some of the equations that affect various role playing game parameters in some Castlevania titles, particularly the metroidvania genre.
==Castlevania: Circle of the Moon==
===Damage calculation===
====Attacking enemies====
To calculate damage inflicted to enemies, we need to calculate the power of the attack.
*If it is a physical attack (whip attack, slide or tackle), then:
::Power = STR + DSS enhanced STR
*If it is with a sub-weapon or Item Crash attack, then:
::Power = STR × STR rate
*If it is a DSS attack, then:
::Power = STR + DSS enhanced STR
::Power = Power × DSS power
::(Example: Diana + Cockatrice combination)
*If it is a DSS attack with a constant modifier, then:
::Power = DSS power
::(Example: Diana + Salamander combination)
*Damage inflicted to an enemy is:
::Damage = (Power × Power) / (10x Enemy Defense)
*If the enemy is resistant to the element:
::Damage = Damage / 2
*If calculated damage is less than 1, then:
::Damage = 1
====Damage taken from enemies====
*The power from enemies attack is:
::Power = Enemy STR × Attack modifier
::Where in most cases, body contact has an attack modifier equal to 1.
*Damage received from an enemy is:
::Damage = (Power × Power) / (10x Defense)
*If Nathan is frozen, then:
::Damage = Damage × 4
*If calculated damage is less than 1, then:
::Damage = 1
===Experience growth===
*Total required experience to reach certain level is
::EXP = floor (0.3 × (Level)⁴ + 1.8 × (Level)³ + 3.3 × (Level)² + 0.6 × (Level-1)² + 184.8 × Level - 0.6)
==Castlevania: Harmony of Dissonance==
===Rare Ghost appearance chance===
The base chance of the Rare Ghost appearing is 1/64 (about 1.56%). Luck increases the chances of its appearance (this is the only effect that Luck has in Harmony of Dissonance).
The first 79 points of Luck do nothing. Starting at 80, every 10 points of Luck adds an extra 1/64 chance roll.
So, the chance the Rare Ghost will appear at a given Luck stat can be calculated as follows, assuming the player has at least 70 Luck:
::Chance = 1 - (1 - 1/64)^(1 + (LCK-70)/10)
::(Example: 0 Luck is a 1.56% chance, 80 is a 3.10% chance, 90 is a 4.61% chance, etc.)
However, note that the Rare Ghost will only appear if the player enters the room on a frame number that is divisible by 4. So, if the player isn't able to enter the room consistently on valid frames, they can effectively consider the real chance of it appearing to be a quarter of the percentages shown above.
===Drop rate===
====Item drop rate====
*If Rare Ring isn't equipped:
::Both common and rare item drop chances can be out of 1,024, so 64 is a 6.25% chance, and 8 is a 0.78% chance for example.
*If Rare Ring is equipped:
::For the common drop the Rare Ring effectively increases the chance by +32 (3.12%).
::For the rare drop the Rare Ring effectively increases the chance by +16 (1.56%).
==Castlevania: Aria of Sorrow==
===Damage calculation===
====Attacking enemies====
Note that in this section, stone, poison, and curse are not considered as an element. An attack is considered effective if at least one of the element is effective. An attack is resisted if the attack has at least one element, all element beside Sword element is resisted, or if the attack only has Sword element, it is resisted.
*If jump kick:
::Power = STR × 1/2
*If slide:
::Power = STR × 15/16
*If Weapon or hand combat:
::Power = ATK
*If Bullet Soul:
::Power = (STR +60)/160 × AP
*If Guardian Soul:
::Power = (Soul AP rate × INT) + Soul AP
*If Hard Mode:
::Power = Power × 4/5
*If weapon has half damage effect (such as Handgun):
::Power = Power/2
*If enemy is being petrified (enemy is weak against stone, and has not been petrified yet):
::Power = 0
::Skip other status effect
*If enemy is poisoned:
::Enemy DEF = 0
*If enemy is vulnerable to curse and is attacked with curse type attack:
::Power = Power + Enemy HP/4
*If enemy is vulnerable to HP/MP swap, and has not been swapped yet:
::Swap HP and MP
*If the only effective element is Sword element:
::Power = Power + Power/4
*If at least one element beside Sword element is effective:
::Power = Power × 2
*If the attack is resisted:
::Power = Power - Power/2
*Damage Formula:
::Damage = (Power - Enemy DEF/2) × (256 - Enemy DEF)/256
*If calculated damage is less than 1:
::Damage = 1
*If enemy is petrified
::Damage = Damage × 2
====Damage taken from enemies====
*If it is an enemy attack:
::Power = Enemy STR × Attack modifier
*If it is spike damage:
::Power = (3 × (DEF - CON/2)) / 4 (DEF is calculated before Basilisk's soul bonus)
::Power = Power + Max HP/16
*If it is damage from the moving floor trap (like the one in Study):
::Power = (3 × (DEF - CON/2)) / 4 (DEF is calculated before Basilisk's soul bonus)
::Power = (Power + Max HP/16) / 3
*Damage formula (Normal Mode):
::Damage = 2x Power - DEF
*Damage formula (Hard Mode):
::Damage = (3 × (DEF - CON/2)) / 4 (DEF is calculated before Basilisk's soul bonus)
::Damage = (Damage + Max HP/16) / 2
::Damage = (Damage + 5x Power - 2x DEF) / 2
*If petrified, then:
::Damage = Damage × 2
*If strong against the element:
::Damage = Damage / 2
===Status modifier===
====Poison====
*Without Zombie soul equipped:
::STR = STR/4
::CON = CON/4
::INT = INT/4
*With Zombie soul equipped:
::STR = STR + ((STR/8) × 3)
::CON = (CON/8) × 11
::INT = (INT/8) × 11
*Poisoned Enemy
::STR = STR - STR/4
::DEF = 0
===Drop rate===
====Soul drop rate====
The formula will not be executed in Julius Mode or if the rarity of the soul is 0. Note that souls with 100% chance are gathered through event.
*If it is Normal Mode:
::Numerator of the chance = 6
*If it is Hard Mode:
::Numerator of the chance = 7
*If the soul has been captured previously:
::Numerator of the chance = 3
*If Soul Eater Ring is equipped:
::Numerator of the chance = Numerator + 8
*Rarity = (Soul Rarity x8) + 32 - (LCK/16)
::If Rarity is less than 16, set Rarity = 16
*Chance of getting enemy's soul
::Numerator of the chance = Numerator/Rarity
====Item drop rate====
The formula is calculated if the soul from previous calculation isn't acquired. Julius Mode skip this.
*If Rare Ring isn't equipped:
::Numerator of the chance of a common drop = 3/4
::Numerator of the chance of a rare drop = 1/4
*If Rare Ring is equipped:
::Numerator of the chance of a common drop = 5/8
::Numerator of the chance of a rare drop = 3/8
*If enemy has no item on the selected (either common or rare) slot:
::No item dropped
*Item rarity
::Rarity = drop rarity (depends on the slot)
::Rarity = (Rarity x4) + 16 - (LCK/16)
::If Rarity is less than 16, set Rarity = 16
*If Rare Ring isn't equipped
::Numerator of the chance = 4/Rarity
*If Rare Ring is equipped
::Numerator of the chance = 8/rarity
====Gold drop rate====
The formula is calculated if Soma hasn't got anything from previous steps. Julius Mode skip this.
*If enemy doesn't have any dropped item:
::No Gold dropped
*If Gold Ring isn't equipped:
::Chance = 1/128
::Chance of getting $1, $10, $50, and $100 is equal (1/4 Chance).
*If Gold Ring is equipped:
::Chance = 1/16
::Chance of getting $100, $500, $1000, and $2000 is equal (1/4 Chance).
====Heart drop rate====
The formula is calculated if Soma hasn't got anything from previous steps. Julius Mode skip this.
*If enemy doesn't have any dropped item:
::No Heart dropped
*If Heart Pendant isn't equipped:
::Chance = 1/128
*If Heart Pendant is equipped:
::Chance = 1/16
*Chance of getting heart:
::Chance of getting a small heart is 3/4 Chance
::Chance of getting a large heart is 1/4 Chance
===Experience growth===
*Total required experience to reach certain level (beyond level 1) is
::EXP = Level × (Level + 1) × ((3x Level) + 8)
::or
::EXP = 3 × (Level)³ + 11 × (Level)² + 8 × Level
*As a result, starting a new game over a completed save file will let Soma start with 22 EXP.
==Castlevania: Dawn of Sorrow==
===Damage calculation===
====Attacking enemies====
In Dawn of Sorrow, weaknesses increase damage the enemy takes if the enemy is weak to any of the elements of the attack.
*If at least one of those elements is magical (Fire/Ice/Lightning/Dark/Holy), the multiplier is 1.5× damage.
*Otherwise, if it is just physical or status effect weaknesses (Strike/Stab/Slash/Poison/Curse/Stone), the multiplier is 1.25×. Resistances halve damage the enemy takes only if the enemy resists ALL elements of the attack (only counting the base 8 elements, Poison/Curse/Stone don't necessarily have to be resisted too). Unlike Portrait of Ruin and Order of Ecclesia, resisting Poison/Curse/Stone in Dawn of Sorrow does actually decrease damage.
====Throwing weapons and firearms====
*Throwing weapons ignore the player's stats and always do exactly the amount of damage specified in the item's "Attack" field. The only exception is if the player has Skelerang equipped, in which case it does 1.5x the item's "Attack" field.
*Firearms ignore the player's stats and always do exactly the amount of damage specified in the item's "Attack" field.
===Drop rate===
*If it is Normal Mode:
::Luck has 1× the effect on soul/item drop chances
*If it is Hard Mode:
::Luck has 4× the effect on soul/item drop chances
====Soul drop rate====
The formula will not be executed in Julius Mode or if the rarity of the soul is 0. Note that souls with 100% chance are gathered through event.
*00 is a guaranteed drop, but after that it scales from 01 (rare) to FF (very common, but not guaranteed).
*Rarity = 1 to 8 shows as 3 rarity stars, 9 to 30 shows as 2 rarity stars, and 31 to 255 shows as 1 rarity star
*(Soul Rarity) / (512 - LCK/8)
*If Soul Eater Ring is equipped:
::(Soul Rarity × 2 + 0.125) / (512 - LCK/8)
====Item drop rate====
The formula is calculated if the soul from previous calculation isn't acquired. Julius Mode skip this.
*If Rare Ring isn't equipped:
::The chance of a common drop = (Item1 Rarity × 3) / (1024 - LCK)
::The chance of a rare drop = 256 / (1024 - LCK)
*If Rare Ring is equipped:
::The chance of a common drop = (Item1 Rarity × 3 × 2) / (1024 - LCK)
::The chance of a rare drop = 256 × 2 / (1024 - LCK)
*Once it is been decided that the player is going to get an item drop, it then decides whether they'll get Item1 or Item2.
*If the enemy has only an Item1, Item1 will drop.
*If that Item2 chance fails, Item1 will drop. Or nothing will drop if the enemy has no Item1.
==Castlevania: Portrait of Ruin==
===Drop rate===
====Item drop rate====
Drop × (52 + LCK)/52 × 100/256
==Castlevania: Order of Ecclesia==
Category:Mechanics
Category:Aria of Sorrow
Category:Circle of the Moon