Personality value: Difference between revisions

A Pokémon's '''personality value''' is an {{wp|Signedness|unsigned}} {{wp|32-bit}} {{wp|Integer (computer science)|integer}} that is created when the Pokémon is first encountered; it is set as soon as the Pokémon appears in the wild, the Pokémon's Egg is first generated/spawned on the {{pkmn|Day Care}} man or another [[Non-player character|NPC]], or the Pokémon itself is received from an NPC. As an unsigned 32-bit integer, its value can be anywhere between 0, which is represented as 00000000 00000000 00000000 00000000 (32 zeroes) in binary, and 4,294,967,295, represented as 11111111 11111111 11111111 11111111 (32 ones) in binary, inclusive. This value was introduced with the [[Pokémon data structure in the GBA|Pokémon data structure]] overhaul that occurred at the start of [[Generation III]], and is generated using the games' [[Pseudorandom number generation in Pokémon|pseudorandom number generator]].

For each operation, the portion of the 32-bit value used will be indicated at the beginning of the section by highlighting, unless the full value is used. The integer's full value will be known as ''p'', other values will be declared as ''p_x'', ''p_y'', and so on. Much of this article will be discussing values in binary.

<code>00000000 00000000 00000000 <span style="background:#FF9999">00000000</span></code>

A Pokémon's [[gender]] is determined by the lowest eight digits (a byte) of ''p'' in binary form; essentially, <code>''p'' [[wp:modulo operation|%]] 256</code>. This value will, from here on out, be known as ''p_gender''.

In a Pokémon species's [[Pokémon base stats data structure in the GBA|base stat structure]], there is a byte called the ''gender threshold'', with a value between <code>00000000</code> and <code>11111111</code>. For genderless Pokémon such as {{p|Magnemite}}, the value of this byte is <code>11111111</code>. For female only Pokémon such as {{p|Nidoran♀}}, the value of this byte is <code>11111110</code>. For male only Pokémon such as {{p|Nidoran♂}}, the value of this byte is <code>00000000</code>. Pokémon with ''both'' genders occupy the rest of the spectrum. For these Pokémon, if the value of ''p_gender'' is <b>equal to or greater than</b> that of the base stat value (the gender threshold), the Pokémon is male, otherwise it is female.

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! colspan="2" | Base stat value

Because gender is determined by a greater than or equal check, Pokémon are not actually evenly distributed between male and female. For example, for a Pokémon with a 1:1 male to female gender ratio, there is actually a 129/256 (50.390625%) chance for the Pokémon to be male and 127/256 (49.609375%) chance for the Pokémon to be female.

If ''p'' is even, that Pokémon has the first [[Ability]] for its species. If it's odd, it has the second. If a species has only one Ability while ''p'' is odd, it gets the only Ability it can. Pokémon transferred from [[Generation III]] to [[Generation IV]] or [[Generation V]] that can get one of the new Abilities will retain the Ability they had in the previous generation; however, if they can evolve and their personality value is odd, they will get the new Ability upon evolution. For example, a {{p|Porygon}} that has the Ability Trace is brought to a Generation IV game. If it then evolves into {{p|Porygon2}}, it may keep Trace (if ''p'' is even), or it may switch to the Ability {{a|Download}} (if ''p'' is odd). The reason this happens is because although the Ability is initially determined by the personality value, the Ability is stored as a separate value in the [[Pokémon data structure in Generation IV|Pokémon data]], and alongside the IVs in Generation III. When the Pokémon evolves in Generation IV, the personality value is rechecked, and a new Ability assigned. However if this Pokémon is transferred to [[Generation VI]], it will keep its original ability slot even on evolution.

Note that a separate bit governs whether a Pokémon has their normal Abilities or Hidden Abilities in [[Generation V]]; the personality value of a Pokémon is always set to have its first Ability in this case, so as to allow the inclusion of a second Hidden Ability in a future generation.

In Generations {{Gen|III}} and {{Gen|IV}} a Pokémon's [[Nature]] is determined by <code>''p'' % 25</code>. From [[Generation V]] onward, the nature is untied from the personality value, and stored separately.

 

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Whether a Pokémon is {{Shiny}} or not depends on the values of the [[Trainer ID number]], [[secret ID number]], and personality value. There is an [[Shiny Pokémon#Generations III and IV|8 in 65536 chance]] (0.012207% or 2⁻¹³) of a Pokémon being Shiny (which simplifies to 1/8192).

Variables ''E'' and ''F'' are declared to hold the values that result.

A bitwise {{wp|exclusive or}} operation (or "xor," written as in ''a'' ⊻ ''b'' = ''c'') means "for each bit of ''a'' and ''b'', that bit of ''c'' is 1 if they are different and 0 if they are the same."' For example, 1100₂ ⊻ 1010₂ = 0110₂. It could also be read as "take ''a'', and flip each bit if the corresponding bit of ''b'' is 1." The operation is commutative, so it doesn't matter what order the variables go in.

 

From [[Generation III|Generations III]] to [[Generation V|V]], if ''S'' < 8, the the Pokémon is shiny. In [[Generation VI]], the Pokémon is shiny if ''S'' < 16.

As an example, let's take a Trainer whose Trainer ID is 24294 and whose Secret ID is 38834.

This Trainer encounters a Pokémon whose personality value is 2814471828.

The ''S'' value is then all of these values XOR'd together.

:''S'' = 0101111011100110₂ ⊻ 1001011110110010₂ ⊻ 1010011111000001₂ ⊻ 0110111010010100₂

:''S'' = 0000000000000001₂

''S'' is less than {{tt|8|16 in Generation VI}} in this case, so this Pokémon is Shiny.

From [[Generation IV]] onward, Pokémon have a [[Characteristic]] which indicates their highest {{IV}}. In the case of a tie, the personality value is used to determine which stat is used.

The stat checked first is the stat with the index of <code>''p'' % 6</code>, then proceeding through the index list of stats (after reaching 5 the game loops back to 0). The first checked stat to be a part of the tie determines the Characteristic that is used.

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{{p|Spinda}} has four spots: two on its face, and one on each of its ears. Each of the four bytes represents the coordinates of the spot on Spinda's face or ears. The first four digits of each byte represents the x-coordinate of the top left of the spot when translated into decimal notation, while the last four represent the y-coordinate of the top left of the spot when translated into decimal. There are [[Spinda (Pokémon)#Trivia|4,294,967,296 different]] spot variations.

In Generation III, {{p|Unown}}'s letter is taken from the modulus of the combination of the least significant 2 bits of each byte in ''p''. With A representing 0, and each letter thereafter representing the following number value (? as 26 and ! as 27), the letter can be determined by:

<code>''u_p'' = ''p_letter'' % 28</code>

In Generation II this is determined using [[individual values]]. In Generations IV and V Unown's letter is determined by a separate byte, unrelated to the personality value.

The value in red will be known as ''p_w''; it is essentially <code>''p'' % 65536</code>.

{{p|Wurmple}}'s evolution does not depend on time of day, despite what many game guides say. In fact, the evolution is determined by taking <code>''p_w'' % 10</code>. If the remainder is less than 5, Wurmple will become a {{p|Silcoon}}, and if it is greater than or equal to 5, it will become a {{p|Cascoon}}.

The day-to-day [[performance]] of a Pokémon, for the purposes of the [[Pokéathlon]], depends on the personality value as well as the day of the month. It also depends on Nature, which is also calculated based on personality value. The five least significant digits govern, from least significant to most significant, Power, Stamina, Skill, Jump, and Speed.

*'''The day of month modifier''': This modifier depends on the day of the month and one particular digit of the personality value (determined based on the attribute in question). It is calculated as (((''Day'' + ''Attribute'' + 3) × (''Day'' - ''Attribute'' + 7) + ''Personality'') mod 10) × 2 - 9, where:

** ''Attribute'' is 0 for Power, 1 for Stamina, 2 for Skill, 3 for Jump, and 4 for Speed

** ''Personality'' is the relevant value of the particular digit

*'''The Nature modifier''': This modifier depends on the Nature of the Pokémon. Each of the neutral Natures raise one attribute by 10 points while lowering another by 10 points, while the other 20 Natures each raise one attribute by 35 points while lowering another by 35 points, based on which [[stats]] they normally raise and lower.

*'''The Aprijuice modifier''': This modifier depends on the [[Aprijuice]] applied to the Pokémon. The Pokémon receives 1.5× the flavor values in the attributes corresponding to the strongest and second-strongest flavors of the Aprijuice, an additional 10-point bonus in the strongest flavor of the Aprijuice, and a penalty to the attribute corresponding to the weakest flavor of the Aprijuice based on its mildness and the sum of the Aprijuice's two strongest flavors (see [[Apriblender]] for further details).

 

Note that the day of month modifier is at most -9 and at most +9 (and only takes on odd values therein). Also as a result, the day of month modifier cycles every 10 days ('''exception''': for Power and Speed, the modifiers in effect for the first day of each month are different from those of Day 11, Day 21, and Day 31, though the latter three have the same modifiers).

 

Also, since Nature is also determined by the last two digits of the personality value, the Nature of a Pokémon will constrain the day of month modifier in Power (and to a lesser extent, Stamina) for a Pokémon. For example, a Hardy {{p|Wurmple}} (last digit 0 or 5) will never get a +9 or a +7 from a day of month modifier in Power; if it evolves into a {{p|Cascoon}} (the last digit is 5) it furthermore entails that its best performance will be on the first day of each month, barring Aprijuice factors (as it has its sole +5 boost on the first day on each month)—in contrast, a Hardy {{p|Silcoon}} will have a +5 boost six times a month (on days ending with 4 or 6).

 

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| Speed

Note that the association of Skill and Jump to Natures is reversed relative to a Pokémon's preferred flavors. That is, a Pokémon which prefers dry food will have a +35 boost in Jump (otherwise associated with bitter foods) rather than Skill. However, giving this Pokémon a dry Aprijuice will boost its Skill, rather than its Jump.

 

The calculated value is then translated into a difference in stars as follows:

{| class="roundy" style="width:auto; text-align:center; background: #C0C0FF; border: 3px solid blue;"

| style="background:#fff" | 4

| style="background:#fff" | < -120

| style="background:#fff" | -119 - -80

| style="background:#fff" | -79 - -40

| style="background:#fff" | -39 - -15

| style="background:#fff" | -14 - 14

| style="background:#fff" | 15 - 39

| style="background:#fff" | 40 - 79

| style="background:#fff" | 80 - 119

| style="background:#fff" | > 120