The amount of experience an individual Pokémon has is an indication of how much it has battled. In the games, it is quantified as experience points, which a Pokémon can gain in battle by defeating an opponent without fainting first. After a certain amount of experience points have been gained, a Pokémon will grow a level, with each subsequent level requiring more experience to gain, all the way up to level 100, where a Pokémon will no longer gain experience.

A graph of the experience required for Pokémon to level up, color-coded by experience types. Erratic is black, Fast is green, Medium Fast is yellow, Medium Slow is purple, Slow is brown, and Fluctuating is blue.
File:ExpGraphLv50.png
A graph only to level 50 for the experience required for level up. Colors are the same as above.

In the main series

In the main series games, experience is normally gained by all Pokémon who have been sent out against an opponent's Pokémon, divided evenly among them. Experience is gained upon the opponent Pokémon fainting, and its amount is calculated as a function of the fainted Pokémon's level as well as species. Certain items can affect the distribution and amount of experience gained, as can other conditions, such as whether or not the Pokémon was caught by another person or in another language of the game.

Relation to level

 
A graph of the ratio of the experience required to get a Pokémon from Level 1 to a certain level, to that level cubed.

The amount of experience points a Pokémon has is tied directly to its level. Though the amount varies depending on species, always remaining consistent throughout an evolutionary family, a given amount of experience points will always set a Pokémon at the corresponding level. Wild Pokémon of any level will always have the base amount of experience required to reach that level when caught, as will Pokémon hatched from eggs.

All Pokémon fall into one of six experience groups, four of which were introduced in Generation I and two of which were introduced in Generation III. The main difference between these experience groups is the amount of experience points required to reach level 100, and thus, the amount required to reach each level. All those introduced in Generation I are only polynomial functions of the level, while the two introduced in Generation III operate as piecewise functions, changing the equation depending on the level range.

All six functions are cubic functions of the level, but Erratic and Fluctuating are designed to have a constantly changing multiplier of this cube. Erratic has this multiplier go from high (2.0) to low (0.6), while Fluctuation has this multiplier go from low (0.48) to high (1.64).

The cubic nature of these formulas implies that the amount of experience points required to go from one level to the next is a quadratic function.

Though the various experience groups' level-up rates can be calculated using an equation, a lookup table is used in the games after Generation II, to prevent game slowdown and a glitch associated with the Medium Slow formula.

In Generation V the amount of experience gained is dependent on both Pokémon's levels: the lower the victor's level is compared to the defeated Pokémon, the more experience points the victor will gain.

Erratic

File:Expcalc erratic.png
The equation for the Erratic experience group. At levels 50, 68, and 98, both formulas return equal values.

The Erratic experience group, one of the two groups introduced in Generation III, features the lowest level 100 value for experience, at only 600,000 points. Aside from Shieldon, Cranidos, and Finneon's families, all Pokémon in this experience group were introduced in Generation III as well, with most of them being Bug- or Template:Type2s.

Receiving its name due to the highly erratic experience point requirement to reach the next level from level 68 to level 98, Pokémon in this group level up rather slowly in their lower levels, requiring the most experience to grow from level 1 to level 10 (1800 as compared to 1250 for Slow, the next highest requirement), and increase the rate of their growth at higher levels, requiring the least experience to grow from level 90 to level 100 (108654 points as compared to 216800 for Fast, the next lowest requirement).

Due to the erraticness of this function, it actually takes fewer experience points to go from level 99 to 100 than it does to go from level 69 to 70.

For a list of all Pokémon in this group, see Pokémon in the Erratic experience group.


Fast

File:Expcalc fast.png
The equation for the Fast experience group.

The Fast experience group is one of the four experience groups introduced in Generation I, with 800,000 experience points making for a level 100 Pokémon. Many common Template:Type2 Pokémon are in this group, among them the Chansey, Clefairy, and Jigglypuff families.

For a list of all Pokémon in this group, see Pokémon in the Fast experience group.

Medium Fast

File:Expcalc mfast.png
The equation for the Medium Fast experience group.

Among all Pokémon, the most plentiful experience group is the Medium Fast group, which was also introduced in Generation I. Requiring Pokémon to have an even 1,000,000 experience points to be at level 100, it is by far the most average of the experience groups, and the one with the simplest equation: to be at a given level, any Pokémon in this group requires experience equal to that level cubed. This group is also often called "cubic", due to its function being a simple cube of the level.

Interestingly, this experience group actually grows more slowly than the Medium Slow group up until about level 68 (level 47, if considering amount of experience required to reach the next level).

For a list of all Pokémon in this group, see Pokémon in the Medium Fast experience group.

Medium Slow

File:Expcalc mslow.png
The equation for the Medium Slow experience group.

The Medium Slow experience group, like the Medium Fast group, accounts for many Pokémon, containing the second largest amount of them. All normal starter Pokémon are in this group, as are several smaller legendaries, such as Mew and Shaymin. Requiring 1,059,860 experience points for a Pokémon to reach level 100, it is the only one whose level 100 experience is not evenly divisible by 10,000.

The inflection point for this polynomial function is actually at level 4, not level 0. Thus, it actually takes more experience points to go from level 2 to 3 (48) than it does to go from 4 to 5 (39). In Generations I and II, this mislocation of the inflection point causes the experience underflow glitch.

The starter Pokémon are all at level 5 at the start, and are all in the Medium Slow group, so it appears that the Medium Slow group's experience formula was calculated with the starter Pokémon in mind. It is the only function to do so - all the other functions, being simple multiples of the cube of the level, have inflection points at Level 0, meaning that the number of experience points required to advance one level will always increase as the level increases because the level is positive.

For a list of all Pokémon in this group, see Pokémon in the Medium Slow experience group.

Slow

File:Expcalc slow.png
The equation for the Slow experience group.

The final of the four Generation I experience groups, the Slow group features the highest amount of experience required for a Pokémon to reach level 100 in Generations I and II, and the second highest amount since then. Containing many rare, powerful, and legendary Pokémon, Pokémon in this group are typically very hard to raise. At level 100, a Pokémon in this experience group will have 1,250,000 experience points.

For a list of all Pokémon in this group, see Pokémon in the Slow experience group.

Fluctuating

File:Expcalc fluctuating.png
The equation for the Fluctuating experience group. At levels 15 and 36, both formulas return equal values.

The second experience group introduced in Generation III, and a direct opposite to the Erratic group, the Fluctuating experience group contains the Pokémon which grow the slowest of all, reaching level 100 with a whopping 1,640,000 experience points. It is also, unsurprisingly, the smallest of the experience groups, containing only 14 species. Pokémon within this group require the least amount of experience to grow from level 1, needing only 540 points to reach level 10, as compared to 560 for Medium Slow, the next lowest requirement. They also require the most experience points to go from level 90 to 100 - 517340 as compared to 338750 for Slow, the next highest. Like the Erratic function, the Fluctuating group's level-up equation is calculated in a piecewise fashion.

Also like the Erratic experience group, the Fluctuating group gets its name from the wildly fluctuating requirement for each level to go to the next level, from Level 36 to Level 100.

For a list of all Pokémon in this group, see Pokémon in the Fluctuating experience group.

Table

Below is a table. On the left side of the level is the minimum number of experience points required for a Pokémon to be at that level, and the amount of experience points a Pokémon of that level will have when caught from the wild. On the right is the number of experience points required to advance from the respective level to the next level.

Experience gain in battle

Gaining experience in battle depends on the level and species of the Pokémon that was defeated in battle. The higher level a Pokémon is, the more experience points it yields. In Generation V the amount of experience gained is dependent on both Pokémon's levels: the higher the defeated opponent's level is compared to the user, the more experience points the user will gain.

Several other things can affect the gain of experience. If more than one Pokémon is sent into battle, the gained experience calculated by the above calculation will be divided by how many were sent into battle. Note that in Generation V the Pokémon's own level is taken into account after dividing experience, meaning lower level Pokémon will get more experience than higher level Pokémon.

The Lucky Egg and Exp. Share (Exp. All in Generation I) can also further affect the gain of experience. If the Exp. All is in the bag in Generation I, all members of the player's party will gain experience based on how many there are, as if all had been sent into battle. The Exp. Share (since Generation II) and Lucky Egg, however, activate if held, with the Lucky Egg further multiplying experience gained by 1.5×, and the Exp. Share automatically giving half of the experience from a battle to the holder, leaving the rest to be distributed among those that actually participated (this can be exploited to give a Pokémon 3/4 of the battle's experience).

Pokémon that faint do not gain any experience; however, if they are revived before the Pokémon they fought is defeated or switches out, they will still gain experience.

Gain formula

File:ExpGainFormula.png
Formula for experience gain from battle (Generation I to IV)
File:Delta exp gen5.png
Formula for experience gain from battle (Generation V)

Unlike the great variation in formulas among the six experience groups, there is only a single formula used to determine how much experience a Pokémon will gain from battle, to the right. In this formula:

  • a is equal to 1 if the fainted Pokémon is wild, and 1.5 if the fainted Pokémon is owned by a Trainer.
  • t is equal to 1 if the winning Pokémon's OT is its current owner, 1.5 if the Pokémon was gained in a domestic trade, and 1.7 if the Pokémon was gained in an international trade.
  • b is the base experience yield of the fainted Pokémon's species, listed here.
  • e is equal to 1.5 if the winning Pokémon is holding a Lucky Egg, and 1 otherwise.
  • L is the level of the fainted Pokémon.
    • In Generation V, Lp is the level of the victorious Pokémon.
  • s is the number of Pokémon that participated in the battle and have not fainted. If any Pokémon in the party is holding an Exp. Share, s is equal to 2, and for the rest of the Pokémon, s is equal to twice the number of Pokémon that participated instead.

In Generation V, the experience gain formula was revamped. The constant divisor of 7 was changed to 5, and a factor was added that took the battling Pokémon's level into account.

Also, a constant of 1 was added to each battle, presumably to prevent a defeated Pokémon from yielding 0 experience due to a very low ratio between levels.

Example (Generation I to IV)

An originally owned Skitty holding a Lucky Egg and an internationally traded Meowth have just defeated a Level 78 Trainer-owned Garchomp, with an originally owned Salamence in the winner's party holding an Exp. Share.

The base experience yield of a Garchomp is 218, meaning that a Level 78 Garchomp will normally yield 2429 experience points. Because the battle is a Trainer battle, this is multiplied by 1.5 to give 3643.

The Exp. Share will automatically give half the experience points to the Salamence, giving it 1821 experience points. The Skitty gets half of the remaining experience points, with a 1.5 multiplier because of the Lucky Egg. This means that the Skitty earns 1366 experience points.

The Meowth gets half of the remaining experience points, with a 1.7 multiplier because it was internationally traded. This means that the Meowth earns 1548 experience points.

Example (Generation V)

An internationally traded, level 55 Venusaur has just defeated a wild, level 62 Zekrom.

The base experience yield of Zekrom is 306, meaning that a level 62 Zekrom will normally yield 3794 experience points, when defeated by another Pokémon at level 62. However, this Venusaur is at level 55, meaning that it will yield 4260 experience points. The international trade multiplies this by 1.7, giving 7242, and the constant of 1 is added, meaning that this Zekrom will yield a total of 7243 experience points.

Experience underflow glitch

In Generation I and Generation II, level 1 Pokémon in the medium slow group were calculated to have -54 experience points. However, due to the use of unsigned integers, the program took this to be 16,777,162 experience points, and if a Pokémon did not gain enough experience points to wrap this number back down to zero, it would be considered to be at level 100 (having gone over the amount required to be level 100 by over 15 million experience points), and instantaneously jump to this level.

It is due to this bug that no level 1 Pokémon can be found in the wild without abusing a glitch or hacking the game. It is also for this reason that although level 2-4 Pokémon can be found wild, Pokémon hatched from eggs at level 5 when eggs were introduced in Generation II.

This glitch was finally addressed in Generation III, which uses a lookup table, rather than an actual formula, to determine level-up experience (this is also why the two new functions introduced in that generation are able to be piecewise functions). Despite this, Pokémon still hatched at level 5 in that generation. Level 1 Pokémon were not "legitimate" until Generation IV, the first generation in which level 1 Pokémon can be found in the wild and eggs hatch into level 1 Pokémon.

In the Mystery Dungeon series

  This section is incomplete.
Please feel free to edit this section to add missing information and complete it.

The idea behind Experience in the Mystery Dungeon series is the basically the same as in the main series, although the mechanics are slightly different. After defeating a Pokémon, each member of the team will gain the full share of experience points. If at least one move is used while fighting the Pokémon, the experience awarded will be twice the normal value. If at least one linked move is used, the experience will instead triple.

After a certain amount of experience points are gained the Pokémon will level up. This requirement, unlike in the main Pokémon games, is arbitrarily defined, and does not follow any formula.

Unlike in the main games, Pokémon cannot evolve upon level up, although level is a factor in determining whether or not they can evolve.

In the Ranger series

In the Pokémon Ranger games, experience is acquired in an entirely different way from in the main Pokémon games. When a Pokémon is successfully captured using the Styler, the Styler will gain experience points, and a certain number of experience points will cause the Styler to level up. However, each Pokémon of the same species will yield the exact same amount of experience points, as there is no concept of level in the Ranger games.

In Shadows of Almia, certain bonuses can be applied to the experience points gained under certain conditions, such as if the capture was made using only one line, or multiple Pokémon were captured at once.

Trivia

  • The Pokémon with the highest base experience yield is Blissey, with a base yield of 608. The Pokémon with the lowest base experience yield are Snivy, Tepig, and Oshawott, with a base yield of 28.
  • The highest number of experience points it is possible to gain in a single battle is 1,581,409. This can be done by defeating a level 100 Blissey in a Trainer battle, using an internationally traded Pokémon at level 1 that is holding a Lucky Egg. This means that given these conditions, a Pokémon could technically advance from level 1 all the way to level 100 in a single battle (except for Pokémon in the Fluctuating group, which need 1,640,000 experience at level 100, while 1,581,409 experience points would bring them to level 99).
    • Before Generation V, the highest number of experience points it was possible to gain was 13,933. This could be done by defeating a level 100 Arceus, Happiny, Chansey, or Blissey in a Trainer battle, using an internationally traded Pokémon that is holding a Lucky Egg. This means that the most levels that a Pokémon could advance in a single battle is 25, if a level 1 Pokémon in the Medium Slow experience group defeated the level 100 Pokémon as mentioned above.
  • The lowest possible number of experience points for a single Pokémon to obtain in a single battle is one. This can be done by defeating a wild level 1 Minezumi, Choroneko, or any other Pokémon with a base experience yield lower than 100, using a level 100 Pokémon.
    • Before Generation V, this could be done by defeating a wild level 1 Magikarp and splitting the experience points between three battling Pokémon.
  • The Medium Fast experience group is the only group not to have either the highest or the lowest total experience requirement at any level, being bounded by the Slow and Fast functions. Strangely enough, the Medium Slow group is the only one to have both the highest and the lowest total experience requirement in at least one level before level 50.
  • There are no Generation V Pokémon in the Erratic or Fluctuating experience groups. Coincidentally, both groups were introduced in Generation III.