Pokémon that evolve by level fall into several different categories.
If a pokémon evolves twice and by level the first time, the first evolution requires two experience points to complete UNLESS that pokémon falls into one of the following two groups:
Group 1: Beldum, Bellsprout, Gastly, Geodude, Machop, Oddish, Poliwag, Ralts, Whismur, Zubat
Group 2: Aron, Bagon, Dratini, Duskull, Elekid, Gible, Horsea, Larvitar, Magby, Magnemite, Rhyhorn, Spheal, Swinub, Trapinch,
Members of group one require three experience points to complete their first evolution, and those in group two require four.
If a pokémon evolves twice and evolves by level the second time, it must earn four experience points in its middle stage in order to reach its final evolution UNLESS it is among one of the following:
Gabite, Lairon, Loudred, Metang, Pupitar, Sealeo, Shelgon, Vibrava
These pokémon require five experience points to reach their final evolution.
If a pokémon evolves by level but evolves only once, it requires three experience points to evolve UNLESS it falls into one of the following two groups:
Group 1: Baltoy, Croagunk, Glameow, Grimer, Koffing, Meditite, Shuppet, Slugma, Swablu
Group 2: Anorith, Kabuto, Lileep, Omanyte, Ponyta, Skorupi, Snorunt, Snover, Wailmer
Members of group one require four experience points to evolve, whereas members of group two require five.
Pokémon such as yanma, which require specific moves to evolve, are counted simply as evolving by level, and pokémon such as magneton, which require leveling up in a particular location to evolve, are again burdened with no restrictions beyond those for normal level evolution. The same is true of tyrogue.
Nincada will evolve into ninjask as normal with three experience points. However, if the trainer wishes to claim a shedinja as well as the evolved ninjask, they must pay an additional $30 at the time that their ninjask evolves. Shedinja counts as as first-stage rarity seven pokémon.
There are also some pokémon whose movepools are so restrictive that they are considered nearly impossible to use in battle for the purpose of leveling up. While they may be evolved as normal through the acquisition of battle experience, the trainer may alternatively choose to pay for them to be boarded at a day-care center by the League for the following prices:
$10 - Caterpie, Weedle, Wurmple
$20 - Cascoon, Kakuna, Kricketot, Metapod, Silcoon
$30 - Beldum, Burmy, Combee (f), Magikarp
Pokémon that evolve purely by trading, such as kadabra, may be evolved for free upon being transferred to another player (as a gift or as part of a trade, for example). Alternatively, they may be evolved as though they were in the "high-level-evolution" group of the three-stage families, requiring five experience points to advance from the second stage of evolution.
Finally, pokémon that evolve by happiness can reach their next stage either by participating in six battles or by scoring three KO's. All battles participated in and KO's scored while holding the soothe bell count double. Feebas is considered to evolve by happiness.
