Methods of Evolution

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There are numerous methods of evolution, which define how and when Pokémon evolve. Most Pokémon will evolve by leveling up while others evolve through specific means, such as being traded, achieving maximum happiness, leveling at a certain hours, among others.

Triggers

As of Generation IV, Pokémon may only evolve (having met certain requirements) after one of three events:

• Leveling up
• Being exposed to an evolutionary stone - 24 Pokémon
• Being traded - 16 Pokémon

Of course, it is not sufficient that one of these events happens, but it is also necessary that all the required conditions are met. Therefore, when we are speaking about a method of evolution, we mean both the event and the conditions. Which one of the evolution-triggering events must happen to make certain Pokémon reach its next evolution stage and what conditions must be met is determined for each Pokémon individually.

Pokémon from branched evolution families may evolve into different forms depending on the event that caused evolution and other conditions.

Evolving by level

Most Pokémon are able to evolve by leveling up. This can be triggered by gaining experience in battle, or using a Rare Candy. Some Pokémon required additional conditions before level evolution will take place, such as a specific move being known to the Pokémon. It should be noted that a Pokémon left in Daycare will not evolve—even if all conditions are met—until it's leveled up in battle or given a Rare Candy.

Reaching a certain level

Amongst Pokémon that evolve by level, they will evolve as soon as certain level is reached by gaining enough experience after a battle. If a Pokémon is not able to evolve when it reaches the required level, it will try to evolve every time it levels up again. To avoid this, an Everstone given to the Pokémon will suppress evolution until it is removed.

Example: Ekans evolves into Arbok at level 22.

This method of evolution doesn't have special disadvantages in most cases. However, Meowth, for example, evolves into Persian at level 28, but learns Pay Day at level 32. In Generation IV, Persian cannot learn Pay Day by leveling up, this means that if a player wants to have a Persian with Pay Day, the player must not let Meowth evolve until it learns the move.

Furthermore, Pokémon cannot evolve if they are still in their base form until level 100, because they cannot level up any further.

Happiness

Some Pokémon evolve by leveling up if their hidden Happiness stat is 220 or above. It's more common with baby Pokémon such as Cleffa, but other evolved Pokémon like Chansey (which evolves further into Blissey) require it. This method of evolution was introduced in Generation II.

The following Pokémon evolve in this manner:

• Golbat → Crobat
• Chansey → Blissey
• Pichu → Pikachu
• Cleffa → Clefairy
• Igglybuff → Jigglypuff
• Togepi → Togetic
• Munchlax → Snorlax
• Buneary → Lopunny

Less common conditions

Knowing a certain move

Some Pokémon evolve when they reach a level while they know a particular move, which is available by leveling up. If in any case they are made to forget the moves, the Pokémon must relearn it in order to evolve with the help of move relearner. This method of evolution was introduced in Generation IV.

• Rollout
  • Lickitung → Lickilicky
• AncientPower
  • Tangela → Tangrowth
  • Yanma → Yanmega
  • Piloswine → Mamoswine
• Double Hit
  • Aipom → Ambipom
• Mimic
  • Mime Jr. → Mr. Mime
  • Bonsly → Sudowoodo

Being in a certain area

Since the introduction of Generation IV games, the following Pokémon only evolve by leveling up in the specified area:

• At Mt. Coronet
  • Magneton → Magnezone
  • Nosepass → Probopass
• In Eterna Forest (Moss Rock)
  • Eevee → Leafeon
• On Route 217 (Ice Rock)
  • Eevee → Glaceon

Holding a certain item

Some Pokémon evolve when they level up if they are holding a certain item. In this case, the item disappears after the Pokémon evolves.

• Happiny (holding Oval Stone) → Chansey
• Gligar (holding Razor Fang) → Gliscor
• Sneasel (holding Razor Claw) → Weavile

For more information on how Onix evolves into Steelix, see below.

By time and happiness

The following Pokémon evolve by leveling up if they're happy, but only during a certain part of the day:

• Day
  • Eevee → Espeon
  • Budew → Roselia
  • Riolu → Lucario
• Night
  • Eevee → Umbreon
  • Chingling → Chimecho

Unique conditions

The following Pokémon evolve through a method that is isolated to their evolution line only.

• Mantyke evolves into Mantine when it levels up only if there is a Remoraid in user's party.
• Feebas evolves into Milotic by leveling up if its Beauty stat is 170 or above.
• Combee evolves into a Vespiquen if it is female. Male Combee do not evolve.
• When Nincada evolves into Ninjask (at level 20), if there is an empty slot in the party, a Shedinja will appear. In Generation IV, the player must also have a spare Poké Ball in their bag.

Additional factors

Some Pokémon from branched evolution families evolve into different forms depending on some additional factors. These factors are not conditions for evolution, since they do not determine the possibility of evolution, but what the Pokémon will become after evolution.

• Burmy. This Pokémon evolves at level 20, but its new form is determined by its gender and cloak (and cloak changes according to the place, where it has battled last time).
  • Male Burmy → Mothim
  • Female Burmy → Wormadam, but the type combination of Wormadam is determined by the cloak.
    • With Plant cloak (after battling in the wild) → Bug/Grass Wormadam
    • With Sandy cloak (after battling in a cave or on a beach) → Bug/Ground Wormadam.
    • With Trash cloak (after battling in a building) → Bug/Steel Wormadam.

• Tyrogue. This Pokémon evolves at level 20 depending on its stats.
  • If its Defense is higher than Attack, it evolves into Hitmonchan
  • If its Attack is higher than Defense, it evolves into Hitmonlee.
  • If Attack is equal to Defense, it evolves into Hitmontop.

• Wurmple. It evolves at level 7 into Silcoon or Cascoon, depending on its personality value. This value is hidden, determined when Pokémon is caught and cannot be affected by the player. See the article about personality value for the exact formula.

For Espeon and Umbreon, see above.

Evolving by evolutionary stone

Main article: Evolutionary stone

See also: Pokémon that evolve by evolutionary stone

Some Pokémon evolve when they are exposed to an evolutionary stone. The stone may be applied at any time and causes an instant evolution. The player can decide whether and when to evolve his or her Pokémon, but he or she must choose carefully as most Pokémon will no longer be able to learn certain moves when they evolve in this way, and some (like Raichu and Togekiss) cannot learn any moves by leveling up, although there are exceptions to this rule (see heart scale) and certain moves are exclusive to the stone-evolved Pokémon.

Examples

• Vulpix + Fire Stone → Ninetales
• Poliwhirl + Water Stone → Poliwrath
• Pikachu + Thunder Stone → Raichu
• Weepinbell + Leaf Stone → Victreebel
• Nidorino + Moon Stone → Nidoking
• Gloom + Sun Stone → Bellossom

Usually there are no special requirements for stone-induced evolution, with only two exceptions: Kirlia and Snorunt. They may evolve when they hit a certain level at either gender, or...

Kirlia	male or female	at level 30	→ Gardevoir
	male only	+ Dawn Stone	→ Gallade
Snorunt	male or female	at level 42	→ Glalie
	female only	+ Dawn Stone	→ Froslass

Note that sometimes the Oval Stone is said to be an evolutionary stone, because it is a stone and it is required for an evolution. However, technically Oval Stone is an evolution-inducing held item, which Happiny must be holding to evolve into Chansey when it levels up.

Evolution via trading

Main article: Trade

See also: Pokémon that evolve through trading

A select few Pokémon evolve only when they are traded. The evolution starts immediately after the trade is completed, regardless of the method of trading used. However, sometimes there are additional conditions.

Examples:

• Kadabra → Alakazam
• Machoke → Machamp
• Graveler → Golem
• Haunter → Gengar

A well-known mistranslation in the non-Japanese releases of the Generation I games suggested that after trading a man a Raichu, he said that it had evolved. This fueled speculation as to whether or not there would be a third stage to the Pikachu line in Generation II; a third stage was later realized in the form of a Baby Pokémon, Pichu.

Holding a certain item

Main article: Evolution-inducing held item

See also: Pokémon that evolve by trading with a held item

Some Pokémon evolve when traded only if the are holding a certain item. Like any evolution-inducing held item, the item disappears after the Pokémon evolves.

Examples

The following Pokémon evolve using this method:

• Slowpoke → Slowking: trade while holding King's Rock
• Onix → Steelix: trade while holding Metal Coat
• Electabuzz → Electivire: trade while holding Electirizer
• Magmar → Magmortar: trade while holding Magmarizer
• Porygon → Porygon2 → Porygon-Z: trade while holding Up-Grade, then trade while holding Dubious Disc
• Clamperl → Huntail: trade while holding DeepSeaTooth
• Clamperl → Gorebyss: trade while holding DeepSeaScale

References

• Evolution
• Evolutionary stone
• Evolution-inducing held item