Egg

Generation II

• Generation II introduced the system of Egg creation and hatching that would continue, much unaltered, to the present. The first Pokémon Egg obtainable by the player in the series was a Key Item given by Mr. Pokémon in Pokémon Gold, Silver , and Crystal . The Mystery Egg is to be delivered to Professor Elm in New Bark Town ; he will then study it and have one of his aides return it to the player in the Violet City Pokémon Center .
• Elm's studies show that when a Pokémon Egg is carried with a Trainer with a party of lively Pokémon, it will eventually hatch. This is easily proven, as some time after the Egg is given, if it is kept in the party, it will hatch into a Togepi .
• The player reaching the Daycare on Route 34 marks where the game mechanics of breeding are truly introduced. Though unrevealed in the games (and only ever truly shown by Pokémon Stadium 2 and Pokédex 3D ), Pokémon belong to one or two of fifteen Egg Groups , and those which share an Egg Group and are of opposite gender are capable of breeding. Pokémon without gender can be bred with a Ditto , as can any other Pokémon not in the No Eggs Discovered Group . Pokémon in the No Eggs Discovered Group will not breed with any Pokémon or produce any Eggs.
• Pokémon that hatch from an Egg will come out at level 5, having whatever moves their species can learn by that level, any move both parents know that the hatched Pokémon can learn through level-up, any TM or HM moves they are compatible with that were known by their father, and any Egg Moves their father passed down. The father's moves take priority over the moves the species would usually have at that level.
• These are the only games in which an Egg's status screen differs considerably from that of a normal Pokémon, as all later games use either a modified version of the Pokémon status screen of that game (as is the case in Generation III), or the same status screen, minus some pages (as is the case in Generation IV, V, and VII).

Generation III

• Generation III retained much of the system introduced in Generation II, with only one major change: incenses are introduced that, if held by the appropriate Pokémon, will cause them to produce Eggs that hatch into new baby Pokémon (who were introduced in this generation). There are incenses for Marill 's and Wobbuffet 's evolutionary lines, which allow them to produce Eggs that hatch into Azurill and Wynaut respectively. Presumably, these incenses are meant to keep the results of breeding consistent across generations while still allowing earlier Evolutions to be introduced.
• All other mechanics present in Generation II are present in Generation III, including the system for hatching Eggs, except that Eggs require an extra Egg cycle to hatch. Egg Groups now have more members, but the groups themselves number the same as in Generation II, and no Pokémon have changed groups.
• In Pokémon Emerald , several more mechanics were added. A Pokémon's Nature could be influenced if its mother held an Everstone while in the Day Care, while Pokémon with Magma Armor or Flame Body shorten the hatching process if they are in the party with Eggs.
• In Generation III, a Pokémon Egg's type is listed as ??? .
• No Eggs can be obtained from or traded to Pokémon Colosseum or XD .

Generation IV

• Date
  • • Significance
  Notes: Games
• D P
  • • Pt
  Notes: HG SS

• Generation IV expanded on the mechanics found in Pokémon Emerald , making them standard to the series, as well as added more baby Pokémon only obtainable through incense breeding. In Pokémon HeartGold and SoulSilver , rather than just the female, either parent now has a 50% chance to pass down its nature if it holds an Everstone . In addition to this, Pokémon Eggs now hatch at level 1. This would have been possible in Generation III as well, but was not in Generation II due to a glitch in the programming that caused level 1 " Medium Slow " Pokémon to jump to level 100 instantly when leveled up.
• A minor change in mechanics from Generation III causes Eggs to hatch slightly earlier, with the length of an Egg cycle dropping from 256 to 255 steps. The Manaphy Egg obtainable from Ranger games has its own sprite that is different from other, normal Eggs' sprites.
• Trainers can use the Pokétch Day-Care Checker app to check whether or not an Egg has been produced, unlike in previous generations, where Trainers attempting to breed two Pokémon would need to stay near the Day Care if they wished to get an Egg as soon as it was ready.
• Eggs may also be transferred to My Pokémon Ranch , but they will not hatch as long as they are kept in the game. When the ranch reaches the maximum level (level 25, requiring 999 Pokémon to be present in the ranch), Hayley will offer to trade any Pokémon Egg for her Mew.
• In Pokémon Diamond, Pearl , and Platinum , Eggs cannot be given massages; if attempted, the Massage Girl will exclaim, "That's silly! I'd break that Egg if I tried to massage it!"
• An Egg on the Pokétch An Egg in My Pokémon Ranch An Egg in Pokémon Battle Revolution A Manaphy Egg in Pokémon Battle Revolution An Egg produced by Arceus , about to hatch into Dialga , Palkia or Giratina Manaphy Egg in Pokémon Ranger: Shadows of Almia
• In the Generation IV games, Egg cycles are reduced from 255 steps to 230 steps on certain days. For example, on a reduced-cycle day, a Magikarp will take 1380 steps to hatch instead of 1530 steps.

Generation V

• Building on the mechanics introduced in HeartGold and SoulSilver, Generation V makes it possible for female Pokémon with a Hidden Ability to pass on their Hidden Ability to their offspring, unless the father is a Ditto. The Manaphy Egg is found in the coding of Black and White , but was not used.
• A significant change to the mechanics of Egg cycles in Generation IV causes Eggs to hatch at earlier times; Eggs now hatch when their Egg cycle count drops from 1 to 0, rather than when it is 0 at the end of an Egg cycle, effectively reducing the number of Egg cycles that need to be walked by 1. The length of an Egg cycle was also increased from 255 to 257 steps, but this effect is overshadowed by the change in the hatching trigger.

Generation VI

• Again expanding on mechanics from previous games, Generation VI builds upon the mechanics from Generation V by allowing mothers to pass on Egg Moves and Poké Balls , removing the ability to pass on TMs and HMs from the father, and allowing any Pokémon to pass down Hidden Abilities when bred with Ditto. Another new mechanic is the ability for the parents to pass down five IVs if one of them holds a Destiny Knot .

Generation VII

• Again expanding on mechanics from previous games, Generation VII builds upon the mechanics from Generation VI by allowing fathers to pass on Poké Balls when bred with Ditto and randomizing which Poké Ball is passed down when two Pokémon of the same species breed and they are in different balls.

Generation VIII

• Again expanding on mechanics from previous games, Generation VIII builds upon the mechanics from Generation VII by allowing two Pokémon to pass Egg Moves to each other if one knows the move and the other has an open move slot for it.

Generation IX

• In Pokémon Scarlet and Violet , Eggs can be found during Picnics . Species that produced different baby Pokémon if holding an incense now produce these baby Pokémon naturally. Incenses do not appear in these games.
• In some cases that the game may crash, Shiny Pokémon that are hatched from the Eggs can appear again, but only if the game was saved before the Egg is hatched and it is in the player 's party .