Breeding produces Eggs by putting two compatible Temtem together in the Breeding Center. Eggs may inherit various aspects of the parents such as their stats. Using certain items allows the player to manipulate this process.
Male and female Temtem need to share a type to breed. For example, a female Gazuma (Electric /Wind) can be paired with a male Nessla (Water /Electric), since both Temtem are of different sexes and share the Electric type. Mimit is the only Temtem able to bypass this, being capable of breeding with any other Temtem, no matter the type. Mimit can only pass on SVs and not Egg Techniques.
Fertility determines the number of times a tem can breed. The maximum fertility of tem is 8 that the 7 leaves and 1 stem of fertility tree represent. The full fertility each of which can display a brighter or darker shade of cyan, representing respectively remaining and missing fertility. After production of an egg, the fertility value of the parents reduces by 1. The offspring will inherit the lowest fertility value among both parents after production of the egg. Untamed Temtem have a fertility value depending on the amount of SVs of 49 or 50. For each such value, the fertility is reduced by 0.5, rounded up. Since untamed Luma Temtem are generated with at least 3 maxed SVs, their maximum fertility is 6.
- 1 or 2 SVs of 49 or 50 yields a fertility of 7 (8-1).
- 3 or 4 SVs of 49 or 50 yields a fertility of 6 (8-2).
- 5 or 6 SVs of 49 or 50 yields a fertility of 5 (8-3).
- 7 SVs of 49 or 50 yields a fertility of 4 (8-4).
Breeding is done at the Breeding Center in Superior Omninesia, by talking to the Temtem Breeder NPC. Two Temtem couples can be deposited at a time for 50 each, so long as the player has at least one Temtem in the squad remaining that has not been knocked out. Breeding can be cancelled for each deposited pair without losing fertility or items, as long as an egg has not yet been produced. Once an egg has been produced for each pair, the egg and parental pair have to be retrieved before another breeding session can be started.
Breeding takes 5 minutes if both Temtem are of the same evolutionary line, or 10 minutes if they are not. Hatching eggs in the player's squad takes between 5 and 45 minutes, depending on the species' capture rate. The Incubator device increases the hatching speed by 100% for the firstmost egg in the squad.
Various aspects of the parental Temtem are heritable, some of which depend on the use of items.
Species - The offspring's species will be the same as the first form of the evolutionary line of the female parent. E.g. eggs produced by pairings with female Gazuma will hatch into Ganki. If the parents are a Mimit and a male temtem, the offspring's species will be the first form of the evolutionary line of the male parent.
Fertility - Offspring will inherit the lower value between the parents' fertility values after production of the egg. For example, if one parent had 8 fertility and the other had 6, after producing an egg their fertility will lower to 7 and 5 respectively, and the offspring will be born with 5 fertility as well.
Single values - Each of the offspring's stats have a 40% chance of inheriting the highest SV value between the parents, a 40% chance for the average (rounded up) and a 20% chance for the lower SV value. Breeding gear can be used to force certain stats of a parent to be inherited onto the offspring.
Trait slot - Traits are not inherited without the use of breeding gear. There is a 50% chance for each of both traits the offspring species can have. However, the Engineered DNA Strand will ensure inheritance of the trait slot as viewed in the Tempedia. E.g. a male Nessla with the Hydrologist trait (Nessla's second trait) paired with a female Gazuma will pass on the trait slot to the bred Ganki which gets the Inductor trait (Ganki's second trait).
Techniques - Many species can inherit so-called egg techniques from other species. This is achieved by breeding with parents that have the respective techniques active, i.e. the four techniques that can be used in combat. Other techniques are not inherited and instead are learned by leveling or with use of training courses.
Luma chance - By default the chance of hatching a Luma Temtem is the same as encountering one in the wild, namely 1 in 7,500. For each Luma parent this chance increases x10, leading to odds of 1 in 750 for one Luma parent and 1 in 75 for two Luma parents.
Breeding perfect Temtem
Breeding gear can be used to breed perfect Temtem which have the highest value of 50 for all 7 SVs. For each stat, an associated DNA Strand exists. There are also three DNA Strands associated with two stats each, and one specific to the trait slot. Gender can be influenced using X-Incubator Tickets (Female) and Y-Incubator Tickets (Male). Both will instantly hatch an egg, and increase the chance of getting their corresponding gender from a temtem by 50%. (Multiplicative)
Various ways to create perfect Temtem over multiple iterations of breeding exist, depending on the maxed SVs of parent Temtem, their remaining fertility, the desired traits, and compatible DNA Strands. The general idea is to use gear for maxed SVs that are not shared between the two parental Temtem, to ensure the highest number of maxed SVs on the offspring. An example is displayed on the right.