The amount of care given to a Tamagotchi will affect its growth. It can affect it in different ways, and sometimes depends on the character. As a general rule, unhealthier characters are more sensitive to care mistakes, whereas healthier characters can be cared for less well and still avoid getting care mistakes.
Different characters are obtained through different requirements. These requirements are always described on charts showing each growth, requirement and character. These charts are called Growth Charts, and are used for depicting all possible growth outcomes for a given Tamagotchi. Although countless varieties of fan-made growth charts exist, Bandai has released an official one for each release in the vintage era.
Growth charts show all possible characters and the care requirements. For example, a good Tamagotchi Connection Version 4 growth chart would include information on Skill Points required for various characters and which family each character is part of.
Involvements and Guidelines
Hunger and happiness
Hunger and Happiness determine how hungry or happy a Tamagotchi is, normally indicated by four or five hearts. On color Tamagotchi releases, hungry hearts are replaced with rice bowls and the happiness hearts is represented as a gauge unit which becomes longer each time a TamaTomo stamp is earned.
Hunger is filled each time a meal is fed. Happiness are filled in multiple ways, such as feeding a snack or playing a game. Since the 2004 reboot, there are usually two "hidden" hearts on the meter, which means that a Tamagotchi can be fed another two meals after its hungry hearts are all filled (although this typically constitutes as overfeeding). This is the same with happiness, except that snacks can still be fed even after the two hidden happiness hearts are filled. From child stage onwards, feeding a Tamagotchi approximately fifteen snacks in succession will lead to it getting a cavity, however. Prior to the Tamagotchi m!x, adults could not get cavities.
In the FamiTama and Version 5, as adults, missing three consecutive calls for empty hungry hearts will result in an evolution to Puchiputchi. Missing three consecutive calls for empty happiness hearts will result in evolutions of Gozarutchi and Kunoitchi. Overfeeding on three occasions by filling up seven hearts will result in an evolution to Osumotchi. Likewise, In the Royal FamiTama and Version 5 Celebrity, as adults, missing three consecutive calls for empty hungry hearts will result in an evolution to Modeltchi, missing three consecutive calls for empty happiness hearts will result in evolutions to Paparatchi, and overfeeding them on three occasions by filling up seven hearts will result in an evolution to Puddingtchi.
Several releases replace happiness with an identically-functioning mechanic. In the Tamagotchi Angel, the Happiness meter is referred to as the "Effort meter" and can only be raised through playing the game due to candy increasing Angel Power; while the Devilgotch uses friendship, the Hexagontchi uses intelligence and the 4U/4U+ uses love.
On the Plus Color onwards, the size of the happiness meter is based on several factors - from the Plus Colour until the 4U+, it depends on how many of the seven stamps have been collected within that generation, while from the m!x onwards happiness is capped at the halfway mark until adulthood.
Stress is a feature exclusive to Tamagotchi Music Star. If a Tamagotchi's stress level is kept low, it will become happier and will evolve into a character of better care. The highest stress level is 99. After a Tamagotchi's stress level exceeds a certain threshold (for instance 70) it will eventually skip concerts, refuse to practice and so on, further boosting its stress level. Eating food besides Baby Food and Baby's Milk, playing games besides the ones accessible from the "Away" menu, and playing with its favorite toy, as well as praising it, will lower a Tamagotchi's stress level. However, practicing, being given a time out or a toy it doesn't like, the games accessible from the "Away" menu and becoming sick will all increase stress.
In the vintage era, a Tamagotchi might call out for no reason. When this happened, users had to select the discipline icon, therefore adding to the training meter. In the Tamagotchi Angel, the equivalent to discipline is praise, used whenever the angel praying. Praising a praying angel will increase their good deeds meter. If praising whenever it was not the case, one happiness/effort heart will be deduced. A similar concept was introduced with the Genjintch Tamagotchi except making pottery and praising would increase the evolution meter, which would contribute to evolution. In the TamaOtch, both a training and a discipline meter exist. The training meter is different from discipline, and in this version alone, refers to how much training (the forth icon from left on the first row) has been completed.
The training feature is the same, but is now split into "Time Out/Punish" (しかる scold) and "Praise" (なでる praise).
Weight is a factor appearing in most releases. Weight increases when a Tamagotchi is fed and decreases when games are played, and the lower a Tamagotchi's weight the healthier it is. This feature was replaced with Tenshi Power/Angel Power on the Tamagotchi Angel and is similar to the Devilgotchi's Devil Power feature. On certain versions such as the aforementioned two and the Morino, the higher the weight or the equivalent factor the better the evolution will be. This is a double-edged sword on the Devilgotch - while a higher DP results in a better evolution, it also means the Tamagotchi will be naughty more often and plays a higher risk of allowing the DP to cross the 90 point threshold that triggers a Bad End.
A Care Mistake, also known as a 'care miss', a 'miss care', or simply a 'miss', is a variable that appears on all Tamagotchi releases. It is a measure of how many times the user has forgotten to care of their Tamagotchi, which factors into what character it will evolve into or how close it is to Death. While it is not possible by normal means to measure the total number of Care Mistakes at any given time, some releases, such as the Tamagotchi Connection Version 2, have an internal care mistake counter which can be made visible through rubbing pencil graphite over the jumper marked J8 on the back of the circuit board, similar to when debugging the unit. 
When one or more meters are empty, the "Attention" icon appears, and a beep is heard. In the modern Tamagotchi releases such as the Tamagotchi Plus Color, a speech bubble which contains either the user's name (or what the user entered for their name) or a phrase such as "I'm hungry", or a flashing exclamation mark above the character's head while it shows a surprised expression. If fifteen minutes have elapsed and the user has not tended to the Tamagotchi's needs, the attention icon will turn off and the additional graphic will disappear, resulting in a care mistake. If both meters empty and are not tended to before the attention icon turns off, this counts for two care mistakes. Not turning the lights off after a Tamagotchi has gone to bed will result in a care mistake as well (though the grace period is much longer on certain releases, even going up to an hour), except on releases (such as the color Tamagotchis) where the light icon is absent.
Physical/mental care and tiers
A physical care mistake happens when the user does the following:
- Let the hungry meter stay empty until the attention icon turns off.
- Fail to respond to a discipline call (scolding).
- Don't cure it when it is sick.
A mental care mistake happens when the user does the following:
- Let the happiness meter stay empty until the attention icon turns off.
- Fail to respond to a discipline call (praising).
- Leaving the light on when it sleeps.
Doing well in games can make either type of care improve by reverting one care mistake. For example, if an Ichigotchi on the V1 has received three physical care mistakes but no mental mistakes, they should evolve into Hanatchi. However, winning Jump enough times might result in an evolution to Kuchipatchi or Mametchi instead.
On the V5 and V5.5, only the calls related to empty hunger or happiness will count towards an adult evolving into Puchiputchi and Gozarutchi/Kunoitchi on the V5 or Modeltchi and Paparatchi on the V5.5.
On the V1, V2 and V3, adults are grouped into five tiers.
- The Serious adults are the healthiest, obtained with 0-1 care mistakes in both care categories, while Normal adults are obtained with up to 2 care mistakes.
- Having at least 2 or 3 care mistakes in one of the categories will result in a Naughty or Frail adult depending on whether the care mistakes were related to mental or physical care. Good physical care and subpar emotional care obtains a Naughty adult, while the reverse obtains a Frail adult.
- Stubborn adults are the unhealthiest, obtained with at least 2 or 3 care mistakes in both physical and emotional care.
Failure to respond to a call within fifteen minutes may result in it becoming sick. This can also happen if more than one poop is left on the screen for a certain amount of time, or if it is untreated when sick. On some releases, missing calls for discipline will not result in Care Mistakes. A certain number of Care Mistakes are required to obtain a specific character on most releases; for example, on the Tamagotchi iD L 15th Anniversary Version, Young Oyajitchi can evolve into Oyajitchi with at least 6 care mistakes.
The more care mistakes occur, the closer a Tamagotchi is to either death or running away from home. The number of care mistakes in a certain growth stage required to trigger the scenario vary from release to release. In the Entama series, obtaining five care mistakes in a single growth stage will trigger the death sequence. Also, the time that the player has to respond to the call shortens with the number of care mistakes the Tamagotchi has. Some modern Tamagotchi releases, such as the Keitai Kaitsuu Tamagotchi Plus, Chou Jinsei Enjoi Tamagotchi Plus and the Tamagotchi Plus Color, have ways of preventing death; should death be avoided, one Care Mistake will be reversed. Care Mistakes can also be reversed through the use of a special medicine obtainable on some versions, although it has no effect on evolutions. Less than 6/7 units filled on the discipline bar on the Tamagotchi Ocean at the end of a growth stage will also result in death, as will getting sick or injured four times in a single growth stage.
Friendship is a feature exclusive to the TamaTown Tama-Go. The more hearts filled, the better impact it will have on the Tamagotchi's growth.
Care-based evolution has been retained across all Tamagotchi releases from 1996 to date. The vintage era created a system involving a certain teen having a certain set of possible adulthood evolutions. In the original Tamagotchi, the better care teen would be able to evolve into all six possible adults, whilst the worse care teen could only become three of them.
In Tamagotchi Connection Version 2 and Version 3, the care given to a parent determines the child evolution which will occur from the resulting baby. If the parent was given good enough care when a teen, the baby could develop into Kuribotchi/Kinakomotchi and Kuchitamatchi/Mohitamatchi on the V2 and V3, respectively.
Care does not affect the growth in the Tamagotchi Connection Version 5 and Tamagotchi Connection Version 5 Celebrity. Instead, there is a new feature called Bonding, which steers the evolution in these versions. That said, however, there are three neglect-exclusive families obtainable at adult stage.
A similar system to that of the original Tamagotchi exists for some of the modern pets, although now genders and sometimes generations have an effect on growth.
The Tamagotchi 4U's Personality Stage form involved a certain adult character evolving into characters revolving around that character. The method of obtaining these characters depends on the original character.
|General Functions||Care • Health meter • Meal • Snack • Training • Poo • C-click reaction(Close Up) • Shop • Notebook|
|Growth||Egg stage(Cocoon) • Baby stage • Child stage(Young Forms) • Adult stage(Personality stage) • Post-adult stage • Sickness • Death(UFO) • Tamagotchi Life Cycle • Generation(First Generation) • Evolution|
|Other Features||Bonding • Tamacom • Bump • Marriage • Gotchi Points • Skill Points • Jewelry • M!xing • Tamagotchi Power • TamaTomo • Color Changing Foods • Color Genetics and Combinations|
|Species||Gaiatchi • Humans • Predator • Tama Pet • Tamagotchi Subspecies|
|Tamagotchi Device||Batteries in a Tamagotchi • Debug (Tamagotchi Programming) • ROM Testing|