Petz

Petz (Dogz and Catz) is a series of games dating back to 1995, in which the player can adopt, raise, care for and breed their own virtual pets. Petz has sold over 3 million copies worldwide.

Game play
The player starts at the Adoption Center,where they may choose a dog or cat to adopt of a breed and gender of their choosing. Once they have found a pet they like the user can adopt and name the new puppy or kitten. After around three days (real time) the petz become adults. Adult petz can then breed and have kittens or puppies of their own in Petz 3, Petz 4, and Petz 5 (this was not available in the first two lines). Cross-breeding can create different types of petz, called 'Mixed Breeds'.

There are a number of toyz, food/water bowls and treats available. Petz can learn tricks with positive rewards such as petting and treats, or trained not to do something using the punishment (water) spray bottle. Petz must be looked after properly; abused or neglected petz may run away.

Players may share their petz with others who have the game via an E-Mail. Each version allows the importing of petz from all earlier versions. There is also a camera feature, permitting snapshots of petz to be taken and saved as .bmp files.

Other animals include pigz and bunniez. Later versions of the games included a Petz Web Fun Pack, Petz Publisher and a Petz Player web browser plug-in, allowing players to publish their petz online in playable webpages. The Petz Publisher does not work anymore, due to the fact that the website has been remodeled with the newer Petz games by Ubisoft.

Users learned how to reverse-engineer the system, and began producing additional breedz, toys, playscenes, clothes, and developer tools for the games, as permitted by PF Magic, Mindscape, and Ubisoft Entertainment.

Creature design
Body: (ball style design) The petz are modelled as a set of balls joined by lines with variable parameters. The concept for this was developed in an early PF Magic title, the fighting game Ballz for Sega Genesis. This model was scrapped in the 2006 games Dogz and Catz for the PC for a more "realistic" look.

Colors: There are 10 default fur colors that occur naturally in the game. Eye color is not restricted to the 10 default fur colors. In "hexed" breedz/petz the range of colors can be much greater, although all colors must be within the 256-bit selection. Any coat colors other than the default 10 can not be inherited properly and will mutate to inheritable colors in offspring, usually white.

Textures: Textures cover the ballz, imitating fur and stripes.

Paintballz: Some Breedz have splotches of color or texture on their bodies called Paintballz. The spots on the Alley Cat, Calico, and Dalmatian are examples of this.

Breedz
Each Petz breed has its own body shape and color variations.

Petz 2 began with 5 Breedz per game, and new ones were introduced through downloads via the PF Magic website. In addition to what became 10 Breedz, avid Petz fans began using a hex editor to modify the 10 Breedz to form new ones. This hexing continued through Petz 3 as well.

Petz 3 and 4 contain 10 Breedz per game, referred to as the Original PF Magic Breedz. Petz 5 saw the addition of 5 new Breedz per game, referred to as the UbiSoft Breedz.

"Hexies"
Hexed breedz and petz, called "hexies", are petz that have been modified to appear or act a certain way. Color, size, behaviour, sound, shape, texture, paintballz and other variables can be changed this way. This is often used to create new breedz. The term comes from hexadecimal representation, which is modified with a hex editor to create a hexie.

Breeding and Petz genetics
Petz in the game can become attracted to one another and breed to produce offspring. This feature was introduced in Petz 3 and has also appeared in Petz 4 and Petz 5. In Petz 3 and Petz 4, a petz couple could only produce one kitten/puppy per breeding, but in Petz 5 a mother can bear up to four offspring per litter.

The user can encourage petz to fall in love by squirting them with love potions and perfumes and giving them food with aphrodisiac-like qualities, as well as other means. When petz have mated, a heart will appear on the screen informing the user of the female's pregnancy (which generally lasts 3 – 5 days). In that time, females will become noticeably rounder and will require extra food and attention.

Petz's genes carry through to their offspring but can mutate, resulting in different fur and eye colors to that of the parents. The shape and size of body parts is also inherited in "sections;" e.g. the legs, head, and ears could be inherited from one parent and the feet, tail, and body could be inherited from another.

When two different breeds of Petz are bred together, the offspring will have the base personality of one parent (or ancestor). The base personality can be determined by the pet's voice, their personality and behavior and how they pose if they are a cat.

Petz life cycle
When petz have babies, the player is asked to name the offspring. During the first few days of a pet's life, it is blind, small and cannot walk. The mother feeds her infant and the user can do so with the milk bottle.

In Petz 5, when the puppies/kittens are young, they remain in the nursery room with their mother until they are weaned. Only the mother and offspring can access this room and the mother and offspring cannot be taken out separately. When the babies have grown up, the nursery becomes inaccessible. In Petz 3 and 4, the mother and her single puppy/kitten have free access to all areas.

The newborn will later open its eyes and it is able to walk around, jump onto ledges and stop suckling. They can eat from food bowls and drink from the milk bottle, but cannot swallow treats.

Eventually, the offspring will separate from their mothers as they grow up.

Petz since 2006
The 2006 and onwards Petz games bear little resemblance to the original Petz games. Instead of ball-and-line modelled catz and dogz that could grow, breed, and interact with each other, the 2006 Petz features 3D graphics that can be retextured, but not remodelled by players due to the software used to create them (the resulting model files being saved in a format incompatible with other 3D programs).

Six other games were released along with Catz and Dogz. These were Bunnyz, Horsez,Tigerz, Dolphinz, Monkeyz, and Hamsterz. The new Petz games were produced for a range of consoles, including PlayStation 2, Nintendo Wii, Nintendo DS, Game Boy Advance and PC. On the DS and GBA, the player can care for up to three catz or dogz, which are unable to breed, whilst on the Wii and PS2, the player controls a cat or dog on an adventure quest to save the planet from Ivlet, an evil wolf. In this version the player may customize his/her cat or dog to their style, respectively. In the PC version, the player cares for a single pet.

Academic papers

 * Socially Intelligent Virtual Petz
 * Creating Emotional Relationships with Virtual Characters
 * Virtual Babyz: Believable Agents with Narrative Intelligence