Allele – The different forms of a gene. Y and y are different alleles of the gene that determines seed color. Alleles occupy the same locus, or position, on chromosomes. In rabbits, many color genes have only two known alleles, but some have as many as 5. Those genes with only two alleles usually have one that is dominant and one that is fully recessive. For example, (B) is the dominant black allele and (b) is the recessive chocolate (brown) allele. Those that have more than two often have some alleles that are not fully dominant or recessive. The C-Series includes 5 known alleles, only 4 of which are included in the game. The C-Series includes: Full Color (C), Chinchilla (cchd), shaded (cchl), Californian (ch), and Albino (c). These are listed in order of dominance. The shaded allele is not fully dominant over the ones below it, and has been left out of the game.

Carrier – An individual that is heterozygous for a single recessive gene. In other words one that has a recessive gene but does not show it.

Dominant Trait – A trait expressed preferentially over another trait.

Eumelanin – One of the three basic types of melanin. It is responsible for the brown and black colors in fur, hair, and skin.

Epistasis – One gene masks the expression of a different gene for a different trait.

Genotype – The genetic constitution of an organism with respect to a trait. For a single trait on an autosome, an individual can be homozygous for the dominant trait, heterozygous, or homozygous for the recessive trait. Yellow seeds are dominant, but yellow seeded plants could have a genotype of either YY or Yy.

Heterozygous – Differing alleles for a trait in an individual, such as Yy.

Homozygous – Both alleles for a trait are the same in an individual. They can be homozygous dominant (YY), or homozygous recessive (yy).

Hybrid – Heterozygous; usually referring to the offspring of two true-breeding (homozygous) individuals differing in the traits of interest.

Law of independent assortment (the “Second Law”) – Mendelian principal stating that genes for different traits are inherited independently of each other. In other words the choice of which allele of each series gets passed on to the offspring is not affected by any of the other alleles.

Law of Segregation of Genes (The “First Law”)  – Mendelian principal explaining that because each organism has two different alleles, it can produce two different types of gametes. During fertilization, male and female gametes randomly pair to produce four possible combinations of alleles. In other words only ONE allele of a pair gets passed on from parent to offspring.

Law of Dominance (the “Third Law”) – This law says that some alleles are dominant and others are recessive. The phenotype (what we see) is determined by the (one) dominant allele, even though the other allele may be recessive or dominant. In other words, if there is a dominant allele, we will only see the effects of that and not the effects of the other allele.

Melanin – (Wikipedia Entry) The natural pigment found in living things. In most furred animals, it consists of two main compounds: 1. Eumelanin, which is responsible for black/brown, and pheomelanin, which is responsible for the red/rufous colors,

Pheomelanin – A type of melanin found in red hair; it contains sulfur and is alkali soluble; elevated levels are found in the rufous type of oculocutaneous albinism. [G. phaios, dusky, + melas (melan-), black]

Phenotype – The physical appearance of an organism with respect to a trait, i.e. yellow (Y) or green (y) seeds in garden peas. In rabbit color genetics, the dominant trait is normally represented with a capital letter, and the recessive trait with the same lower case letter.

Recessive Trait – Trait of an organism that can be masked by the dominant form of a trait.

Trait – Characteristic that is inherited; can be either dominant or recessive.

True-Breeding – Homozygous for the true-breeding trait.

Wild-type Allele – The non-mutant form of a gene, encoding the normal genetic function. Generally, but not always a dominant allele.

Game Terms

Consistent Mating – Sometimes a kit will provide information about the unknowns in the parents. A consistent mating is one where the unknowns determined by all kits in the litter are consistent.

Gene Pool – (aka Stock, or draw pile) The remainder of the deck of cards after the original hands are dealt. It is usually placed face down, and from whence cards may be drawn.

Go Out – Get rid of the last card in the herd.

Herd – (aka Hand) The cards dealt to a player; the cards they hold at any stage in the game.

Legal Mating – When a card chosen as the offspring of 2 parents is one that is possible according to Mendel’s Laws.

Litter – A group consisting of 2 parents and up to 4 offspring.

Mating – (aka Meld, Set, Run) Three or more cards that form a legal mating.

Retire – After picking a new card, you reduce the herd by placing one card on the top of Retirement (discard pile) face up thus ending one’s turn.

Retirement – The pile of cards, next to the gene pool (stock), into which each player in turn places their discard.

Singleton – A group consisting of 2 parents and one offspring.


Buck – A male rabbit.

Colony– In domestic rabbits a colony is a way of housing a number of rabbits where they all live loose in a large space together. It has some advantages as well as some disadvantages over keeping rabbits in  individual cages.

Dewlap – A flap of loose skin often seen under the necks of does (females), especially the large breeds.

Doe – A female rabbit.

Guard Hairs – These are the coarser (stiffer) hairs in a rabbit’s coat that give it resilience and protect the rabbit from the elements.

Herd – The commonly used collective noun for a group of domestic rabbits. Other collective nouns used for rabbits are:  Warren, Bury, Trace, and Trip.

Intermediate ring – Rabbits can have several different colors along the shaft of a single hair. The middle part is called the intermediate ring. The rabbit in the image (right) has a brown intermediate ring.

Kindle – What it’s called when a rabbit gives birth.

Kit – A baby rabbit.

Rex– The breed of rabbit used in the photos on the cards. These are medium large rabbits (7.5 – 10.5 lb.) that have a very distinctive coat. The undercoat and the guard-hairs are the same length, and the entire coat stands on end, giving the rabbit a very plush feel. The short guard hairs also intensify the color.

Ruff – A roll of fur sometimes seen around the lower hindquarters of larger rabbits.

Undercolor – Rabbits can have several different colors along the shaft of a single hair. The part closest to the skin is called the undercolor.  The rabbit in the image (right) has slate grey undercolor.

Undercoat – These are the softer hairs that help to insulate the rabbit, keeping both the cold and the heat out.

Rabbit Color Terms

Agouti – The color pattern that includes banded hairs. It includes the following colors: Castor, Amber, Opal, Lynx, Chinchilla, Squirrel.

Amber – Surface color is to be light reddish-brown, carried well down the sides, lightly, and evenly tipped with chocolate. Intermediate ring color is to be golden orange, clearly defined over dove-gray undercolor. Belly is to be white or tan over dove-gray undercolor. Ruby cast over eyes permissible.

Broken – When a rabbit’s color appears as spots or patches over white, the color is called broken.

Californian – This is a temperature-sensitive color that is all white except for the extremities – the ears, feet, tail, nose, and sometimes the ruff or dewlap.

Castor – The original wild color as it is seen in a Rex rabbit. In a Rex, the color is to be rich, dark chestnut or mahogany brown, as even as possible over body, head, and legs. Intermediate ring color to be a rich orange or rufus red, clearly defined over slate blue undercolor. Fur to be lightly and evenly tipped with black. Belly color to be white or tan over slate blue undercolor.

Chinchilla – Rex color that resembles real chinchilla. The undercolor is to be a dark slate at the base. Intermediate portion of pearl is to be as light as possible (base to be definitely wider than intermediate portion), with top edge being a very narrow black band, above this is a very light band brightly ticked with black hairs. Either wavy or even ticking permissible to make the beautiful chinchilla surface color. Neck fur is lighter in color than the body, but strictly confined to the nape of the neck. The chest is to be lightly ticked with a uniform shade of pearl, slightly lighter than the body. The body color is to extend as far down the sides as possible. The belly surface color is to be white. Eye circles are to be well defined, narrow, and light pearl in color. Blue gray eyes permissible.

Lynx – Rex color. Intermediate or ring color is to be as bright fawn as possible, clearly defined over white to off white undercolor. Fur is to be lightly and evenly tipped with lilac, not hiding the fawn, but giving a lustrous, lilac appearance. Belly is to be white/off white with an off white undercolor.

Opal – Rex color where the top color is a rich, medium blue, carried well down the sides. Intermediate, or ring color, is to be golden tan, clearly defined over slate blue undercolor. Belly is to be white or tan, over blue undercolor.


Otter – The tan color as seen in the Rex rabbit.

Sable – Rex color where the saddle is an even, rich sepia brown, shading gradually to rich chestnut on the flanks. Head, ears, legs, and upper side of tail are to match the saddle. Chest color is to match the flanks. Color is to go well down the fur shaft, with undercolor to match shadings throughout. Ruby cast over eyes permissible.

Saddle – The area of a rabbit’s coat where a saddle would sit, if there were such a thing as a rabbit saddle.

Seal – Rex color where the saddle is a rich, dark sepia, shading only to slightly paler on flanks, chest, and belly. Color is to go well down the fur shaft, with undercoat to match shadings throughout. Saddle color is to extend from nape of neck to the tail.

Tan – A rabbit color where most of the upper body is a solid color. The area around the eyes, inside the ears, and the underneath part of the body a light cream or white, and there is a distinctive tan colored border between the light and dark parts.