Riardi Genetic Codex- Dilution & Double-Dilution

Disclaimer: This page has been created intentionally in such a way that if you have not read the non-genetic dilution & double-dilution page, or anything about colors and patterns yet, the data below should still be understandable.

Dilution and Double-Dilution

Dilution and double-dilution are independent genetic traits that function as a global value-modifier for a riardi's colors. Most colors are groups of four, from darkest shade to lightest tint. Darkest shades are considered a value of '1', while the palest tints are a value of '4'. Dilution and double-dilution act as pigment 'scrubbers' which force the downward shift in a color range's associated numerical value.

Dilution (-1): Applies a single step reduction to the color's value: ex, 4 becomes 3, 3 becomes 2, 2 becomes 1, and 1 drops to white.
Double-Dilution (-2): Applies a double step reduction to the color's value: ex, 4 becomes 2, 3 becomes 1, and values 2 and 1 each become white. Double-dilution is a higher-efficiency pigment scrubber than regular dilution; hence its name.

How Dilution & Double-Dilution Work

Dilution and double-dilution work in the following ways:

The Scope: A riardi's fur pattern dictates how many 'marking slots' the pattern has for proper manifestation: ex, a bicolor pattern has a main fur coloration and one 'marking slot'. Dilution and Double-Dilution both can act upon the singular marking slot, but both cannot display simultaneously in the same slot. A tiger pattern is comprised of the main fur coloration, underbelly, and the stripes- the latter two of which are 'marking slots'.
Modular Expression: Dilution and Double-Dilution can be applied selectively. A riardi can express the dilution or double-dilution gene's corresponding modifier on one, two, or three marking slots, with each slot behaving and calculating individually. They might have dilution on one marking and double-dilution on another.
Ground Exclusion: The main body coloration (the ground) is strictly excluded from this value-shift; it remains at its baseline value regardless of dilution presence. Because of this, any color from the riardi's parentage- be that from the primary, warm, or cool ranges, or even a curious color- from the riard's parentage is displayed, regardless of whether the marking slots are diluted, double-diluted, or immune to dilution effects.
Independence: The trait status of one marking slot does not dictate the trait status of another.

Genetic Transmission and Inheritance

Inheritance Probability: In mixed-heritage lines where only one parent possesses the dilution trait, the offspring has a 50% chance of inheriting the modifier.
Expression Outcomes: Offspring will either display the shift, carry the gene recessively, or not inherit the gene at all.
Masking Factors: The presence of a "pale" phenotype does not confirm the presence of dilution genes; a character can inherit naturally pale base variables from their parentage without any diluting traits being present. Grandparent lineage can also introduce variables that mask the active state of these genes.

Suppression & Immunity Rules

Certain lineages possess a genetic safeguard that completely negates the dilution value-shift.

Dilution Immunity: An innate resistance that prevents the value-shift from applying to a designated marking slot. If present, the markings remain at their unmodified baseline value.
Genetic Cancellation: Dilution immunity and active dilution genes are mutually exclusive. They cancel one another out during fertilization.
Developmental Rule: Because their internal mechanics are fundamentally incompatible, any individual that would have inherited both the immunity trait and an active dilution trait simultaneously cannot be born.

Integration with the Ultra-Bright Mutation

While Dilution and Double-Dilution operate on a per-marking-slot basis, the Ultra-Bright Mutation acts as an external force that overrides these standard rules.

Global Application: the Ultra-Bright mutation applies the color-bleaching effect across the entire riardi, including their main body coloration. This is its signature action, as dilution and double-dilution do not affect the main body coloration.
Cascading Shift: When Ultra-Bright is present, the marking slots and body coloration are dropped by a fixed -2 step value.
Value Wipe: When Ultra-Bright forces a value into a specific "pastel" threshold, the value is automatically neutralized to pure white.
Hierarchy: If Ultra-Bright is present, all standard Dilution or Double-Dilution rules are disregarded in favor of Ultra-Bright's global mutation shift.

Genetic Codes for Dilution & Double-Dilution

Each marking slot on the riardi is assigned a genotype pair. When writing a full riardi genotype, use the vertical bar (|) to separate the slots.

d: Null allele (Non-diluted).
Dl: Regular Dilution allele (-1 shift).
DDl: Double-Dilution allele (-2 shift).
Imm: Immunity allele (Trait suppression).

Genetic Hierarchy & Interaction Rules

When multiple alleles occupy a marking slot, the most efficient "pigment scrubber" always dictates the final phenotype.

Hierarchy: DDl > Dl > d
Dominance Rules:
- Dl/d: Results in -1 Dilution.
- Dl/Dl: Results in -1 Dilution.
- DDl/d or DDl/Dl: Results in -2 Double-Dilution.
- DDl/DDl: Results in -2 Double-Dilution.
Immunity Rule: Imm is dominant over Dl and DDl. If Imm is present in the genotype (e.g., Imm/Dl), the dilution effect is suppressed, and the marking remains at its baseline value.

Note: Imm/DDl is a lethal combination and cannot occur.

**Examples of Dilution & Double-Dilution Notation

Using this system, you can now differentiate between a riardi with a "naturally pale" coat and one that is "genetically diluted."

Phenotype	Genotype (Example Slot)	Interpretation
Natural Base	`[d/d]`	No shift; displays base color value.
Carrier (-1)	`[Dl/d]`	Carries Dilution but shifts by -1.
Expressed (-2)	`[DDl/DDl]`	Double-Dilution expressed (-2 shift).
Immune	`[Imm/Imm]`	Immunity expressed; shift blocked.

Implementing Multi-Slot Patterns

These examples are as follows, with the genetic codes in action:

Bicolor Pattern (1 Main Body + 1 Marking Slot):
- Example: [Dl/d]
- Result: The marking slot is shifted by -1. The body remains at its baseline.
Tiger Pattern (1 Main Body + 2 Marking Slots):
- Example: [Dl/d] | [DDl/d]
- Result: The first marking slot (e.g., underbelly) is shifted by -1. The second marking slot (e.g., stripes) is shifted by -2. The player has a choice to make for creative flexibility.

Applying Modular Shifts to Fur Patterns

When riardi have multiple-slot fur patterns, such as the tiger pattern above, the genotype notation identifies the genetic shift potential for each slot. For example, the tiger pattern has the following:

Genotype: [Dl/d] | [DDl/d]
Available Modifier Pool: One slot holds a -1 potential; one slot holds a -2 potential.

Because the genes act independently on the riardi's marking slots, you get to pick which slot receives which modifier.

Option A (Stripes as -1, Underbelly as -2): The stripes are lightened by a single step, while the underbelly is lightened by two steps.
Option B (Stripes as -2, Underbelly as -1): The stripes are lightened by two steps, while the underbelly is lightened by a single step.

For this example, let's say that the riardi has a main fur coloration of Leaf green- the palest warm green, WG4. Their markings and underbelly are two distinct slots. Since the riardi's parents are both shades of green, you pick Kelp (WG1, the darkest warm green) for both the markings and the underbelly. You now have a riardi whose main fur coloration is very pale Leaf green, with darkest warm-green cheeks, underbelly, and stripes.

Next, let's say this riardi received Genotype: [Dl/d] | [DDl/d]. This means that the underbelly and the stripes both get diluted. Because they are Kelp (WG1), Kelp can be dropped to become Avocado- WG2- from the dilution gene in one of those marking slots, and Lime- WG3- from the double-dilution gene.

You now have a Kelp-green riardi, and they now can have Lime stripes and Avocado-green underbelly, or, you can choose to have the riardi have Avocado-green stripes and a Lime-green underbelly. Depending on which you choose, the results are quite different! Which would you go for in this example?

Summary of Dilution & Double-Dilution Logic

The riardi's fur patterns are maps of potential, rather than rigid assignments, and the player is the final arbiter of which colors go where, providing the expressed dilution genes match the genotype.

The 'ground' rule is that regardless of how complex the riardi's markings may be, the main body remains anchored at whatever its color is. It may already be a pale color, and that's okay, as that means the riardi simply expresses it in its natural, unaffected state from their parentage. The main fur coloration always remains unaffected by dilution and double-dilution, and relies on genetic inheritance for pale colors to occur there.

If a slot has a [d/d] genotype, the player must use the baseline color value for that area, preserving the structural variety across the riardi's fur.