MYO Guide & Trait Rules
Make Your Own Arcanus — how the star system works, the 4-star MYO budget, and how traits stack.
Start here
Read the Species Guide and browse the Trait Encyclopedia before you start. Every Arcanus shares the baseline anatomy below unless a trait says otherwise.
Want to skip the math? Open the MYO Builder — pick your traits and it tallies stars automatically.
The star system
Every trait has a rarity. Rarity is shown as a colored label and a star cost. Very Common traits use a white star (☆) and are always free — they never count toward your MYO budget. Everything else uses black stars (★) equal to its rarity.
| Rarity | Stars | Cost | Notes |
|---|---|---|---|
| Very Common | ☆ | 0 (always free) | Default-looking traits. Free even outside the budget. |
| Common | ★ | 1 black star | Counts toward your star budget. |
| Uncommon | ★★ | 2 black stars | Counts toward your star budget. |
| Rare | ★★★ | 3 black stars | Counts toward your star budget. |
| Very Rare | ★★★★ | 4 black stars | Uses an entire standard MYO on its own. |
The 4-star MYO budget
A standard MYO may spend up to 4 black stars total across all of its traits. Very Common (☆) traits are free and do not count. Traits are stackable — you can combine a Pupil, Iris and Sclera on the same eye, for example, but each one pays its own star cost.
★ + ★ + ★ + ★
Four Common traits.
★★ + ★★
Two Uncommon traits.
★★★ + ★
One Rare + one Common.
★★★★
One Very Rare trait — uses the whole budget.
★★★★ + ☆☆…
Add as many Very Common (☆) traits as you like for free.
★★★ + ★★ = ★★★★★
Stacking Goat Pupil (Rare) + Heterochromia (Uncommon) — over budget, needs an extra upgrade.
Going over budget
Extra stars can be bought as paid upgrades or earned through gameplay (events, prompts, shop currency). See the upgrade pricing further down this page.
Example builds
Four Common traits
★★★★ · 4/4
| Horn Shape | Cow | Common★ |
| Horn Texture | Smooth | Very Common☆ |
| Tail Type | Curled | Common★ |
| Ears | Standard | Common★ |
| Nose | Standard | Common★ |
Two Uncommon traits
★★★★ · 4/4
| Horn Shape | Pronghorn | Uncommon★★ |
| Iris | Heterochromia | Uncommon★★ |
| Horn Texture | Smooth | Very Common☆ |
One Rare + one Common
★★★★ · 4/4
| Horn Shape | Fallow Deer | Rare★★★ |
| Tail Type | Curled | Common★ |
One Very Rare trait
★★★★ · 4/4
| Horn Mutation | Wisp | Very Rare★★★★ |
| Horn Shape | Pointed | Very Common☆ |
Over budget — Goat Pupil + Heterochromia
★★★★★ · 5/4 · over
| Pupil | Goat | Rare★★★ |
| Iris | Heterochromia | Uncommon★★ |
Stackable: each piece pays its own star cost. Total ★★★★★ exceeds the 4-star MYO and needs an extra upgrade.
Anatomy you cannot skip
Horns
All Arcanus have horns. They can break, but only antler-type horns shed and re-grow. Default is one pair (or a single horn if the trait is single-horn). Extra pairs are an upgrade.
Ears
Ears have some mobility but cannot stand fully upright or fold flat against the side of the head.
Scales
All Arcanus have scales unless they take the Scaleless trait. Placement and rarity determine the star cost.
Hind legs
All Arcanus have reptile-like hind legs with no paw pads. Raptor claws vary in size but are always present.
Front feet
Front feet are canine-like — pads, four toes, blunt claws.
Setting
City Arcanus live in medieval-like times. Outside the cities, tribes, villages and nomadic groups reside. Ref designs stay neutral or on-theme — no time-displaced clothing or accessories.
Category guides
Each trait category has its own rules — horns are modular, eyes stack, scales and spikes are priced by placement. Read the relevant guide before you build.
Trait Reference
Browse the full Trait Encyclopedia →
Every documented horn, eye, tail, tooth, tongue, ear, nose, scale, and spike — colour-coded by rarity. Use this when building your MYO trait list.
Buying upgrades
After your free MYO, you can purchase upgrades to add stars beyond the 4-star budget, raise rank, or add elements. The rank ladder must be climbed in order.