How to Set Trait Conditions (Must-Have & Cannot-Appear Rules)
Nobody wants a laser-eyed skeleton wearing a sunhat next to a beach towel, unless that's genuinely the vibe. Trait conditions are how you stop your generator from making combinations that don't make sense — without manually checking thousands of images yourself.
01 — Why Random Isn't Always Right
A generator's whole job is to shuffle traits into combinations you haven't manually approved. Most of the time that's the entire point — the surprise is what makes generative art fun. But left completely unrestrained, randomness doesn't know that a "Diver Helmet" trait looks ridiculous stacked on top of "Fire Hair," or that your "Robot" body type was never designed to wear a "Bandana."
This is where trait conditions come in — simple rules that tell the generator "these two things are never allowed to appear together" or "if this appears, that must appear too."
Key point: Conditions don't reduce your creativity — they just stop the generator from producing the 0.1% of combinations that would look broken or nonsensical, so you don't have to manually catch them after the fact.
02 — Cannot-Appear Rules: The Bouncer at the Door
A "cannot-appear" rule is exactly what it sounds like — pick two traits (or a trait and a whole layer) that should never end up on the same token. Think of it as a bouncer standing at the door of your generation run, turning away combinations that don't belong together.
Common reasons to use a cannot-appear rule:
- Visual conflicts — a hat that clips through big ears, or hair that would poke through a helmet
- Thematic conflicts — fire-themed traits paired with ice-themed traits, if your lore says those don't mix
- Body-type exclusivity — an accessory designed only for a specific base body shouldn't appear on others
03 — Must-Have Rules: The Package Deal
A "must-have" rule works the other way — if Trait A appears, Trait B is required to appear alongside it. This is less about avoiding visual disasters and more about maintaining internal consistency in your collection's world.
Where must-have rules shine:
- A specific background that only makes sense with a matching character pose
- A rare "glowing eyes" trait that should always be paired with a matching "glowing aura" background effect
- Faction-based traits — if a token has a "Fire Clan" tattoo, it should always carry the "Fire Clan" cape too
Watch out: Stacking too many must-have rules can quietly shrink your usable combination pool more than you'd expect. Always run a feasibility check after adding conditions, not just after setting up your raw layers.
Set Conditions Without Touching a Line of Code
Add must-have and cannot-appear rules across any layers, right from the Conditions tab — free, in your browser.
Try the Generator →04 — Setting Conditions Without Code
You don't need to touch JSON or write a script to enforce any of this. In TheMintLab's generator, the Conditions tab lets you pick any two traits — across any layers — and set either rule with a couple of clicks. The generator then respects those rules automatically during every generation run.
| Rule Type | What It Does | Example |
|---|---|---|
| Cannot-appear | Blocks two traits from ever co-occurring | "Ice Crown" cannot appear with "Fire Aura" |
| Must-have | Forces a second trait whenever the first appears | "Glowing Eyes" must appear with "Glow Background" |
05 — A Sensible Order of Operations
Conditions work best when they're one of the last things you configure, not the first. Get your layers, trait counts, and rarity weights sorted first — then layer conditions on top, and re-run a feasibility check to make sure your combination pool still comfortably covers your target collection size.
Frequently Asked Questions
What's the difference between a cannot-appear rule and a must-have rule?
A cannot-appear rule blocks two traits from ever showing up together. A must-have rule does the opposite — it forces a second trait to appear whenever a specific trait is used, keeping certain combinations locked together.
Do trait conditions reduce my collection's uniqueness?
Not meaningfully if used sparingly. Conditions remove a small slice of impossible or nonsensical combinations — the vast majority of your combination pool stays untouched and random.
Can I set conditions between traits in different layers?
Yes — conditions typically work across any two layers, not just within one. A hat trait can be conditioned against an eyes trait, a background trait, or any other layer in your stack.
Will too many conditions cause generation errors?
It can, if conditions overlap heavily and shrink your usable combination pool below your target collection size. Run a feasibility check after setting conditions to confirm your setup can still hit your numbers.
Rules That Work For You, Not Against You
Trait conditions are the quiet workhorse of a clean generative collection — most collectors will never notice they exist, because the alternative (a broken combination) is the only thing that actually draws attention. Set them thoughtfully, check feasibility, and let the generator handle the rest.
TheMintLab's generator includes full trait condition support — free, no account required.