How rarity works: from a moth with 50 records to a duck with 32 million
Rarity in Earth Gacha depends on one thing: how many records the species has on GBIF in total. That includes public observations, scientific surveys and museum specimens from all over the world, not only photographed ones. Fewer records, rarer card.
The formula
Every card gets a rarity score:
score = 7.5 − log10(records worldwide) + IUCN bonus
log10 is the base-10 logarithm: every time the record count drops tenfold, the score goes up by 1. We use a logarithm because record counts vary enormously, from a handful to tens of millions, so comparing them directly isn’t meaningful. 7.5 corresponds to about 31.6 million records, the Mallard’s league, so the most common species score close to 0.
The score is then split into five tiers:
| Rarity | Score | Roughly, records worldwide | Example (records when pulled) |
|---|---|---|---|
| UR | 5.8 and up | Under 50 | Titulcia eximia, a moth, 50 records, Malaysia |
| SSR | 5.0 – 5.8 | 50 – 320 | Apistobuthus pterygocercus, a scorpion, 102 records, Saudi Arabia |
| SR | 4.2 – 5.0 | 320 – 2,000 | Panther-spotted Grasshopper, Poecilotettix pantherinus, 422 records, United States |
| R | 3.3 – 4.2 | 2,000 – 16,000 | Smooth-coated Otter, Lutrogale perspicillata, 2,496 records, Singapore |
| N | Below 3.3 | Over 16,000 | False Morel, Gyromitra esculenta, 16,297 records, Finland; Mallard, 32,840,285 records |
For example, Titulcia eximia has 50 records. log10(50) ≈ 1.70, so the score is 7.5 − 1.70 = 5.80, just enough for UR. The False Morel has 16,297 records. log10(16,297) ≈ 4.21, for a score of about 3.29: a hair short of R, so it’s an N.
The IUCN bonus
If a species is listed as threatened on the IUCN Red List, its score gets a bump:
| IUCN category | Bonus |
|---|---|
| Near Threatened (NT) | +0.3 |
| Vulnerable (VU) | +0.6 |
| Endangered (EN) | +1.0 |
| Critically Endangered (CR) | +1.5 |
| Extinct in the Wild (EW), Extinct (EX) | +2.0 |
That way an animal that is photographed a lot but is in real trouble still comes out rarer than an ordinary species with the same number of records. The bonus usually lifts a card about one tier.
Drop rates
Drop rates aren’t probabilities we set; they’re estimates. On November 1, 2026 we drew 627 random photographed observations exactly the way the game does, ran them through the formula above and counted how many landed in each tier:
| Rarity | Estimated drop rate | Collection points |
|---|---|---|
| UR | 0.5% | 100 |
| SSR | 1.8% | 30 |
| SR | 4.6% | 10 |
| R | 18.8% | 3 |
| N | 74.3% | 1 |
Across those 627 records, the median species had about 100,000 records worldwide. Most photos are of common species, which is why three cards in four are N.
Few records doesn’t mean few animals
A GBIF record count reflects how often people have photographed and written something down, and that depends on a lot of things:
- Where it lives: North America and Europe have the most observers, so the same kind of organism gets far more records there than in a tropical rainforest or Central Asia.
- How noticeable it is: birds, butterflies and flowering plants get photographed a lot; small beetles, moths and sea squirts much less.
- How easy it is to identify: only photos identified to species count as a record of that species, so groups that are hard to identify have fewer records.
So a UR card might be a genuinely scarce creature, or just a small insect that nobody has looked for properly yet. Both are worth a look: the first is a reminder of how fragile it is, the second shows how little we still know about the nature around us.
The numbers change
Every pack works out rarity from GBIF’s record count at that moment. As more people upload observations, a species collects more records, so today’s SSR may be an SR in a few years. Cards already in your collection keep the score they had when you pulled them.
Want to give a rarely recorded species one more record? See how to get your own photos into the game.