Daily Brains · strange creatures, a hidden rule. Study the labelled examples, then sort the strays.
Species is the naturalist's logic puzzle in Daily Brains (/daily). Each plate is a page from an imaginary field guide: labelled examples of two or three made-up species ("these are Blorps, those are Zims") and a tray of strays. Work out the hidden rule that separates the species, then sort every stray into its column. Four plates a day climb from Easy to Genius, and every plate is proven fair before anyone sees it.
STORY & LORE
The fairness promise
Every plate shows a rule size: the number of checks the hidden rule makes ("has wings" is one check, "has wings and is round" is two). Before a plate is served, a validator enumerates every rule of that size or smaller in the game's rule language (single checks, their opposites, and AND, OR and either-but-not-both in any nesting; for three species, "A if this, else B if that, else C" in any order) and keeps only the ones that fit the labelled examples. The plate is accepted only if all of them sort every stray exactly the same way, and none of them is smaller than the stated size. So any rule you find that fits the examples and the size gives the right answers, and there is no shortcut rule hiding underneath.
Where plates come from
Daily plates are generated from the puzzle number, so everyone gets the same four plates on the same local day. The generator draws a hidden rule for the tier, breeds a pool of 31 distinct creatures, picks the strays, then adds labelled examples one at a time, always the one that rules out the most rival rules, until only one answer survives. It then removes any example that is not needed, so the plates stay tight. Practice mode serves the four hand-made Field Guide plates first, then unlimited generated plates.
HOW IT PLAYS
Traits
Every creature has eight traits, each drawn so it can be counted on a phone: 1 to 4 eyes, 2 to 4 legs, a round, square or pointy body, gold (light), coral (mid) or plum (dark) colour, plain, spotted or striped skin, a bare head, horns or antennae, wings or none, a tail or none. Rules can name a trait value (has horns, is plum), count (at least 3 eyes, an even number of legs) or compare (more eyes than legs). Hold any creature to read its traits in words.
Sorting and slips
Tap a stray, then tap its species column (or drag it there). Press Check when every stray is placed. A wrong Check is a slip: the game pins one misplaced stray in its true column as a new certain example, and you can try again. Three slips and the plate gets away. When a plate ends, the key is revealed in plain words.
Scoring and the day
Each plate is worth 250 with no slips, 175 with one, 100 with two, 25 if the third slip's pin finishes it, and 0 if it gets away; the day is out of 1000. Speed does not count. The day counts for your streak when at least three of the four plates are sorted, and a perfect day is all four with no slips. The share text lists each tier's result without giving anything away.
THE EIGHT TRAITS
Drawn by the game itself.
GALLERY
THE FOUR PLATES
| Tier | Species | Rule size | What it asks |
|---|---|---|---|
| Easy | 2 or 3 | 1 or 2 | One trait, or a three-way split on one trait |
| Normal | 2 or 3 | 2 | Two traits combined, or a two-step key for three species |
| Hard | 2 | 2 or 3 | Three traits, or a counting idea paired with XOR |
| Genius | 2 | 3 | An either-but-not-both riddle with a counting check, plus a decoy trait that fits almost every example |
FIELD GUIDE PLATES (PRACTICE)
| Plate | Tier | Examples | Strays | Key |
|---|---|---|---|---|
| I | Easy | 8 | 4 | Flits have wings |
| II | Normal | 9 | 5 | Winged ones are Grunches; of the rest, horned ones are Tinks; the others Lurbs |
| III | Hard | 11 | 6 | Snibs are round and (striped or tailed) |
| IV | Genius | 12 | 6 | Zorbits: (even eyes and wings) or horns, but not both. Plum is the decoy. |
REWARDS
| Event | Reward |
|---|---|
| Finish the day with three or more plates sorted | 15 Tickets |
| Perfect day (all four, no slips) | +25 Tickets |
| First Specimen (first finished day) | Bronze · 10 Tickets |
| Clean Plates (perfect day) | Gold · 25 Tickets |
| Taxonomist (Genius plate, no slips) | Silver · 20 Tickets |
| Field Guide (all four Practice Field Guide plates) | Bronze · 10 Tickets |
| Field Season (3-day streak) | Bronze · 15 Tickets |
| Expedition (7-day streak) | Gold · 40 Tickets |
| Natural Historian (30-day streak) | Legendary · 100 Tickets |
VERSION HISTORY
- Prototype: four plates a day (Easy, Normal, Hard, Genius), four hand-made Field Guide plates, and unlimited Practice plates.
- Every plate passes a fairness validator (all rules up to the stated size that fit the examples agree on every stray, and no smaller rule fits); scripts/test-species.mjs re-checks with an independent brute-force checker.