How growth, speed, luck, and loot actually work under the hood
Every fish has a Growth Multiplier that scales how much size you gain from each food pellet or fish you eat. Higher rarity and higher tier both push this number up dramatically — see the exact per-fish Growth stat for every species and tier on the Fish Dex rather than a duplicate table here. Different food types also carry different base size values, so a Growth Multiplier is a multiplier on top of whatever you're eating, not a flat amount.
Your XP Multiplier controls how fast the loot bar at the bottom of the screen fills up. The amount of food needed to fill the bar and collect a net is inversely proportional to your XP Multiplier — double your multiplier and you need roughly half as much food to fill the same bar. Practically: a bigger multiplier means more nets, faster, for the same amount of eating.
Speed Multiplier also scales by rarity and tier — check the Fish Dex for exact numbers per species. Faster fish survive longer (easier to dodge bigger predators) and catch food more reliably simply by reaching it first. Speed doesn't directly multiply your loot bar fill rate the way XP Multiplier does, but it improves your effective XP over time — a faster fish intercepts more food per minute, which means more XP earned per minute even at the same XP Multiplier.
Swim speed decreases as your size number grows — this is by design, but it's gentle. Even at 1 billion size, your fish still moves at roughly 54% of its starting speed. Your fish's individual Speed stat multiplies on top of this penalty rather than replacing it: a naturally fast fish (like Sailfish, with a Speed stat of 100) largely offsets the size penalty and still feels quick at huge sizes, while a naturally slow fish (like Goldfish, Speed 4.0) feels the penalty far more noticeably.
A quick mechanical summary of what each pass actually does numerically. For pricing and purchase recommendations, see How to Play → Passes.
Boosts are temporary Growth / Speed / Luck / Super Luck / XP / Super XP buffs with fixed durations. For pricing, see How to Play → Boosts. The one mechanic worth understanding here: buying multiples of the same boost stacks their duration, not their bonus amount.
The Fishdex holds all 300 entries (60 species × 5 tiers). Every 10 unique entries you collect grants a permanent milestone reward:
Your total Luck stat is a sum of every source stacked together:
Luck itself caps at 1,000,000%. Here's how the rarity odds shift as Luck climbs from the base value all the way to that cap:
| Luck | Common | Uncommon | Rare | Epic | Legendary | Mythic |
|---|---|---|---|---|---|---|
| 100% (base) | 89% | 8% | 2.4% | 0.6% | — | — |
| 350% | 62% | 14% (cap) | 18% | 6% | — | — |
| 1,000% | 40% | 14% | 28% | 18% | — | — |
| 1,667% | 28% | 14% | 32% | 25.98% | 0.02% | — |
| 2,500% | 15% | 14% | 40% (cap) | 30.9% | 0.1% | — |
| 10,000% | 2% | 14% | 40% | 43.3% | 0.7% | — |
| 30,000% | 0.3% | 14% | 40% | 44% (cap) | 1.7% | — |
| 50,000% | 0.05% | 14% | 40% | 44% | 1.95% | <0.01% |
| 100,000% | 0.01% | 14% | 40% | 44% | 1.94% | 0.05% |
| 250,000% | <0.01% | 14% | 40% | 44% | 1.88% | 0.12% |
| 500,000% | <0.01% | 14% | 40% | 44% | 1.85% | 0.15% |
| 833,333% | ~0% | 14% | 40% | 44% | 1.8% (cap) | 0.18% |
| 1,000,000% (cap) | 0% | 14% | 40% | 44% | 1.8% | 0.2% |
At every Luck value, all six rarity chances always add up to exactly 100% — Luck never changes how often you get a fish, only which rarity that fish turns out to be. Every percentage point gained by Uncommon, Rare, Epic, Legendary, or Mythic as Luck rises comes directly out of the Common pool, which starts at 89% at base Luck and shrinks continuously as Luck climbs (see the table above).
Treasures are the primary way to permanently raise your Luck. Each one, when opened, gives 3 fish rolled with your current Luck stat plus a +100,000% Luck bonus applied just for that roll — so Treasures reliably pull much better fish than a normal net.
Every 50 copies of a fish at its current tier merge into 1 copy at the next tier: Normal → Golden → Rainbow → Glowing → Shadow. Tier is completely separate from rarity — it's pure crafting, unaffected by Luck (see Luck above).
| Target tier | Normal fish required (cumulative) |
|---|---|
| Golden | 50 |
| Rainbow | 2,551 |
| Glowing | 127,551 |
| Shadow | 6,377,551 |
Auto Farm automatically steers your fish toward the nearest visible food. When no food is in range, it may instead path toward the lobby teleporter — and can occasionally get stuck against a wall on the way there.
The In-Tank leaderboard is sorted by your growth/size number, and shows rank, username, your currently-equipped fish (colored by its variety), and current size — visible while you're actually playing.
Separately, the Rarest Fish, Most Kills, and Fish Collected boards are visible from the lobby and painted on the tank wall. All leaderboards only display the top 17 entries without scrolling — on mobile, pull up on the board to reveal more.