Rarity
Rarity runs:
Common → Rare → Epic → Legendary → Mythic → Ethereal
Ethereal is the secret tier. See below.
How catch chances work
Chances are expressed as odds, roughly 1 in 5 at the common end up to around 1 in 10,000 at the rarest.
Rarity is not global: each zone has its own fish, each with its own chance. But the shape is the same everywhere: every island has something at roughly 1 in 5, it is just a different fish. A Cod at Coconut Cove and a Discus at Bamboo Bay can both be the common one for their island.
So "common" describes how easily you catch it where it lives, not how common it is across the game.
What improves your odds
- Luck on your rod: directly raises your chance of rarer fish
- Bait: not built yet, but planned to give small bonuses
- Zone: rarer fish live further out, and getting there needs a better ship
Ethereal / secret fish
The rarest tier. These fish are never listed: not on this wiki, not in the Fish Dex, not anywhere. They appear as ??? until you catch one yourself.
That is deliberate, and it is the one piece of the game the wiki will not spoil. Fishing them up is the discovery.
Awaiting data
Exact percentages per tier. The fish are being balanced now, and the numbers will land here when they are settled.