Fish

Also known as: donkey, recreational player, fishy

A weak, usually recreational player whose mistakes make them the primary source of profit at the table.

The fish is who the game is built around — without weak players in the pool, the rake and the edge between regs make winning very hard. A fish typically plays too many hands, calls too much, misvalues their holdings, and doesn't think in ranges. Their leaks are large and exploitable, which is exactly why you want to be seated to their left with position on them.

Against a fish, you simplify toward exploit rather than balance: value-bet thinner and bigger because they pay off, bluff less into the ones who never fold, and isolate them preflop to play heads-up pots in position. There's no need to protect a bluff-to-value ratio against someone who isn't checking your frequencies.

Fish come in flavours — the calling station (can't fold), the maniac (can't stop betting), the whale (rich, loose, and high-stakes). Game selection is finding the fish and staying in their game; that decision is worth more bb/100 than most strategic edges.