At its core, Freshwater Fly is a dice drafting and set collecting game, with elements of creative puzzle solving and pushing your luck. Each turn you select one die from the dice pool and assign it an action that relates to the particular fishing maneuver you want to take. Higher valued dice typically earn you more powerful actions, but accumulating lower dice totals can earn you free turns. The dice you select will also unlock or multiply various bonus actions you can use to solve the most stringent fishing puzzles in unique and rewarding ways.

The sets of fish and flies you collect will help you achieve personal and common goals, but to obtain victory you must focus on those goals which overlap in the most valuable ways, while not falling behind in your total fish count. The game ends when a single player catches a seventh fish, achievement points are awarded, and the winner is declared.