Canonical page: https://rollafisherman.com/mutations/
Content modified: 2026-11-09
Publisher: Roll a Fisherman Field Guide (independent fan guide)

OCTOBER 2026 FIELD GUIDE

# Roll a Fisherman Mutations Guide

Updated Nov 9, 2026

Before using Gold on a fish, check its current income, any rebirth role and the price shown by the Mutation Machine. Mutation results and future income are not guaranteed.

## Are Forest fisherman mutations the same as fish mutations?

The Parts & Hell announcement lists four mutations for Forest fishermen. This guide’s Mutation Machine examples and Gold budget apply to fish. The announcement does not specify how to get the new fisherman mutations or what they cost.

[Read the Parts & Hell update guide](https://rollafisherman.com/wiki/#parts-and-hell)

## How to plan a mutation

Choose a spare fish and note its current Cash/sec. Open the mutation interface with that fish and read the Gold cost and effect shown for the attempt. Reserve the Gold for your next upgrade before setting an attempt budget. Compare the resulting fish with your weakest occupied stand.

## Which fish should you use?

Keep fish required for rebirth and protect your strongest stand earners. Start with a spare that you can remove without interrupting your income. Set a maximum Gold budget and stop when you reach it.

### How many mutation attempts can I afford?

Subtract the Gold you want to keep from your balance, divide the remainder by the displayed cost per attempt, and round down. Your reserve must fit within your balance, and the price must stay above zero and unchanged.

[Use the Gold budget calculator](https://rollafisherman.com/gold/#mutation-budget) to calculate affordable attempts, planned spending and remaining Gold. Enter the price currently shown in-game and update the plan if it changes. The result counts paid attempts, not successful mutations.

[Calculate time to your next rebirth](https://rollafisherman.com/rebirth/#rebirth-calculator) · [Rebirth preparation checklist](https://rollafisherman.com/rebirth/#costs)

## Compare the result by income

Use the fish’s displayed Cash/sec when deciding whether to place it. Compare the same fish before and after an attempt and record the Gold spent. A new variant helps your dock when it improves the stand you will replace.

[Which fish should I keep?](https://rollafisherman.com/fish/#income) · [Gold](https://rollafisherman.com/gold/#spend-gold)

## Mutation FAQ

### Should I mutate before rebirth?

Reserve the fish required for rebirth first. Use a separate spare fish and a Gold budget for mutation attempts.

### What makes a mutation useful?

Its contribution to your occupied stands and your current goal. Compare displayed income and the Gold spent together.

### Should I sell my old stand fish immediately?

Place the replacement first and keep any catch that has a role in your next rebirth.