A mutation is a special fishing outcome that replaces the normal catch with something else:
Mutations are governed by:
Examples of mutation results players will encounter:
Some mutations explicitly require deep water. If you are too close to shore (not deep water), those entries cannot trigger.
You will notice a strong “late-game” curve:
Exact weights and per-entry probabilities are configured in the mutation tables inside the fishing engine. If you want the wiki to display raw percent tables, add a “Developer Appendix” section and maintain it alongside code changes.