A big swordfish is an abnormally large swordfish caught while fishing for swordfish at any cage/harpoon fishing spot, requiring 50 Fishing to catch (or 70 Fishing and 50 Strength for barehanded fishing). Players have a 1/2,500 chance to receive a big swordfish in place of a raw swordfish;[1] catching one results in the game message You catch an enormous swordfish! instead of the usual You catch a swordfish. If fishing with a fish barrel, a big swordfish will be placed into the inventory.[2] Additionally, big swordfish cannot be cooked.
The benefits of Rada's blessing and spirit flakes will cause two big swordfish to be caught at once if either item activates.[3] The extra big swordfish will not be counted in the collection log if this happens.
The drop rate is 1/2,500 every time a raw swordfish is caught. The drop rate of raw swordfish itself varies with Fishing level and harpoon used, so a single figure cannot be quoted.
^Jagex. Mod Ash's Twitter account. 13 April 2015. Archived from the original on 26 March 2019. Mod Ash: "Bass = 1/1000. Swordfish = 1/2500. Shark = 1/5000."
^Jagex. Mod Ash's Twitter account. 8 June 2022. Archived from the original on 9 July 2022. Mod Ash: "You can still receive the big fish, and it'd have to go to your inventory."
^Jagex. Mod Ash's Twitter account. 2 March 2023. Archived from the original on 2 March 2023. Mod Ash: "[Does the fishing boost from both Rada's Blessing 4 and Spirit Flakes apply towards the chance to get a Big Fish (Shark/Swordfish/Tuna) while fishing?] I believe they can double the big fish these days. Originally they wouldn't, but there was a rewrite since then that applied the bonus more widely."
^Jagex. Mod Ash's Twitter account. 21 August 2023. Archived from the original on 29 August 2023. Mod Ash: "Yeah, the answer to that question changed since March 2020 - I think we did a rewrite of the core fishing code during the installation of a League." The earliest occurence of a player reporting a catch of two big fish took place on 23 September 2021.[4] The rewrite in question likely dates from the implemention of Trailblazer League.