Code:
on fish:
if fish state = caught fish:
if player's offhand tool is {customitems::talisman}:
set {_chance} to a random integer between 1 and 10
if {_chance} is 1:
set {_multi} to 2
send {_multi} to player
on fish:
if fish state = caught fish:
delete item of fishing caught entity
set {_chance} to a random integer between 1 and 1000
if {_chance} is between 1 and 600: #60%
give player {_chance} of {customitems::codas}