When a rod is upgraded, it will increase to a higher level, as represented by stars.

Basic perks will get higher values.
The previously-drawn random perks and values will stay unchanged.
Each time you upgrade a rod, it will receive a new random perk with a random value.

For example: If you want to upgrade a level 2 rod to level 3, you will need an additional four 2nd level rods to do so (excluding the rod you’re upgrading).
Rod perks on the rods used for the upgrade don’t have any influence on the perks of the rod you’re upgrading to.

You can upgrade a rod only with the same level rods and the same fishery.

• Level 1 to level 2 – the rod you want to upgrade + five 1st level rods
• Level 2 to level 3 – the rod you want to upgrade + four 2nd level rods
• Level 3 to level 4 – the rod you want to upgrade + three 3rd level rods
• Level 4 to level 5 – the rod you want to upgrade + two 4th level rods
• Level 5 to level 6 – the rod you want to upgrade + one 5th level rod
• Level 6 to level 7 – the rod you want to upgrade + one 6th level rod