Green Luck Ring
The Green Luck Ring is a Magical Ring that Link acquires in Oracle of Seasons and Oracle of Ages. The ring can be acquired through a Fortune Link at Vasu's jewelry store.
Treasure Grove from the Subrosian Brothers
Reduce damage from Blade Traps.
"1/2 damage from traps"
In Oracle of Seasons, the ring can be acquired while in Subrosia. Link needs to follow the two Subrosian Strange Brothers for a second time. Continue to follow these Subrosians and then they lead Link to a location in the Treasure Grove where he can dig up a treasure. One of possible treasures is a Seed Ring that becomes the Green Luck Ring when appraised. Link may need to play this Mini-Game several times, as he often gets Gasha Seeds and Ore Chunks as rewards.
In Oracle of Ages, the Ring can be found within a Treasure Chest located in Mayor Plen's House. Mayor Plen's House is located one screen to the west of the Vasu's Jewelry Store. Link needs to use the Long Hook to switch with the pot and gain access to the Treasure Chest that contains the Seed Ring.
When equipped, the Green Luck Ring cuts the damage in half from Blade Traps. This could be particularly useful in specific dungeon locations where there are numerous Blade Traps. However, it is not a ring that Link would want equipped often. Unless Link has the L-2 Ring Box or L-3 Ring Box, it is not recommended that he hangs on to this ring.
Overall, much like the Blue Luck Ring, Gold Luck Ring, and Red Luck Ring, the Green Luck Ring is not very useful and there are better defensive alternatives.