In The Legend of Zelda: A Link Between Worlds, there are four pieces of Master Ore that can be used to enhance the Master Sword. Collecting these will allow you to upgrade your sword twice: the first upgrade requires two pieces and is performed by the Blacksmith in Hyrule, while the second upgrade requires the remaining two pieces and is done by the Blacksmith in Lorule. Upgrading the Master Sword increases its attack power, making your journey through the game more manageable.
Thieves’ Hideout
After rescuing the Thief Girl and escorting her through the dungeon, you’ll encounter a basement room filled with water. In the southwest corner of this room, there are two floor switches. Step on one switch and have the Thief Girl step on the other; this will open a nearby wall. Proceed through the newly revealed passage, follow the hallway, and open the treasure chest at the end to obtain a piece of Master Ore.
Skull Woods
In the final sections of the Skull Woods dungeon, you’ll encounter a room where Link needs to place two eyeballs onto their respective platforms. One of these eyeballs is located on a higher ledge at the southern end of the room. Nearby, there’s a large treasure chest. To reach it, merge into the wall and navigate over to the chest to collect the Master Ore inside.
Dark Palace
On the second floor of the Dark Palace, there’s a room illuminated by six windows. North of this area is a small rectangular room containing a treasure chest. To access this room, ensure that all central platforms are lowered. Place a bomb next to the lower switch, then quickly move to the platform above and strike the other switch to ascend to a higher ledge. Merge into the northern wall and wait for the bomb to detonate, which will cause the wall to rotate, granting you access to the room with the Master Ore.
Philosopher’s Cave (Lorule Graveyard)
Travel to the Sanctuary in Hyrule and use the fissure inside to enter Lorule. Exit to the south and head east to the graveyard. In the northeastern corner, lift the large boulder using the Titan’s Mitt to reveal a hidden staircase. Inside the cave, press the switch on the western side to open a door. Proceed to the northwestern part of the room, climb the steps, and follow the path until you reach a treasure chest. Merge into the eastern wall to reach the chest containing a small key. Use this key to unlock the door in the northwest. In the next room, defeat the three red Eyegores, then pull the right-hand switch to open the path upstairs. Merge into the right wall to access the treasure chest holding the final piece of Master Ore.
By collecting all four pieces of Master Ore, you can fully upgrade your Master Sword, significantly enhancing its power and aiding you in your quest.