Mirror Shield

The Mirror Shield is a powerful shield that generally allows Link to reflect light and other forms of energy from one place to another.

A Link to the Past
The Mirror Shield is the third level shield found in A Link to the Past's Turtle Rock dungeon. It is better than the previous two shields, known for its ability to stop beams, but you can only see half of Link's body behind this giant shield.

Link's Awakening
In Link's Awakening, the Mirror Shield was found in Eagle's Tower and is essential for getting to the last dungeon, Turtle Rock.

Ocarina of Time
In Ocarina of Time, the Mirror Shield was the final shield that Link acquires in his adventure. Found in the Spirit Temple on a ledge that can only be reached by going through the temple. Unlike the Hylian Shield, the Mirror Shield has a polished surface, allowing it to reflect light. This allows the player to solve the light puzzles in the dungeon. Otherwise, the Mirror Shield acted the same except for the fact it destroyed the rocks Octoroks spat, instead of reflecting them.

The Mirror Shield also plays a part in defeating Twinrova, the boss of the Spirit Temple. When Koume and Kotake are separate, the Mirror Shield can be used to reflect - and in turn, direct to the other sister - the fire or ice beam that a sister will fire at you. When in their combined form, the Mirror Shield can absorb Twinrova's energy, and after three of the same type of energy is absorbed, a beam of that element is fired which can stun Twinrova temporarily for a quick few slashes.

The original appearance of the Mirror Shield was a star and a moon resembling the Islamic symbol, but this was changed in later releases to the Gerudo Symbol because of this reason.

This version of the Mirror shield is one of Link's Weapons (paired with the Master Sword) in Soul Calibur II. It caused opponents to take small amounts of damage whenever they hurt Link.

Majora's Mask
The Mirror Shield also appears in Majora's Mask, this time appearing as a hexagonal shield with a picture of an "unhappy face" upon it. This time, it is found Beneath the Well after bargaining with several Gibdo. Again, it can reflect light, is vital for getting through Ikana Castle and solving the few light puzzles in Stone Tower Temple.

Light directed from the Mirror Shield also has the ability to kill undead enemies such as Floormasters and ReDeads.

A mask in the shape of this incarnation of the Mirror Shield appears on the Happy Mask Salesman's backpack.

In the The Legend of Zelda: Collector's Edition version of Majora's Mask, the Mirror Shield causes a slight graphical error. When reflecting light, a green and black stripe slowly slides across the light-ray every second or so. This is probably a result of transferring the game to GameCube format.

Oracle series
The Mirror Shield also appears in these 2D games as the Level 3 shield upgrade. It has a blue sprite and can only be obtained on a linked game, via upgrading the shield through gameplay and using a password to upgrade it as well. These upgrades can be performed in either order. It creates a "pair" with the Master Sword from these games. However, it isn't that much different; it can block Twinrova's energy attacks, however.

The Wind Waker
The Mirror Shield again appears in the game, this time in the fifth dungeon, the Earth Temple. It is obtained by defeating three Stalfos; the mid-boss of the dungeon. It is the second - and final - shield of this game and automatically replaces the Hero's Shield once obtained.

Again, it is required to solve light puzzles, but occasionally, it must be paired with another light beam to successfully solve a puzzle, usually by utilizing Medli's harp, as it acts much, if not the same as the Mirror Shield does regarding light.

Light that bounces off the Mirror Shield can also paralyze certain enemies in this game such as ReDeads, is the only way to solidify Poes, and allow Dark ChuChu's to be turned to stone, unless these enemies walk under a light beam.

The Mirror Shield can also cause certain stone statues to break and reflect light along a large network of mirrors, as seen in the Earth Temple. The ability to break stone statues is needed to carry on past Floor 31 of the Savage Labyrinth.

The Minish Cap
After finishing the game, you can find Biggoron and let him eat your shield. If you return later, he will give you the Mirror Shield as compensation. It allows you to turn any projectile attacks into beams that shoot back at the enemy.

Theory
It is worth noting that the Mirror Shield cannot block Ganondorf's energy attacks, yet the Hylian Shield can. This is likely because the Hylian Shield gives Link a 'complete' appearance, which Nintendo probably wanted the player to use more often and specifically against his worst enemy, while the Mirror Shield gives Link a 'shiny, polished' appearance. Also, the Mirror shield in Ocarina of time seems to once have belonged to the Gerudos and might not work against Ganondorf because he is one of the Gerudos. Even though this is possible it would be kind of contradictive because of the fact that Twinrova, who also were Gerudo, only could be defeated by using the Mirror shield. Along the same vein, the Mirror shield cannot repel Deku attacks either.