Targeting
The Targeting System is a combat and environment interaction interface that locks Link's focus onto a single enemy or other target with a press of the either the Z or L Button in 3-dimensional Zelda games. Up until the release of the Nintendo 64, all Zelda games were 2-dimensional games with a clear view of all the action on the screen. In order to incorporate an easy battle system into a 3-dimensional game, something different had to be done to make combat more manageable and less frustrating.
Z-Targeting
Ocarina of Time marked the beginning of Z-Targeting. Once an enemy is Z-Targeted, Navi flies to the selected enemy and all of Link's attacks are directed at the targeted enemy. Navi can give Link useful information about enemies that are targeted. Z-Targeting helped make Ocarina of Time a success, and the interface was carried over to Majora's Mask (with the help of a new Fairy, Tatl) and the Wii version of Twilight Princess.
L-Targeting
The layout of the Nintendo GameCube controller lacks a conveniently located Z Button. In order to carry the popular targeting system over to the Gamecube, the button used for targeting was switched from Z to L. Implementation is the same, but with a different button. The L Button is used in the GameCube titles The Wind Waker and Twilight Princess. It was also used in the GameCube re-releases of Ocarina of Time and Majora's Mask as well as the 3DS remake of the former, as the 3DS lacks a Z button whatsoever.
Trivia
- In Ocarina of Time and Majora's Mask, Link can only target with the help of a fairy (for example, during the battle with Ganondorf in Ocarina of Time, Link cannot target him as he drives Navi away). In Majora's Mask, targeting is achieved with Tatl. However, the Wind Waker and Twilight Princess incarnations of Link do not require any assistance to target objects. This is never sufficiently explained in any of the games.