Water of Life

The Water of Life is an item that restores life. It first appears in The Legend of Zelda & makes a second appearance in The Adventure of Link, where it served a different role.

The Legend of Zelda
The Water of Life in The Legend of Zelda completely restores Link's energy. It is sold by various Old Women who appear in caves. Before Link can buy it, he needs to get the Letter from an Old Man. Prior to showing the Letter to one of these Old Women, Link will find caves with silent Old Women standing by 2 flames. These are the caves where the Water of Life is sold. Once he shows the Letter to an Old Woman in any of these caves for the first time, they will present the Water of Life for sale. The Water of Life replaces the Letter in his Inventory every time Link purchases it. When he uses it up, the Letter reappears in the Inventory. There are two types of the Water of Life that are sold by the Old Women in these caves:

Blue Water of Life
The Blue Water of Life is sold by the Old Women in the caves for 40 Rupees. It completely restores Link's life meter and is thus consumed.

Red Water of Life
The Red Water of Life is sold by the Old Women in the caves for 68 Rupees. It completely restores Link's life meter and then turns into the Blue Water of Life, meaning that it gives Link 2 uses before being completely consumed. If Link already has a Blue Water of Life in his Inventory & buys another Blue Water of Life, it will turn into a Red Water of Life.

The Adventure of Link
The Red Water of Life returns in The Adventure of Link, where Link finds it in a cave in the Moruge Swamp. However, instead of restoring Link's health, it is instead given to an Old Woman in the Harbor Town of Mido who has a sick daughter. In exchange, she invites Link inside her house where an Old Man teaches him the Fairy Spell.