Anatomy of a Game: Zelda IV - Telebunny.net

On how Zelda works.

The level nudges you more and more overtly to find the White Sword — subtly at first, but eventually outright asking you, “Hey, did you find the White Sword?” You need to have five hearts to equip the White Sword, which means that if you’ve been clearing the dungeons in order, you can upgrade that pitiful little Wooden Sword to something twice as powerful even if you haven’t found any free-range Heart Containers to beef up your health.