Final Fantasy VII · PlayStation · 1997
By equipping the W-Item materia and cancelling out of the second item selection during battle, the game duplicates the first selected item — allowing infinite copies of rare consumables like Megalixirs.
The W-Item materia allows a character to use two items in a single turn, but a flaw in its selection logic means that cancelling after selecting the first item but before confirming the second causes the item count to increment by one rather than decrement. Repeating the cancel action fills the inventory with copies of the first selected item at no cost. The glitch is not strictly an Easter egg — it is a programming oversight — but it became one of the most famous secrets in Final Fantasy VII because of its practical power: players could duplicate Megalixirs (which fully heal the entire party), Hero Drinks, and other rare consumables that would otherwise require grinding to obtain. The discovery circulated through gaming magazines and early internet FAQs within months of the game's Western release.
Equip the W-Item materia on a party member. In any battle, select W-Item and choose the item you want to duplicate as the first item. Begin selecting the second item, then press the cancel button before confirming. The first item's quantity will increase by one. Repeat the cancel action to duplicate the item as many times as desired.