The Rainbow Drop is an item in Dragon Quest and Dragon Quest III. It is used to create a bridge between the southeastern and south central continents in Alefgard. It is required in order to reach Charlock Castle in both games. Due to text restrictions in the Gameboy Color remake of Dragon Quest, Rainbow Drop was renamed Rainbw Drp.
In order to acquire the Rainbow Drop in both games, the player must bring the Staff of Rain and the Stones of Sunlight to the Southern Shrine. The old man in the shrine will combine the items and give the player the Rainbow Drop.