The Erdrick Trilogy refers to the first three games in the main Dragon Quest series. These titles share a similar setting and timeline, and feature a recurring theme of a bloodline chosen by divinity to repel diabolical forces that want to conquer the kingdom of Alefgard. The eponymous series takes its name from Erdrick, the original savior of the land.
Dragon Quest III is chronologically the first game in the trilogy. It tells the story of the Hero of Aliahan following in their late father's footsteps to free their native homeland from the threat of Baramos, engaging in a globe-spanning journey across a world based on our very own during the Age of Exploration. Upon saving the world from Baramos and being honoured by the King of Aliahan, the Hero is threatened by the archfiend Zoma, Lord of the Underworld and master of Baramos who intends to finish what his minion failed to do by dragging the world into darkness. The Hero is warned of the danger of facing Zoma by the Dragon Queen, who bequeaths a Sphere of Light to pierce the shadows protecting the tyrant.
Upon descending to the underworld to confront the archfiend and landing near the castle town of Tantegel, the Hero gathers incredible gear to face Zoma with and crosses a bridge of rainbows to reach his citadel. After vanquishing the devil, the Hero is hailed as the realm's savior by the King of Alefgard and is granted the highest honour through the title of Erdrick, which means "dwelling-land" in the ancient tongue. The Hero is trapped in the underworld when the cleft between worlds closes, siring a lineage to defend the realm from evil.
Dragon Quest tells the story of a descendant of Erdrick being summoned by King Lorik of Tantegel to defeat a new evil foe who has plunged Alefgard into chaos, the Dragonlord. The new Hero follows in his fore-bearer's footsteps and must regain their equipment in order to defeat the Dragonlord, rescue the kidnapped Princess Gwaelin, and retrieve the stolen Sphere of Light. Upon his victory, the Hero and Princess Gwaelin leave Alefgard to explore the wider world and found new kingdoms on foreign shores. The amount of time between Dragon Quest III and Dragon Quest is left up to the player's imagination, though it is implied to take place approximately sixteen generations later through King Lorik XVI's status as the sixteenth descendant of the original king of Alefgard.
Dragon Quest II takes place a century later and begins with a demonic siege on the kingdom of Moonbrooke, one of many kingdoms founded by the hero of Dragon Quest, by the mad priest Hargon and his apocalyptic cult. In response, the Prince of Midenhall is sent by his father to join forces with his cousins to stomp out the mad man's ambitions. The Prince of Midenhall, the Prince of Cannock, the Princess of Moonbrooke, and in the HD-2D remake the Princess of Cannock, travel together throughout the greater world surrounding Alefgard, saving villages and towns from the cult's invasions before attacking the heart of evil in the frozen plateau of Rendarak. The HD-2D version of the game confirms the trilogy's span of time suggested by King Lorik's proper title in the secret ending, where a descendant of an important character states she is the eighteenth of her line.
