Short answers, pulled from the story.
Dragon Quest was created by game designer Yuji Horii, character designer Akira Toriyama, and composer Koichi Sugiyama. The first game was released in Japan on the 27th of May, 1986, and reached North America in August 1989 under the title Dragon Warrior.
The name Dragon Warrior was used in North America to avoid a trademark conflict with the tabletop role-playing game DragonQuest, published by Simulations Publications and later TSR, Inc. Square Enix did not register the Dragon Quest trademark in the United States until the 23rd of July, 2002. Dragon Quest VIII, released in 2005, was the first game in the series to use the Dragon Quest name outside Japan.
As of March 2022, the Dragon Quest series has sold over 85 million copies worldwide. The series had already sold 10 million copies by 1990 and 15 million by 1993. Dragon Quest III alone sold 1.1 million cartridges in Japan within a single day in 1988.
The Slime is the official mascot of the Dragon Quest series. It was designed by Akira Toriyama as a small blue water-droplet-shaped blob with a face, and it appears in every Dragon Quest game. Yuji Horii cited the Slime as an example of Toriyama's skill, saying it took artistic power to transform a pool of slime into a great character.
Dragon Quest is credited as the most influential role-playing game of all time by GameSpot, with nearly all Japanese RPGs drawing from its gameplay. Dragon Quest V's monster recruiting mechanics influenced Pokemon, Digimon, and Dokapon. Dragon Quest IV's AI tactics system is considered a precursor to Final Fantasy XII's Gambits system, and Dragon Quest III's class-changing mechanic shaped the Final Fantasy series.
On the 27th of May, 2026, Yuji Horii and executive producer Yosuke Saito announced that Dragon Quest XII: The Flames of Fate had been halted and its development restarted entirely from scratch. The new version was unveiled under the title Dragon Quest XII: Beyond Dreams. It will be the first mainline Dragon Quest title released after the deaths of composer Koichi Sugiyama and character designer Akira Toriyama.