Short answers, pulled from the story.
Dungeons & Dragons was created by Gary Gygax and Dave Arneson and first published in 1974 by Tactical Studies Rules (TSR). The game grew from Arneson's medieval wargaming campaigns and Gygax's expansion of the Chainmail miniatures ruleset.
By 2004, more than 20 million people had played Dungeons & Dragons and consumers had spent over a billion dollars on D&D products worldwide. In 2017, Wizards of the Coast reported 12 to 15 million players in North America alone, the most in the game's history at that time.
TSR introduced both versions in 1977. The Basic Set was a simplified, toy-store-friendly edition aimed at newcomers, while Advanced Dungeons & Dragons was a more structured, rules-heavy system for experienced hobbyists. The two lines developed separately until Wizards of the Coast merged them into a single unified game with the 3rd Edition in 2000.
Some Christian groups and parents claimed the game promoted devil worship, witchcraft, suicide, and murder. High-profile cases, including the disappearance of James Dallas Egbert III and the conviction of Chris Pritchard for murdering his stepfather, fueled the controversy. Research by psychologist Armando Simon and others found no harmful effects linked to playing D&D, and the notoriety paradoxically boosted sales through increased public awareness.
Gary Gygax listed key influences in Appendix N of the original Dungeon Master's Guide, including J.R.R. Tolkien, Robert E. Howard, H.P. Lovecraft, and Fritz Leiber. The D&D magic system came from Jack Vance's Dying Earth stories, the original alignment system derived from Poul Anderson's Three Hearts and Three Lions, and specific items such as the vorpal sword originated in Lewis Carroll's "Jabberwocky."
In January 2023, a leaked draft of OGL 1.1 revealed Wizards of the Coast planned to impose royalties and revenue reporting on third-party publishers, and would no longer authorize the original OGL. The backlash included a boycott of D&D Beyond and mass subscription cancellations. On the 27th of January 2023, Wizards announced that System Reference Document 5.1 would be released under an irrevocable Creative Commons license (CC BY 4.0) and pledged not to deauthorize the original OGL 1.0a.