The broken sword

Michael Moorcock has credited Poul Anderson's The Broken Sword as an influence on Elric: a doomed hero bound to a cursed, soul-drinking black sword, in a world of chaos and fading elder races where the gods are indifferent.

Influenced Cook's darker, morally ambiguous approach to fantasy. Helped move away from the clear good-versus-evil morality common in earlier fantasy.

Gary Gygax lists it in Appendix N of the 1979 Advanced Dungeons & Dragons Dungeon Master's Guide, his published list of the fiction that shaped the game. Poul Anderson is listed for three books, The Broken Sword among them. Its cold, amoral elves and trolls, drawn from Norse saga rather than from Tolkien, fed the game's darker picture of the fey. ​Law vs. Chaos: Anderson's core worldview (developed in Three Hearts and Three Lions and The Broken Sword) directly birthed D&D's entire Alignment System.

Anderson wrote a saga rather than a novel about one, and the borrowings are structural:

• A sword broken and reforged as the hinge of the plot, which is Sigurd's Gram
• A blade that must kill whenever it is drawn and turns on its owner, the Tyrfing curse
• A changeling, a doomed hero raised away from his kin, and incest discovered too late, all of which the Volsungs supply
• The saga voice itself: flat, fast, fatalistic, and offering no interiority

Published the same year as The Fellowship of the Ring and drawing on the same Norse source Tolkien taught, which is why the two books read as opposite answers to one question.