"The Dying Earth" is an "important" book historically as it is the source inspiration for the early Dungeons and Dragons magic system (some of the spells are clearly copied from it).
As an aside, I've had the good fortune to play in a few "Dying Earth" roleplaying campaigns (https://en.wikipedia.org/wiki/The_Dying_Earth_Roleplaying_Ga...) and it's one of the most fun RPGs as most of the gameplay revolves around one-upping everyone else and experience is awarded for using taglines appropriately rather than killing monsters etc.
As an aside, I've had the good fortune to play in a few "Dying Earth" roleplaying campaigns (https://en.wikipedia.org/wiki/The_Dying_Earth_Roleplaying_Ga...) and it's one of the most fun RPGs as most of the gameplay revolves around one-upping everyone else and experience is awarded for using taglines appropriately rather than killing monsters etc.