"The Wind Dukes of Aaqa are the legendary creators of this artifact. It is said that they constructed the Rod to use in the great battle of Pesh where Chaos and Law contended. There, the Rod was shattered and its parts scattered, but the enchantments of the item were such that nothing could actually destroy it, so if its sections are recovered and put together in the correct order, the possessor will wield a weapon of surpassing power."
-AD&D, Dungeon Masters Guide
During 2nd Edition AD&D (1996), TSR put out an epic boxed set adventure the aptly named The Rod of Seven Parts. This quest is quite simply to recover the pieces of the Rod before the Queen of Chaos' agents in order to prevent Chaos overtaking all of Oerth (or whichever game world used). Anyone who has read Michael Moorcock's Elric series knows how high the stakes are here.
This is fun part. In conjunction with the adventure, Dragon #233 published an article by Skip Williams (who also wrote the adventure) titled Game Wizards: The Rod of Seven Parts. The article is smart overview of where to place the different chapters of the adventure in established worlds such as Greyhawk, Forgotten Realms, Planescape, etc. Spoiler alert, the climatic chapter of the adventure involves Chaos waves changing the face of the world with which the PCs must contend. The suggested Chaos effects are truly the delicious part of this article that you won't find in the boxed set.
"Specific chaos effects could include:
- The transformation of the Nyr Dyv into a dense forest. The Rhennee now roam the area in caravans of wagons. The Nyr Dyv remains a dangerous place full of hidden canyons where huge serpents lurk. Enclaves of other dangerous monsters are scattered throughout the forest
- The flooding of the Sea of Dust, which becomes a shallow sea of salty, polluted water.
- The transformation of the Azure Sea into a sea of tall grass where caravans of elephants make their way to the Pomarj and the Iron hills from the depths of the Hepmonaland Jungle, which becomes known for its verdant purple trees and venomous, flying reptiles."
Skip only gave three examples but you get the idea here. By using this type of world spanning Chaos effect (Rod story or not) an aspiring DM can mold Greyhawk's very familiar map into anything you can imagine! This sort of alien landscape will surely throw players out of their comfort zone and make them eager to "save the world" by getting the Rod to counter or destroy whatever source of Chaos magic is causing the changes.