From Sonic Retro
The Chaos Rings are six powerful rings appearing in Knuckles' Chaotix. According to the Japanese manual, the Rings were created by an ancient civilization and infused with Chaos Emerald energy. Doctor Eggman builds a base on the mysterious island where they were created in order to find the Rings, which are hidden in Special Stages. Throughout the game, the Chaos Rings are collected in the same way as the Chaos Emeralds usually are, and having all six by the end rewards the player with the "good ending," featuring a picture of Sonic and Tails with the Chaotix.
The Chaos Ring storyline was largely unmentioned in the US manual, and instead Eggman was said to be trying to steal the "Power Emerald" from "Carnival Island". The Chaos Rings can still be collected, but are never explained.
During development these rings were known as the Holy Rings. They were renamed "Chaos Rings" by Knuckles' Chaotix prototype 0202. It is unknown why their names were changed, though it may have something to do with religious censorship employed by many video game publishers at the time.
|Items in the Sonic the Hedgehog Game Series|
|Collectibles||Ring | Red Star Ring | Emblem | Chaos Drives | Material|
|Power-ups||Shield (Water, Lightning, Fire, Gold) | Invincibility | Power Sneakers | Power Core | Light Cores|
|Level Objects||Monitor | Spring | Spikes | Checkpoint | Time Warp Plate | Signpost | Goal Ring | Giant Ring | Capsule | Button | Bumper | Speed Booster | Chao Container|
|Powerful Items||Chaos Emeralds | Super Emeralds | Master Emerald | Time Stones | Chaos Rings | Precioustone | Sol Emeralds | Jeweled Scepter | World Rings | Excalibur | Phantom Ruby|
|Weapons||Piko Piko Hammer | Chaos Energy Cannon | Caliburn | Wispon|
|Devices||Remote Robot | Combi Confiner | Mother Computer | Nega's Camera | Arks of the Cosmos | Miles Electric|
|Other||Chili Dog | Scepter of Darkness | Cacophonic Conch|