Giant Ring

A Giant Ring at the end of Green Hill Zone Act 1 in Sonic the Hedgehog (16-bit).

Giant Rings (also known as Warp Rings) transport the player to a Special Stage in early Sonic games. They have had other uses besides that as well.

Sonic the Hedgehog (16-bit)

In the original Sonic the Hedgehog a big Ring (大きなリングMedia:Sonic1_MD_JP_manual.pdf ōkina ringu) appears at the end of a Zone's Act 1 or Act 2 if the player has 50 or more Rings. Jumping into one will take the player to a Special Stage for a chance to attain a Chaos Emerald. They appear in all Zones except Scrap Brain Zone and Final Zone.

Strangely, they aren't mentioned at all in the game's US manual.

Sonic the Hedgehog CD

The big Ring (大きなリングMedia:SonicCD_MCD_JP_manual.pdf ōkina ringu), now known as a Special RingMedia:SonicCD_MCD_US_manual.pdf in the US, returns in Sonic the Hedgehog CD, serving the same function it did in Sonic the Hedgehog. A Special Ring appears at the end of a Round's Zone 1 or Zone 2 if the player has 50 or more Rings. Jumping into one will take the player to a Special Stage for a chance to attain a Time Stone.

Sonic 3 & Knuckles

The Special Ring reappears in Sonic 3 & Knuckles. It transports the player to a Blue Sphere Special Stage. If the player is in the S&K zones of Sonic 3 & Knuckles and has collected all of the Chaos Emeralds, it becomes a flashing Super Ring that will transport them to the Hidden Palace Emerald Shrine, where they can select which Super Emerald to try to collect. If the player has already collected all the Chaos Emeralds (or Super Emeralds) in the game, the giant Ring will give them 50 Rings when collected.

Sonic 3D Blast

In Sonic 3D Blast, there are Giant Rings over transport tubes and the goal. You need to throw all the Flickies in the area into the ring to warp them to their dimension. Once done, the ring will disappear and the path will open.

Sonic Blast

The Sonic Blast giant Rings, although almost as small as regular Rings, but thicker, have the same function as those in S3&K. Unlike S3&K, where Special Stages alternate by the order you enter, you will always get the same special stage from the same zone. Also unlike S3&K, there's only one giant Ring per level.

Sonic Chaos

Not a transport feature, these oversized rings appear inside the first special stage and are worth 10 standard Rings each. A similar item crops up in the night levels of Sonic Unleashed, where larger, thicker rings are worth 10.

Knuckles' Chaotix

In Knuckles' Chaotix, not only are there Giant Rings at the end of an act which appear with 50 Rings and will take you to the Special Stage, there are also Giant Rings scattered around the level which will transport the player to the game's Bonus Stage.

Sonic 4

Sonic the Hedgehog 4 takes cue from Sonic 1 and Sonic CD. Giant Rings appear at the end of every Zone's first three Acts, allowing access to the Special Stage provided Sonic has at least 50 rings in hand. Unlike previous games however, when all the Chaos Emeralds are collected, they won't appear after collecting 50 rings, as they can be accessed from the Level Select screen.

Sonic Mania

The Giant Rings in Sonic Mania act similarly to the ones from Sonic 3 & Knuckles. They appear as three-dimensional, polygonal rotating rings, as opposed to the sprite-based rings of the classics. They are found hidden throughout the zones, and when entered, transport the player to a Special Stage. After the Special Stage is cleared, the ring that was entered becomes wire-frame and can no longer be entered until the player completes the game and revisits the zone through a completed save file. In addition, the giant ring cannot be entered in Time Attack mode or Competition mode. If all Chaos Emeralds are collected, the giant Ring will give 50 Rings when collected.

3D Sonic Games

These games don't use them in the way the Genesis games do. Instead, they act as Signposts in the form of Goal Rings.