Collecting all seven Chaos Emeralds is the primary side quest in Sonic the Hedgehog 2. These powerful gems are obtained by successfully completing Special Stages. To access a Special Stage, you must pass a Star Post with at least 50 rings. Once you hit the Star Post, a ring of stars will appear above it, indicating you can jump into it to enter the Special Stage. There are a total of 7 Special Stages, and each one rewards you with a Chaos Emerald upon completion. Successfully collecting all seven unlocks the Super Sonic transformation, a game-changing ability.

Why Collect Them?
- Super Sonic: The main reward. Super Sonic is invincible (except to crushing or drowning), much faster, and jumps higher. He consumes rings over time, so you need to keep collecting them to maintain the form.
- True Ending: Collecting all seven Chaos Emeralds is required to see the game's true ending after defeating Dr. Robotnik.
- Challenge: Special Stages offer a unique and challenging gameplay experience distinct from the main levels.
Prioritize collecting rings in each act to ensure you have enough to enter Special Stages. If you fail a Special Stage, you can try again in a later act or zone, as long as you find another Star Post with 50+ rings.