In most "Sonic" games, the goal is to collect the Chaos Emeralds; the player is required to collect them all to defeat Eggman and achieve the games' good endings. "Sonic" games that do not feature the Chaos Emeralds, such as "Sonic CD", feature different collectibles that otherwise function the same. Players find the Emeralds by entering portals, opening portals using 50 rings, or scouting them within levels themselves. Sometimes, the Emeralds are collected automatically as the story progresses. By collecting the Emeralds, players are rewarded with their characters' "Super" form and can activate it by collecting 50 rings in a stage. The Super transformations grant the player character more speed, a farther jump, and invincibility, but their ring count drains by the second; the transformation lasts until all the rings have been used. Some games require the player to collect all the Chaos Emeralds to reach the final boss.