Scattered around each level are gold rings. Collecting 100 rings rewards the player with an extra life. Rings act as a layer of protection against hazards: if Sonic holds at least one ring when he collides with an enemy or dangerous obstacle, all his rings will scatter. He can recollect some of them again before they disappear. If he is hit without holding any rings, he loses a life. Shields and temporary invincibility can be collected to provide additional layers of protection, but certain hazards, such as drowning, being crushed, falling into bottomless pits, or running out of time, kill Sonic regardless of rings or other protection.