In the classic Sonic the Hedgehog games, how many rings give you an extra life when collected?

How to get close to this number

Extra-life thresholds in games of that era are almost always round numbers that feel achievable within a level but not trivially. A hundred is the canonical choice across the medium, and if a game rewards a collectable count, a hundred is the answer before you know the game.

The dual function in the explanation is the design insight: rings are both the life currency and the health bar. Being hit scatters them instead of killing you, so the same resource that earns extra lives is the thing protecting the life you have. One collectable doing two jobs is elegant, and it is why the games feel forgiving despite being fast.

That design also creates the series' signature tension. Holding a large ring count means safety and progress toward a reward, and losing them all in one hit means both are gone at once — so the player is always carrying something they are afraid to lose. Very few games make a counter feel like a possession, and this one does it with a single rule.