Act Rings are slightly smaller than Giant Rings. They float in midair and have a black center with a number from one to three inside them.
Three Acts Rings can be found inside each Zone Map in Sonic Advance 3. Upon being touched, the playable characters will disappear briefly and the player will begin the Act of that Zone corresponding to the number in the Act Ring. Upon completing an Act, a little golden crown will appear above its Act Ring. Chaos Angel's Zone Map also features a large metallic Act Ring with a red Eggman Empire decal on it that leads to Altar Emerald.