The 10 Rings are Sonic's and Tails' basic powerup. It acts as their equivalent to the Super Mushroom, due to their dependence on coins to take hits.

If Sonic or Tails have 10 or more rings, a different powerup will be given. They can receive this even when they already have a second-tier powerup active.

Powerups in Mushroom Kingdom Fusion
Mario Universe Super Mushroom | Fire Flower | Raccoon Leaf | Hammer Bros. Suit | Tanooki Suit | Blue Shell | Cape Feather | P-Wing
Sonic Universe 10 Rings | Fire Shield | Kevlar Shield
Arthur Universe Armor | Halo Armor | Sun Shield | Apollo's Shoes | Hermes' Shoes |
Exclusive Sci-Fi Suit | Mega Man Suit | Soldier Suit |
Other 1-Up Mushroom | 3-Up Moon | Poison Mushroom | Starman | Lifejacket | Reaper | Stomp Boots