The Shield Charge can be seen on the game's HUD in the lower left corner of the screen, right above the Unleashed Gauge. It presented as a horizontal row of a number of cyan ovals (named Shield points).
In the Xbox 360/PlayStation 3 version of Sonic Unleashed', the Shield Gauge determines when the player is able to use Guard effectively. As long as the Shield Gauge has some energy, the player can successfully use Guard to put up a shield. Every time Sonic is hit by an enemy's attack that the player successfully blocks with Guard, the Shield Gauge is consumed, which is signified by one or more of the Shield points losing color, with the amount of energy consumed being proportional to the blocked damage; in other words, the stronger the blocked attack is, the more energy in the Shield Gauge is consumed. If the Shield Gauge completely runs out, Guard is no longer effective and cannot block an attack.
The Shield Gauge automatically replenishes itself over time, albeit at a slow rate, but it can also be fully restored immediately by collecting a Shield Charge. At the beginning of the game, the Shield Gauge has five Shield points, but the player can increase the Shield Gauge's size by leveling up Sonic the Werehog's Shield parameter. For each level increased, the Shield Gauge increases by one Shield point until it reaches the upper limit of fifteen Shield points.
- In the early development of Sonic Unleashed, the Shield Gauge was designed as a completely blue bar, rather than being composed of several ovals and had the word "SHIELD" written in yellow at the left end of the gauge.
- Sonic the Fighters also had a Shield Gauge for combatants which granted a limited number of shields they can use when blocking attacks.