In Steel Goliaths, shields act as a temporary first line of defense for MIUs. Compared to their more permanent contemporary, armor, shields are designed to provide a barrier that either prevents or minimizes a Mech's chances of receiving damage. Upon activation, a set amount of relative effectiveness points is temporarily added to a Mech's total armor value. Unlike armor, which adds points of armor based on a Mech's weight, shields place a layer over the entire Mech. Shields are classified as either a light, medium, or heavy system and can add between one and seven points.
Not being a critical system, shields do not automatically activate when a Mech powers up. Despite this, the system can be turned on and off whenever the pilot chooses. For a shield to activate, a pilot must allocate at least the minimum power level required for the shield to turn on and wait an activation delay. The duration of a shield is based upon its power level, power consumption, and hits sustained in combat. While the former two are constant variables, hits taken in battle will drastically reduce a shield's power level, with the amount lost varying between weapons. As a shield weakens, weapons may begin to pass through it and hit the armor underneath, albeit with reduced damage. Once a shield deactivates, a cooldown/recharge period must be waited before it can be used again.
- In early development, shields were planned to use a "Five Point System," meaning that the shields would add one to five points. This was changed to a "Seven Point System" so the shields could have a clearer difference in their performance.