Mass along with Energy, form the currency used in Supreme Commander 2, to build units and structures on the battlefield. Mass can also be used as a very powerful cripple to your opponent, because unlike Energy, which can be produced limitless with Energy Generators, which can be built anywhere on the battlefield, Mass can only be produced using the methods below.
Ways of accumulating MassEdit
There are four ways to accumulate Mass.
The most common method is via the use of Mass Extractors, which directly mine suitable physical matter from the planet's crust. Extractors can only be built upon the deposits marked on your map by your ACU's photoreceptors with the green hexagonal "Ma" iconography.
A secondary method of acquiring Mass is by Reclamation. When units and buildings are destroyed, their charred remnants leave behind residual Mass particles that can be collected by either an ACU or an Engineer via the Reclaim command.
The third way you accumulate mass is through your commander. Your commander, no matter the faction, naturally produces one mass. But if you are playing as the Illuminate, this can be increased to five with Mass Production research.
The final way to accumulate mass is to build Mass Converters, after researching Mass Conversion. You can then use Mass Conversion through the Special Commands interface with your Mass Converter, and convert 2500 Energy to 250 Mass per Mass Converter structure you have built.
(While organic and inorganic topography such as trees and rocks once yielded usable amounts of Mass and Energy, even the most mundane units of modern firepower are simply too demanding to make such ancillary extractions feasible.)