The following are some mistakes and oversights known to have been made by players unfamiliar with Supreme Commander.

These are misunderstandings relating to the game interface and not strategic or tactical blunders.

• Though it is not displayed on the build menu by default, T2 and T3 engineers can build the same buildings as their lower tech equivalents - these additional build options may be reached with the tech level buttons to the left of the build menu.
• Mass extractors can be upgraded without having to reclaim them and replace them with higher tech levels. When a mass extractor is selected, the option to upgrade it appears in the build menu.
• Tech 4 or 'experimental' units are not constructed by Tech 4 factories - tech 4 factories do not exist. Instead, experimental units are constructed by Tech 3 engineers, and must be placed at a specific build location in the same manner as buildings. Experimental unit build options may be reached from the tech level buttons on the left hand side of a T3 engineer's build menu.
• Engineers can only build one type of Cybran shield generator available, which is small and weak. However, this can be upgraded to cover more area and project a stronger field by selecting the shield, and choosing the upgrade option.
• It is never a bad idea to reclaim any wreckage or decor if you don't have anything to do, as not only does it keep your pc from lagging, but you could, even with a great economy, reclaim experimental units to make more of your own, as well as deny your opponent the wreckage.