DBACW is an expansion for the WRG De Bellis Antiquitatis rules version 2.0 adapting the DBA mechanics to the American Civil War. Ownership of the DBA rules are required.

While the system is designed as an expansion to DBA, there are grades for troop types ("Veteran", "Experience", and "Raw") and Generals ("Good", "Average" and "Poor"), which is more similar to De Bellis Multitudinus (DBM). A typical army is a division composed of multiple brigades (each of which has its own commander). Rules are also given for larger battles forming Corps sized units.

Scale:
Infantry element: 4-500 men
Cavalry element: 3-400 men
Artillery element: 8-12 guns
Ground scale: 1" = 100 paces (about 80 yards)