DBA is much like DBM however it is designed for smaller battles (still 25mm or 15mm scale but fewer troops on the table).

DBA is designed for fast play, and a game can be played to its conclusion in under an hour (or less if the two generals are familiar with the rules).

There are fewer troop options than DBM and the rules are a bit slimmer but it manages to do this without loosing the feel of DBM.

We have played a few mini-tournaments of DBA on club nights with Brian and Jim's DBM forces split into several smaller DBA armies.