De Bellis Antiquitatis or DBA (English: Of the Wars of Antiquity) is a fast play set of rules for the hobby of historical miniature wargaming, particularly ancient and medieval wargaming in the period 3000 BC to 1520 AD. Now in 3rd edition. These rules allow entire armies to be represented by fewer than 50 figures. The rules also include diagrams and over 600 army lists.

DBA traces its origin back to a two-page experimental set of rules by Phil Barker dubbed De Bellis Societatis Antiquorum that was demonstrated at the Society of Ancients (after whom these experimental rules were named) conferences for 1988 and 1989. Many rulesets at that time (including Phil Barker's WRG series of ancients rules) had added greater and greater detail regarding weapons and armor, movement and orders. Many gamers perceived that this increased complexity came at a cost in playability.

The De Bellis Societatis Antiquorum ruleset was designed as a "tonic for the jaded" with the goal of providing a fun, fast and challenging game and as an alternative to the WRG series of ancients rules. The first commercial edition of DBA was published in 1990, with Phil and Sue Barker and Richard Bodley Scott as its authors. The game has continued to evolve over the years; the most recent version was published in November, 2014 with just Phil Barker and Sue Laflin Barker as authors.