From publisher blurb:
Sometimes the smallest creatures are the pose the biggest danger, especially when they gather in massive numbers. The Black Guard, in both its ancient and modern incarnations, know this fact well from dealing with swarms of foes.
Compatible with any d20 system, included within are four of the most dangerous swarms faced by the Black Guard from the fiendish Sekeja to the draconic Thunderdrakes, from the savage Razorfish to the scuttling Skeleton swarm.
Also within are two diabolical traps that incorporate swarms into their designs.
But the Black Guard is not without their methods of dealing with swarms of fearsome creatures. Two feats and a magic item specifically designed to deal with this type of opponent are included to help level the playing field for characters.