Pieces of Six: Massed Battle Rules

From publisher blurb:

Pieces of Six is an advanced rules supplement that allows you to run massed battles, using standard character write-ups, and without needing to manage dozens of figures! Each miniature represents a Unit of troops that share a common Archetype.

Complete rules for scaling up your combats for dozens or hundreds of troops.
Works for any genre – ancient, fantasy, modern, sci-fi, and more.
Includes two sample forces, each with three Unit types and an NPC General.
A two-page sample War Map gives you a proving ground for experimental battles.
Also comes with a separate Army Record Sheet.