From the back of the book:

THE FUTURE OF WARFARE IS HERE!

Welcome to the 31st century, a time of endless wars that rage across the known universe. These epic conflicts are won and lost by BattleMechs, 30-foot-tall, humanoid titans of metal bristling with high-intensity lasers, rapid-fire autocannon and dozens of other lethal weapons; enough firepower to level entire city blocks. Your elite force of MechWarriors drive these juggernauts into battle, blasting at your opponent's 'Mechs in a deadly game of kill or be killed. Will they become instant legends, or forgotten casualties? Only your skill and luck will determine their fate.

Drawing on years of experience, this book combines the best of the BattleTech board game into a unified whole. BattleTech Master Rules is entirely restructured and streamlined; it is the same game, but like you've never seen it before. This book includes the complete game rules, a quick-and-easy scenario creation system, the Battle Value point system for evaluating 'Mechs and balancing forces, and revised and expanded miniatures rules.

User comment:

This was the default, complete ruleset for BattleTech at the time of printing, superceding the earlier BattleTech Compendium: Rules of Warfare. Again, no rules were included for AeroTech or BattleSpace units; this ruleset was dedicated to ground-based combat.

These rules were revised and re-issued several times. The original FASA edition was published in 1998, and was then substantially updated and re-issued as the FASA Revised edition in 2001, one of the last BattleTech sourcebooks produced by FASA.

In 2002, the BattleTech license was taken over by FanPro, and in 2003 they revised the Master Rules and reossued them as the Classic BattleTech Master Rules, Revised in a softback format, followed by a hardback edition in 2004.

The BattleTech: Master Rules were finally superceded when Fanpro released the first edition of Classic BattleTech: Total Warfare in 2006.