Mistakes happen, and sometimes players come up with situations the BattleTech designers, writers and testers never imagined. If you believe you’ve found a problem, report it in the appropriate thread on our forum.  Catalyst rolls in all approved errata every time a product is reprinted.

Below is all official errata issued for our products. Some of the errata below is for a specific printing of a book.  To determine what printing you have, check the last page of the credits section.  If it’s any printing past the first, this will be noted on that page (e.g. “Corrected Fifth Printing”).

Errata last updated 4 September 2019.


Core Rule Books


BattleMech Manual Errata version 2.1

This PDF is 348KB.
In addition, there is one other download for the BattleMech Manual. This corrects the 1st printing’s flawed flowchart on page 42:

BattleMech Manual Corrected Damage Flowchart p. 42


Total Warfare Errata version 5.1

Total Warfare 5th Printing

This PDF is 674KB.

TechManual Errata version 3.1 – General Changes

This PDF is 816KB.

In addition, there are two other downloads for TechManual. The first replaces pages 302-314 as well as page 319, the second replaces pages 349-352. Both are featured in the most recent TechManual release, but are released here separately for your convenience.

TechManual Errata version 3.0 – Battle Value (Dec 2017)
TechManual Errata version 3.0 – Infantry Weapon Tables (Dec 2017)


Tactical Operations Errata version 3.02

In addition, there is one other download for Tactical Operations, for all printings, which adds landing modifiers for the various types of special terrain found in that book:

Tactical Operations Landing Modifiers


Strategic Operations Errata version 3.01

This PDF is 362KB.
In addition, there is one other download for Strategic Operations, for the first and second printings, which replaces the Customization rules found on pp. 188-189:

Strategic Operations Revised Refitting


Interstellar Operations Errata version 1.1

This PDF is 296KB.

A Time of War Errata version 2.02

This PDF is 158KB.


Alpha Strike Errata version 2.4

This PDF is 516KB.

The above link is for those who own the first printing. Below is an alternate version of this errata for those of you who own the most current printing of Alpha Strike (the second). This document removes all errata already corrected in the second printing, making it much smaller and easier to use:

Alpha Strike Errata version 2.4 (Second Printing)


Alpha Strike Companion Errata version 1.2

This PDF is 326KB.

In addition, there is one other download for the Companion, which clarifies the heat conversion process:

Alpha Strike Companion Converting Heat Errata version 1.1