Editing BattleTech (section)

=== Expansions ===
The game's popularity spawned several variants and expansions to the core system, including ''[[CityTech]]'' which fleshed out urban operations, infantry, and vehicle combat, ''[[AeroTech]]'' which focused on air and space-based operations, and ''[[BattleSpace]]'' which detailed large spacecraft combat.  FASA also published numerous sourcebooks, known as Technical Readouts, which featured specifications for new combat units that players could select from.  However, despite the large number of such pre-designed BattleMechs, vehicles, aerospace units and other military hardware, the creators also established a system of custom design rules, enabling players to generate their own units and field them in combat. In addition to game rule books, FASA published several background books detailing the history, political and social structures of various factions in the game, including all five Great Houses of the Inner Sphere, ComStar, the Periphery states and the fallen Star League.

FASA launched two additional systems to complement the core game: ''[[BattleTroops]]'', an infantry combat system, and ''[[BattleForce]]'', a large-scale combat simulator governing the actions of massed ''BattleTech'' units.  ''[[The Succession Wars]]'', a board game released in 1987, is one of only two purely strategic titles of the series (the other being "The Inner Sphere in Flames" from the Combat Operations book).  ''The Succession Wars'' is played on a political [[star map]], with players trying to capture regions of space.

Recent years have seen a trend of consolidating the expansions into "core products" for efficiency.  Beginning under FanPro's aegis, then continued under Catalyst Game Labs, the various rulesets have been combined into a series of Core Rulebooks:<ref>{{cite web |url=http://bg.battletech.com/books/core_rulebooks/ |title=Core Rulebooks {{pipe}} BattleTech: The Game of Armored Combat |date=October 26, 2011 |access-date=October 14, 2014}}</ref>

*'''Total Warfare''' (TW) integrates the original boardgame with ''CityTech'', ''BattleTroops'', and parts of ''AeroTech 2'' (itself a consolidation of ''AeroTech'' and ''BattleSpace'') pertaining to atmospheric operations (such as simplified rules for Dropship operations, and the use of AeroTech Fighters in atmospheric combat).
*'''Tactical Operations''' (TO) supplements ''Total Warfare'' with rules for expanded game-play (advanced rules).  These include an expanded weapons / equipment table listing (Lostech), advanced unit types (such as "mobile structures", planetary fortresses, and "large support vehicles") as well as numerous optional gameplay enhancements for planetary-level conquests (consolidating ''Maximum Tech'' and other expansion packs, like ''Explorer Corps'').
*'''Strategic Operations''' (SO) consolidates the rules for multi-game campaigns within a single star system (such as unit morale and management, repair and maintenance, equipment salvage, in-game construction, and unit-level economics) with the remaining ''AeroTech 2'' rules omitted from TW.  These include the introduction of [[Capital ships|capital-level]] spacecraft (Jumpships / Warships / Space Stations / Fighter Squadrons) and equipment, [[Space warfare in fiction|space warfare]] rules, and the use of space travel as a gameplay element.  A revised version of ''BattleForce'' is also consolidated into the book.
*'''TechManual''' (TM) consolidates the customization rules with [[Fluff (fiction)|technical fluff]] from various products for units compliant to ''Total Warfare'' rules.  (Construction rules for the missing units are listed in TO or SO, as these units are not considered to be "tournament legal" for gameplay).
* '''Interstellar Operations''' (IO) was originally a project that had been available in beta form. The book was designed to introduce rules for faction-wide operations (such as entire Clans / Succession Houses / Empires) across multiple campaigns and star systems—up to and including the entire Inner Sphere.  The book itself would have also included an expansion of additional technologies which stipulated per time period in the game universe's history, including revised rules for more advanced types of vehicles such as Land-Air 'Mechs, Superheavy BattleMechs, and unique period technologies. The size of the materials slated for the book forced its splitting into two volumes; the second, which was initially known as the ''Campaign Companion'', was renamed.<ref>{{cite web |url=http://bg.battletech.com/news/battleblog/interstellar-operations-open-beta-test-begins/ |title= Interstellar Operation Open Beta Begins |publisher=Catalyst Game Labs |date=November 2, 2012 |website=Battletech News |access-date=October 14, 2014}}</ref><ref>{{cite web |url=http://bg.battletech.com/test/core-rulebooks/interstellar-operations/ |title= Interstellar Operation |publisher=Catalyst Game Labs |date=November 2, 2012 |website=Battletech News |access-date=July 23, 2015}}</ref>
* '''Campaign Operations''' (CO) is the self-contained companion book to Interstellar Operations. The book provides core rules handling player campaigns, using different rules sets. Taking older legacy rules found in previous source books, CO presented them in a singular core rulebook for better accessibility for the player. Included in the publication are rules to build environments for players to create and maintain combat units to be played in the game universe and rules allowing them to design their own worlds and star systems if desired.<ref>{{cite web |url=http://bg.battletech.com/test/core-rulebooks/campaign-operations/ |title= Campaign Operation|publisher=Catalyst Game Labs |date=July 2, 2016 |website=bg.Battletech.com |access-date=July 2, 2016}}</ref>
*'''BattleMech Manual''' is an alternative Core Rulebook to Total Warfare. Unlike Total Warfare, the Battlemech Manual ignores all elements of combined operations, instead presenting concise and developed rules for playing games of Battletech focused exclusively on BattleMechs fighting against Battlemechs. The book is marketed as "table usage friendly" <ref>{{cite web |url=https://store.catalystgamelabs.com/products/battletech-battlemech-manual-book-pdf-combo/ |title= BattleMech Manual|publisher=Catalyst Game Labs |date=July 2, 2016 |website=bg.Battletech.com |access-date=July 2, 2016}}</ref> and serves as a complete, standalone game experience for players who want a single book for Mech focused combat.