BattleTech (or "BT") is a science-fiction tactical wargame in which players battle one another with various war machines. The heart of the game is the "BattleMech": a giant fighting robot; typical games have each player controlling from 1-4 'Mechs. Vehicles, infantry, power armour, aircraft and other unit types also exist. The game system includes details such as varying weapon ranges, heat generation, and discrete hit locations (torso, arms, legs, etc.). 'Mechs vary greatly by mobility and firepower, and players can choose from provided designs or take the time to create their own 'Mechs from scratch. The game is typically played on one or more mapsheets or mounted map boards; optional rules are also available for hexless play. An extensive line of pewter figurines ('Mechs, vehicles, and the like) are available from Iron Wind Metals. (Many earlier BattleTech figures were produced and sold by Ral Partha, which still handles the figure line in Europe.)
The main component of the current generation of BattleTech is a series of core rulebooks, the central one being Total Warfare, which contains the main rules for the game (the 2018 reprint is up-to-date in terms of errata fixes). TechManual contains construction rules for 'Mechs and other units, for those who want to create their own custom units. A series of four advanced rulebooks expands the game in many different ways: Tactical Operations adds a wide variety of gear and optional rules; Strategic Operations, Interstellar Operations, and Campaign Operations are more esoteric, covering a variety of mass-combat rulesets, rules for running your own mercenary units, and unusual equipment. The final core rulebook available is A Time of War: The BattleTech RPG.
BT is also supplemented by a variety of Technical Readouts, which provide gameplay and background data on 'Mechs and other units at various time periods in the game-universe history; map sets, including the new Hex Pack hard-mounted maps with tile overlays; sourcebooks; and pregenerated record sheets, as well as the aforementioned miniatures (which are not required for play).
As in earlier editions of BattleTech, introductory box sets are available. The current versions (due in October 2018) are the "Beginner Box" (contains 2 plastic 'Mechs, a map, and simplified quick-start 'Mech rules) and, immediately following, the "A Game of Armored Combat" box (8 plastic 'Mechs, mapsheets, cardboard 'Mech standees, and the full rules for 'Mechs and basic gear).