Availability Rating is a code used in the Classic BattleTech game indicating how common a class of Combat Support Vehicles, 'Mech, (or other) mounted equipment, or subsystems found in the same. Its primary function is to designate how rare the systems are in a particular time period in the BattleTech universe. A similar system was used in the MechWarrior, First Edition roleplaying game. Predominantly, a weapon will have three different ratings: one for Star League era, one for the Succession Wars era, and a third for the Clan Invasion era. However, with the release of Interstellar Operations in 2016, some equipment tables started indicating a fourth code representing the Dark Age era (represented as the first of the four codes, rather than represented chronologically).
|X||Item does not exist in this era|
- Interstellar Operations, p. 33, "Availability Ratings"
- TechManual, p. 287, "Availability Codes Table"