In classic BattleTech gameplay, Record Sheets are a key component besides the game board, playing pieces, and dice. (Alpha Strike rules use a simplified data sheet, and the MechWarrior: Dark Age game uses the Clix system of dials in a given playing piece's base to depict its current status.)
Record Sheets are used by players to record the configuration and battlefield condition of an individual unit (playing piece), be it a BattleMech or another vehicle, infantry unit, or fixed gun emplacement. There are no record sheets for regular buildings, minefields, or other terrain features although depending on the scenario and being played and the exact rules used, some sort of stats may have to be kept for these as well.
For standard gameplay, a unit's record sheet needs to include (at the bare minimum):
- some core game data about the unit, such as type, designation, mass, movement points, etc.;
- the individual sections/hit locations with their armor and internal structure values (where applicable); these usually take the form of boxes that are ticked off as damage is incurred; and
- the critical slots representing individual sub-systems, to determine the exact configuration of the unit as well as to track damage to internal components (if applicable).
FASA and later FanPro and Catalyst Game Labs have produced and sold official record sheets, a product line going hand-in-hand with the popular Technical Readouts product line. "Official" blank record sheets for all unit types are also provided, and have been an important factor in the popular construction rules aspect of the game. Several software projects including the official Heavy Metal Pro suite and various fan projects also cater to this, and can produce record sheets.
Note that it is not technically required to use "official" record sheets for playing, as long as the exact unit configuration and condition is properly recorded somehow.