Recently I had a chance to look at a copy of the Mechwarrior RPG’s 1st edition, and realised that in some respects it was the last gasp of a very old-school approach to RPGs. You see, just as Dungeons & Dragons in its original edition had that longstanding connection to Chainmail – perhaps never actually used in the context of an RPG session, but there if you wanted to resolve a mass battle in your D&D campaign world – and just as 1st Edition Chivalry & Sorcery considered shiftng between roleplaying and wargaming to be sufficiently central to play that it included a full wargaming system in its core rulebook, Mechwarrior is an RPG joined at the hip with a wargame – in this case Battletech.
So far, so obvious; Mechwarrior never pretends to be anything other than the Battletech RPG. So far as I can make out, this extends to an assumption that ‘mech combat will be resolved via Battletech gaming; whilst a combat system for person-to-person combat and other non-mecha combat forms is provided, the actual ‘mech-based material here consists of additions to the Battletech rules, rather than a restatement of them or a reformatting of them for theatre-of-the-mind play.