Splitting the market (Forked from: What D&D is to me, in terms of editions.)

[S'mon]

I never realised running 1e AD&D with Unearthed Arcana that the 1e MM was written for OD&D/Holmes, but I always wondered why the monsters seemed so weak. Makes me want to run a campaign with the 1e MM used alongside Moldvay or Mentzer Classic, or maybe Labyrinth Lord.