AbdulAlhazred
Legend
then why did the rules measure movement and spell ranges in inches? It's quite clear there was an underlying assumption, players would be using miniatures.
I agree. Although even 1e is a bit vague on exactly how space and movement work once you get 'engaged' in melee, the game very definitely assumes a sort of 'battle space' where everything has a location and you can make measurements (and nominally it has a scale). This is all directly descended from the original D&D rules, which resolved combat using Chainmail, with the exception that indoor areas were mapped 1" = 10' instead of 10 yards. They even have a scaling of AoEs and ranges so that everything takes up the same inches underground that it does above (in other words, the game is really played in inches, not yards or feet).
Early D&D play ALWAYS had minis. In fact there was a standing rule in our game club (which had a few 100 members) that you couldn't run a character unless you had an accurate figure for it. If the only dwarf you had was wielding a mace, guess what weapon your PC got to use! Maybe that was a bit extreme, but everyone seemed to think that was how it was played, and it was very 'wargame mode'.
Admittedly, that had pretty well worn off by the mid-80's. OA maintained the conventions for example, but the play didn't really emphasize large complex fights, it was more 'stab in the dark' and 'get executed by the emperor for being offensive at the poetry contest' or something.