I was just testing out the feature alluded to in the "Playing Games Wrong" thread by restarting my original dungeon with all the levels and items my character gained on his first run, and I made a couple chance discoveries. Both relate to hit/miss outcomes, so Trev may be particularly interested.
First, apparently the manual wasn't lying about level affecting THAC. I went through the entirety of floors 1, 2, and 3 with 100% hit accuracy!
![Very Happy :D](./images/smilies/icon_biggrin.gif)
Second, at one point I was fighting a gargoyle at the outside corner of a room. The wall was only taking up the left 1/4 of the screen, but apparently it was blocking our attacks, because we both were consistently missing. I moved away from the room and the problem was immediately solved. So, something to look out for there.