Here’s another AD&D rule that I came across in the section on doors that I don’t ever remember using:
Regardless of how a door opens, it is usual that its weight and condition require that force be used to swiftly operate it. This is represented by the roll of d6 for each person involved in pushing, pulling, lifting, sliding, or whatever. A roll of 1 or 2 typically indicates success, anything above indicates the door still remains unopened. (Cf. PLAYERS HANDBOOK, Character Abilities, Strength.) Very heavy doors might reduce chances by half. Locked doors might only open if two or even three simultaneous 1’s are rolled. (DMG, page 97)
Note the bolded sentence. I’m positive that I would not have allowed a locked door to opened. Broken down, but not opened. The wording of this and the description of Open Doors under Strength in the PHB seems to refer to opening (“operating”) doors, though I know some people (and maybe the rules of some editions) indicate that the result may be a broken open door.
I’m sure I read this many times back in the day, as I read the book cover to cover several times and often just opened up to a random page and started reading. But I don’t specifically remember it.
Did/does anyone play that rolling a couple 1s on Open Doors checks opens a locked door?