Doorways are such an essential part of party fighting, but they also seem to be an essential part of dungeon design. I feel like I understand a lot more about wandering monsters and surprise when I looked closer at bothered to read the section on doors.
I was reading a D&D for kids game. Basically, failed attempts at opening stuck doors meant a chance of wandering monsters. I use this, and also use it to help determine surprise. A failed attempt to open a door is basically forfeiting surprise chances, it's not really about the party spending all day trying to open the door. How long will the occupants remain alert for? I don't know. 0e has doors opening only on a 1-2, and they are reluctant to stay open. Moldvay has the same thing.
This creates an unusual low-probability ideal scenario: to get the drop on the occupants, you have to hear them (1-2 on d6 with a thief or demihuman) and get the door on the first try (another 1-2 on d6 with average strength—high strength is a great leverage point here!)
When one considers that entering a new room and closing the door may frustrate pursuit from wandering monsters, it makes sense that there be some small tactical difficulty in exploiting doors and doorways. They seem set against the party!
Spiking a door fails on a 5-6 on a d6, too!
What do you think of this? Unfair? Common sense to you, already?