To a well-equipped party, it is simple to make it impossible for monsters to open a door.
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In Original Dungeons and Dragons, on page 14 of Men and Magic, the price list includes 12 iron spikes for one gold piece. Inflation has hit Dungeons and Dragons. In the fifth edition, on page 150 of the Player's Handbook, the price list includes 10 iron spikes for one gold piece. It is interesting to note that the fifth edition includes a price for iron spikes, but unlike almost every other piece of equipment, it does not include a description of how to use an iron spike.
Iron spikes are useful. You can jam a spike under a door and use is it as a door jamb to keep the door open. Or you can pound the iron spike through the edges of the door to keep it shut. In order for monsters to follow they have to break down the door, hopefully giving the party the few minutes they need to escape.
David Drake wrote a book titled, "Ranks of Bronze". Wikipedia describes the book as "A defeated Roman legion is sold into slavery to alien traders seeking low tech soldiers to be used in conflicts to secure trading rights on alien planets." There is an interesting passage in the book.
"Now...," said Niger, letting his eyes travel from one crewman to the other, "We're going to give you a demonstration of why you will obey every order which Gaius gives you, without argument or hesitation."
"We call it crucifixion."
"The Commander began to scream. The screaming went on for a long time."
Iron spikes have lots of nefarious uses.