While I was recently looking at the wilderness encounter tables on page X57 and X58 I was thinking about the probabilities of city encounters. Below is a table that lists the probability of having a specific encounter given in the random encounter tables as well as how many times each encounter would happen in a year. It assumes one random encounter check per day using the dice rolls given on page X57 and X58:
A few observations off the top of my head:
1. The typical B/X city is a place of commerce - the highest probability is with a Trader followed by Bandits.
2. Two encounters with Ghouls in a year?!? What kind of place is this? How do the normal humans survive?
3. You will encounter a Dwarf, Elf or Halfling as often as a Goblin, Orc or Ogre. I find the low probability of encounters demi-humans interesting. Also, the chance of encountering a chaotic humanoid is higher than I thought. Not quite Mos Eisley but more monsters wandering around the city than I thought.