This command allows you to attempt to block people from taking a certain exit from your current location. Blocking is automatic, and it can be tiring. Every time you resist someone from blocking, it will wear you down a bit. The chance for you to block someone is a factor of a number of things, including how worn out you are (the percentage of your maximum endurance points that you currently possess determines the bonus or penalty in your chance to block someone). Each blocking attempt costs 10 ep, and if you do not have enough endurance to block someone, they will easily get by you.
block allow <name>
block allow remove <name>
You can set up a list of people you will not block with the block allow option, and you can check this by typing: block check. You cannot have more than 10 people on this list. Keeping track of more than that would be too much to think about when trying to block someone else from leaving.