How does that definition work on the 30th storey of a condo building?

Fire escapes are a thing, and required in tall buildings, so it works exactly as stated.

Fire escapes are definitely not "required". You rarely ever even see them out of NYC and within NYC they've been banned since 1968.

It‘s worth noting they were banned because they weren‘t actually safer. Cramped apartment dwellers would use fire escapes as an extension of their square footage, blocking paths to safety. And they were so rarely used and tested that fire escapes becoming overloaded and detaching from the building was not uncommon.

The closet part is not actually true, it's a commonly believed myth.

There may be a few rare localities that require it, but it's not normally required.

Rather the definition requires a certain size of the room.

It’s definitely not a myth. Random examples in California:

> room can be considered a bedroom if it contains a closet, alcove, indentation or wing wall which creates an area greater than 12 inches in depth.

https://www.sanbruno.ca.gov/civicax/filebank/blobdload.aspx?...

> is capable of being used for sleeping quarters that contains a closet, or to which a closet could be added, may also be considered a bedroom.

https://www.belmont.gov/Home/ShowDocument?id=12428

A space that doesn't qualify as a bedroom is typically referred to as a "bonus room". Finished basements are one example.

In a certain US jurisdiction I have a room with a bed in it I can call a “nanny’s room” but I cannot call a bedroom on a real estate listing, as the closet for that room is through another door in a sort of hall.

In Europe though, where armoires are a thing, and I actually can’t remember living in any home that had a closet in any room with a bed, I don’t see closet being in the definition.

"The International Building Code, which is used in 49 states and Washington D.C., has no requirements for a bedroom to have a closet." https://buyersask.com/edu/code/does-a-bedroom-require-a-clos...

I keep seeing rumors that there are localities that require a closet, but no one ever actually names them.

It may be a persistent rumor in your locality as well.

According to bobvila.com, it's a difference between safety codes and assessing the property.

> Fittingly, property assessors will follow the same bedroom definition when determining the number of bedrooms in a given home—that is, it must have a door, a closet, and an egress window. It is in the interest of homeowners, sellers, and buyers to know the subtle bedroom definition differences between the safety/builder perspective and the real estate/home value perspective, and to know one’s state and local guidelines for determining what can and cannot be considered a bedroom.

https://www.bobvila.com/articles/406-what-makes-a-room-a-bed...