At the time, people traveled in stagecoaches and covered wagons, often through dangerous areas. Next to the driver in these vehicles sat a person holding a shotgun. That person’s job was to guard against robbers or angry Native Americans.

These days, riding shotgun still means you are sitting next to a driver, but without a shotgun.

In a vehicle, the seat next to the driver is roomy. Sitting there, you can see the world around you better than people in the back seat. It is easier to talk to the driver. And you have access to the music player and climate controls.

So, to guarantee that you get this good seat before a car ride, you can call shotgun. In other words, you are claiming, or calling dibs on, the seat next to the driver.

This is a fairly common expression in American English. But it is very casual and somewhat humorous. So, we usually say it only to our very good friends.

I would not, for example, call shotgun on a drive with the head of my office or my mother’s friend, who is probably 80 years old. That would be a sign of bad behavior. The older adult should get to choose where they sit.

I would even think twice before calling shotgun with a new group of friends. It could sound childish. Instead I might say, “Would you mind if I sit up front?”