Q: We haven’t been to Las Vegas in a couple of years, and want to book a visit for next month. We’ve been warned to stay at a hotel that does not charge resort fees. What are resort fees?

Jay S., Providence RI

A: It’s a hidden extra charge, similar to what airlines do to lure customers. For example, when you book a round-trip flight advertised for $99, the real amount you pay may be $120 or more, because of fuel fees, taxes and other add-ons.

Similarly, some Las Vegas hotels will hand you a bill when you check out that charges an extra $20 a night resort fee. It means that advertised bargain of $79 a night will actually cost you $99 or more.

The official reason: the charge is for the daily newspaper, nightly turn-down service, use of the gym, pool, two bottles of water and other unspecified facilities. And, yes, you’re required to pay even if you haven’t used any of those so-called services.

Of course, resort fees aren’t only being charged in Las Vegas. You’ll find them at hotels in other popular vacation areas. If you don’t want to pay resort fees, be sure you book a hotel that doesn’t pile them on.