The classic joke, still appreciated by parents about to embark on a vacation with their youngsters, divides travel into two (and only two) categories: "first class" and "with children."

There's truth to this, as most parents will acknowledge, but at the same time a great many of them not only take the kids along on most trips but wouldn't dream -- at least seriously, anyway -- of leaving home without them.

Recognizing this, most of the big hotel and motel chains in the United States have put together special family packages. They are aimed at families on the road who may be driving to a sightseeing attraction, such as a national park, or on their way to visit relatives. Many good packages are available even in the country's major tourist cities, such as Washington, New York and Boston.

Some of the plans woo the youngsters with special recreational programs. The Omni Park Central Hotel in New York, for example, has introduced a "concierge for kids," a staff member whose primary responsibility is to advise families on kid-oriented attractions in the Big Apple this summer.

But more important, most packages also cater to one of Mom's and Dad's major concerns: the price of a night's lodging. In many cases, families of three or four can share a room with two full-sized beds for no more than it would cost the parents alone. And at least one nationwide chain, Ramada Inns, treats children under the age of 12 to breakfast and dinner free (from a child's menu) if they dine with their parents -- provided, of course, that they are staying at a Ramada.

The result is that families can plan getaways that include one or more nights in a hotel or motel and still manage to do so on a reasonably modest budget. The best time for bargains is during the summer -- when most families tend to travel because school is out -- and on weekends throughout the rest of the year. Bookings for business travel slacken in summer and on weekends, and hotels and motels eagerly look to families to fill empty rooms, especially in the big cities.

Some parents will argue that no vacation can be all that much fun when the youngsters are tucked into the adjacent bed, allowing Mom and Dad only minimal privacy. Savvy hotels have considered the situation, however, and have come up with a solution that, belying the old joke, actually adds a touch of class to travel with children.

For example, on weekends the Hyatt hotels offer a second adjoining room for the offspring at one-third off the regular rate. And this summer at the Omni Park Central (800-THE-OMNI), children can occupy a second adjoining room for free when their parents book a room at the Omni Central's regular $149 a night rate.

Families contemplating a trip that involves hotel and motel stays have a better chance of saving money if they plan ahead, making advance reservations rather than picking a place to stay as evening approaches. At the very least, they should be aware that the major chains have differing policies regarding rates for children.

The most common practice in the hotel/motel industry is to permit children under 12 to stay free in their parents' room, although this is not the case everywhere -- especially at popular resorts. Usually the limit is two or sometimes three children per room. Some hotel chains are more generous, putting the age limit at 16 (Quality Inns) or 17 (Ramada). Days Inns of America currently offers a "Simple Super Saver" special that allows four people in a room no matter what their age.

Some of the best rates are available only to travelers who book in advance. Days Inns is advertising attractive rates for families this summer, ranging from $19 to $39 a night (depending on location), but accommodations must be reserved 29 days in advance. Other hotels and motels limit the number of rooms available at discount rates, which means they may be filled if you show up at the last minute.

Most hotel and motel chains have toll-free reservation numbers. The reservation clerk can describe any family packages currently available. Most packages change with the season, and not every property in a chain may participate in these special offers. The reservations clerk can book you in a hotel or motel that does.

Beyond free beds for the kids, perhaps the next most important amenity that a hotel can offer a traveling family is a swimming pool. A dip after a day on the road can wash away any number of irritations, quieting rambunctious youngsters while reviving their parents. Several hotel/motel companies -- among them Holiday Inns and Best Western -- make it corporate policy to provide a swimming pool at all but a few properties. With a reservation, you can be assured that a pool is waiting for you.

If one or more hotel/motel chains appeal to you -- because of the room rates or the amenities -- obtain a copy of the chain's directory before you leave home. The booklets provide room prices for each property, a list of such amenities as a swimming pool and often a street map to guide you to your night's lodging. The reservation clerk can tell you how to get a copy of the directory.

One final reminder: Always be sure to ask if a family plan is available, whether you phone ahead or just drop in. Many desk clerks will quote a standard rate unless you ask for a specific discounted package.

Among the family programs available this summer:

Ramada Inns: "Ramada built its image on families," says spokeswoman Jeanne E. Miller, and they remain "an important market." The chain, which has 500 properties throughout the country, offers a Family Bonus Plan at about 300 of them. And parents planning a trip with the children can send off for a free "Parent's Survival Guide."

The current plan, which is available daily through December, allows a family of four (with children age 17 and younger) to stay in a room at the single rate. Children under 12 can eat free at breakfast and dinner when ordering from the Ramada Kids Eat Free Menu. "They won't get lobster," says Miller, but they will find hamburgers, hot dogs and other dishes popular with youngsters.

In addition, each family receives a coupon for $5 off the next night's stay at a Ramada and a chance to win next February's drawing for a family vacation in Australia.

The "Parent's Survival Kit" is a packet of goodies that includes a six-page game book for children; a small coloring book with crayons; a 191-page paperback book titled "Coping With Kids and Vacation," by psychologist Linda Albert and writer Elaine Fantle Shimberg; and a $5 coupon off the first night's stay at a Ramada on the Family Bonus Plan. The kit can be obtained by writing Ramada Hotel Group, "Parent's Survival Kit," Marketing Department, P.O. Box 29004 BG, Phoenix, Ariz. 85038.

For Ramada information and reservations: (800) 272-6232.

Days Inns: Days Inns "Simple Super Saver" offer is not specifically aimed at families, but they certainly can take advantage of it. From now into the fall, four people can share a room for a rate ranging from $19 to $39 a night (depending on the location).

"It's patterned after airline discount programs," says spokeswoman Carol Bivins, and like the airline programs there are restrictions and a cancellation penalty. You must book 29 days in advance and prepay the first night's stay. You get a refund only if you cancel up to 15 days before your scheduled arrival. The chain has more than 500 properties in 45 states.

For information: (800) 325-2525.

Best Western: Best Western is an association of 1,900 individually owned motels throughout the country. About half of them permit children under 12 to stay free in their parents' room and about one-third allow children 18 and younger to stay free. At least "99 percent of them" have swimming pools, according to spokeswoman Sue Schweller.

Best Western distributes a "Road Atlas and Travel Guide," available at any Best Western motel, that describes each of the 1,900 locations. The symbol of a smiling face indicates those where children under 12 can stay free. To determine which ones accept older children free, you must contact the central reservation number. For special packages, particularly at resort areas such as Disney World in Orlando and Niagara Falls, ask for the "Packages Department."

For information: (800) 528-1234.

Quality Inns: All but a few of Quality Inns' 750 locations in the United States invite children 16 and younger to stay free in their parents' room. Some properties allow older children.

Quality International, the parent company, includes budget-priced Comfort Inns, mid-priced Quality Inns and deluxe Clarion hotels and resorts.

For information: (800) 228-5151.

Hyatt Hotels: Once largely known as a commercial hotel chain, the 85 Hyatt hotels in the United States are now making a bid for the family market, says spokeswoman Carrie Recket. One trend the company has spotted, and is capitalizing on, is that more and more convention-goers are bringing along their families.

With room rates in the higher brackets, Hyatt hopes to appeal to families with first-class tastes who nevertheless are looking for a bargain.

On weekends through Sept. 15, parents can book a room for themselves at a discounted weekend rate and get an adjoining room for children at one-third less. Throughout the week, children under 12, when dining with their parents, can order any item from the restaurant menu at half price.

Meanwhile, individual hotels feature special family amenities. The Hyatt Regency Washington of Capitol Hill, for example, has opened a Children's Suite this summer. It is a supervised day-care center for children ages 4 to 12. It is open from 8 a.m. to midnight, and the fee is $15 for four hours. At the Hyatt Regency Scottsdale in Arizona, parents get mints on their pillow at night, but for the youngsters the treat is milk and cookies.

For reservations: (800) 228-9000.

Hilton Hotels: "Summer of $59" is what Hilton has dubbed its summer program. Good through Sept. 7, the package offers a room at 216 of Hilton's 271 U.S. hotels for $59 a night, provided travelers stay at least one Saturday night. Children (no age limit) stay free in their parents' room, and everyone gets a complimentary continental breakfast. The room must be booked at least two days in advance.

At some resort areas, however, summer is a bit more expensive, although the rest of the package is the same. The rate at the deluxe Fontainebleau Hilton Resort and Spa in Miami Beach, for example, is $89 a night for a family.

For information: (800) 445-8667.

Holiday Inns: Though individually owned, 1,000 of the 1,400 Holiday Inns in the United States have put together a "Summer Great Rates" program, good through Sept. 6. Depending on location, participating motels are offering rooms at $29, $39 or $49 a night. Two or three children 12 and under stay free in their parents' room.

After Sept. 6, Holiday Inns plans a "Great Rates" program for weekends (Friday, Saturday and Sunday), with 20 to 50 percent off midweek rates.

Rooms for either program must be booked at least seven days in advance, and the first night's charge must be guaranteed with a credit card or by sending a deposit.

For information: (800) HOLIDAY.

Inter-Continental: Another upscale chain, Inter-Continental has reduced room rates this summer at 10 of its U.S. hotels in a promotion called "Vacation America." Through Sept. 7, a family of three or four can share a room at a rate of $59, $99 or $125 a night, depending on location. Individual hotels may require a two- or three-day stay, and advance reservations are necessary.

The rate at Inter-Continentals in Houston, Miami, New Orleans and San Antonio is $59 a night. (The standard rate at the Inter-Continental New Orleans is $155 a night.) At Maui and San Diego, $99. In New York, San Francisco, at the Willard in Washington and Hilton Head in South Carolina, $125. Suites also are available at much reduced prices.

For information: (800) 33-AGAIN.

Howard Johnson: In all but a few of the 450 Howard Johnson hotels and motels in the United States children under 18 can stay free in their parents' room. Individual hotels may offer discounts for children at Howard Johnson restaurants.

Howard Johnson is a franchise operation, so locations often differ in their policies. For example, a number of Florida Howard Johnsons have banded together to offer family rates at $25, $35 or $45 a night, depending on location. Reservations must be made at least three days in advance. For reservations: (800) FLORIDA. A similar promotion is planned for California in the fall.

For information regarding other Howard Johnson locations: (800) 654-2000.

Marriott Hotels and Resorts: Marriott calls its popular promotion a "Two for Breakfast Weekend," a romantic thought, but this chain of big, modern hotels also invites you to bring along up to three children (no age limit).

Depending on location, rates range from $59 to $89 a night for stays on Friday or Saturday. The price includes "a hearty breakfast for two." Breakfast for youngsters 12 and under is $1.95 each. Advance reservations are advised. All but a few of Marriott's 169 properties are participating.

For information: (800) USA-WKND.