MY FAVORITE William Hamilton cartoon shows an older man telling his young female dinner companion, "Money is life's report card." The drawing that conveys this pontification is elegant, as Hamilton's always are --his signature may be the classiest American autograph since John Hancock's--but the caption can exist quite well on its own. (Indeed, it is something of an apothegm for the '80s.) Unlike the drawings of his New Yorker colleague, George Booth, Hamilton's exhibit little body English: generally the composition is simply two or four talking busts. Small wonder, then, that this most verbal of cartoonists has switched nibs and penned a novel.

The Love of Rich Women depends on a stock American plot: poor lad with ethnic name courts blue-blooded heiress. Hamilton does impart a few variations to the theme. The ethnic, Dan Novitski, has impregnated the heiress, Rowena McDonald. And she has been less than forthright about her lineage and wealth. As the lovers drive Dan's van from Boulder, Colorado, to Connecticut, where they will break the news to Rowena's family, she tries to prepare him for the splendor. But nothing can adequately presage the mansion in which the McDonalds live. "It looks like the capital of something," Dan quips.

Adhering to a well-traveled path is eminently forgivable in the first novelist, particularly one who, like Hamilton, is every bit as interested in style as in substance. As fans of his cartoons know, Hamilton is a master of condensed witticisms, and of these the book has its share. Rowena first took a shine to Dan at a fraternity party. "He wasn't particularly drunk, which she thought was original. Rowena had been brought up to seek the best." When pompous paterfamilias John Russell McDonald daydreams of the proper spouse for his daughter, he comes up with Lord Cove's son. "He was a fine specimen; maybe a little too pink and hairless, something like an eraser, at this stage of his development, but Englishmen age beautifully." When Rowena, with the announcement of her pregnancy, captures her workaholic father's total attention for the first time in her life, she finds that attention "a little scary . . . like being looked at by an atom bomb."

At times, however, Hamilton's style runs into trouble. Disregarding his instincts for pithiness, he tends to strain for humor in overwrought images: one character's laughter "seemed to be bumping downstairs, the trunk of a fan dancer jumping the bill late at night in a tank- town hotel." Quite a laugh, quite a modifier. And this sentence loses its way and mixes its metaphors with giddy celerity. "The future disappeared, replaced by a swiftly backtracking present that sucked memory and fantasy into its stains and tears as it rushed toward old pain and forgotten nightmares." Is this backtracking present a train, a Hoover, or a tear-stained handkerchief?

But aside from these occasional tumults in the prose --and an extremely farfetched coincidence on which the plot jerkily pivots--The Love of Rich Women is a smoothly entertaining performance. The book displays such intimate knowledge of the McDonalds' regal life style that Hamilton might well have entitled it "The Ultra-Rich Handbook." The mere choice of the University of Colorado as Rowena's college is a perfect bit of business. With its superb scenery, its lordly position above Denver, its ski bums and aging flower children, Boulder is the ideal habitat for Rowena, who wants to shrug off her ostentatious background without forfeiting much in the way of chic. And there is the magnificently telling requirement that John McDonald's chauffeurs have the same shoe-size as he. Why? One of their duties is to break in his shoes.

Dame Rebecca West has said she wrote her novel about rich people, The Thinking Reed, "to find out why they seemed to me as dangerous as wild boars and pythons." Hamilton also takes up such an inquiry, in the book's darker second half. His answer seems to be that, although all of us are prone to manipulate our peers and lovers, the very rich--having such a high probability of success--find the temptation all but impossible to resist. Even rebellious Rowena ultimately wants to remold Dan into something like her father's image. As an outsider Dan can put the McDonalds' wealth in perspective: He considers it "a green hell of cash so dense, you couldn't even see the sun." This resonance in Hamilton's first novel comes as a welcome surprise. He has refused to settle for merely translating his arch cartoons into another medium. The Love of Rich Women has an inner-sanctum mordancy all its own.