The former manager of the Progress Club likened the Rockville operation to a gambling casino yesterday during testimony in a trial that has become as social as the club itself.

The testimony by Michael Richards was a key element of the prosecution's case against Progress Club Inc., the corporation that runs the club and that is accused of operating a place for gambling in violation of Maryland law. The state finished presenting its case yesterday, and the defense began calling its witnesses.

One defense witness, Hans Gross, seeking to show that gambling is not that uncommon, said he had played gin rummy for money at various clubs, including the Army-Navy Club and the officers' clubs at Fort Belvoir and Fort Myer in Virginia. However, in interviews, spokesmen for those clubs said such gambling is strictly against the rules.

But much of the testimony took a back seat to merrymaking in the Montgomery County Circuit Court. At least 80 club members and their wives and families jammed Judge William Miller's courtroom, spilling out into the vestibule. They frequently disagreed aloud with testimony and waved and smiled at friends.

Miller, the jurors, the prosecutor, defense attorneys and courtroom audience laughed often during the six-hour session yesterday, while either the prosecutor or defense attorneys seemed to make an objection every 15 minutes.

After raising one such objection, then appearing to change his mind, the club's lead defense attorney, Barry Helfand, told the judge: "Just let the chips fall where they may."

Assistant State's Attorney Matt Campbell had physical evidence -- poker chips, cartons of playing cards, financial records and membership and card game logs -- hauled into the courtroom on a dolly. Cartons of such evidence, along with an estimated $21,000 from club coffers and $8,000 from members, were seized by Rockville police June 5 in a late-night raid that culminated a 5 1/2-month undercover investigation of the club's five-night-a-week poker and gin rummy games.

The corporation that runs the 72-year-old club has pleaded innocent to six counts of maintaining a place to gamble. The club's lawyers argue that poker and gin rummy are games of skill, not chance, and therefore are not illegal under Maryland law. If convicted, the club faces maximum fines of $6,000 -- $1,000 for each count.

Richards, who managed the club for 7 1/2 years and is now its chef, testified that although the club's 500 members ate, drank, worked out and socialized there, the main activity at the club was card playing. Members paid $3 for each deck of cards, $12 to play poker and $9 to play gin rummy, he said.

Richards was arrested in the raid and charged with 12 counts of running a gaming place, but he was granted immunity from prosecution in exchange for his testimony.

Richards, who kept detailed records of card games, said 9,822 men played cards for money at the club from last January through last May.

Prosecutor Campbell also called two club members, who testified that they played cards for money at the club routinely.

Helfand and Goldstein urged Miller to dismiss the case, arguing that the state antigambling law had been replaced by a Montgomery County ordinance prohibiting games of chance but allowing games of skill. Miller denied their motion, but encouraged them to try again at the conclusion of the trial.

Defense witness Gross, a 71-year-old toy distributor from Savage who is a member of the club, said that he had played gin rummy for 55 years and that it was purely a game of skill.