TThe other evening my 12-year-old daughter challenged me to a game of jacks. She had been playing jacks for about six months and had never asked me to play with her--which was all right with me. I burned out as a jacks player about 30 years ago, although I was unbeatable in my prime. Even Helen Mills--a prissy, lynx-eyed little girl whose sweater cuffs never hung down over her knuckles and who always carefully removed her l7-jewel Bulova watch before she settled down on the floor--could never get beyond "Cherries in the Basket" before I was sailing ahead with "Flying Dutchman." Jacks playing was one of my small triumphs back in the days when large triumphs were always in another room.

"I warn you," I said, easing down into the classic, side-saddle position on the kitchen floor, "I'm pretty good."

My daughter, who had heard me say the same thing at the roller skating rink the month before, smiled tolerantly. "Sure, mom," she said. "I'll go first."

"Okay," I agreed, as she prepared to "pinkie" for the honor of throwing first. Large spirits don't quibble.

She flipped the jacks from her palms onto the backs of both hands. All but two hit the floor.

"My turn," I said cheerfully, reaching for the jacks.

"No it's not," she said emphatically. "I get to 'pinkie' over."

"Says who?" I demanded. "If you don't catch them all, then it's the other person's turn."

We argued over this. The rules, said my daughter, had changed. The rules, I countered, were inflexible. Yes, no, the generation-jacks gap widened with each retort, and before the game foundered on technicalities I decided to concede. "Okay, have it your way, but I think it's ridiculous."

She threw her first hand. I leaned over to study the configuration of jacks on the floor.

"Trash," announced my daughter.

"Trash! What are you talking about?"

"I don't like this hand. I'm trashing it. You're allowed."

It turned out, in this revised and slovenly game of modern jacks as played by today's 12- year-old girls, that almost everything is allowed. "Haystacks!" she proclaimed at one point, picking up two jacks on top of each other and placing them down somewhere else more convenient. "Mother's Helper," she said when she caught the ball against her chest. "Kissies," "Pop-jack," -- there were so many ways to keep from forfeiting one's hand that the old days of "if anything trembles, you're out" were obviously gone for good.

"When I was playing jacks," I said self-righteously, "we didn't have 'Haystacks,' 'Trash' and 'Mother's Helper.' It's just like cheating, only you make up other names for it."

"This is the 20th century, moth-urr," answered my daughter. But finally she made a mistake that the 20th century had not invented a "cover" for and the jacks were mine to toss.

"I'm going to play the old, difficult way," I announced. My daughter sighed. Her mother was a masochist who didn't know how to have a normal good time.

I "pinkied" without dropping a single jack. (I had not lost my touch.) "Twosies," "threesies"--swiping my way through the first round of 10, I remembered why I had lost interest in the game. It was a little boring. But as I relentlessly mopped up the linoleum with my wonderfulness, my daughter lapsed into a deep, respectful silence.

Then the telephone rang. It was for her.

"I'm playing jacks with my mother," she said. A short silence ensued. "No," she sighed, "she's ex-cellent." Her magnaminity made me feel small. Having "trashed" her prospects, I wondered whether I ought to hold my fire a little and fake a mistake to give the jacks back to her. But I was too hot to retire. She hung up the phone and came back to watch me play.

"Guess what?" she finally interrupted softly.

"What?" I asked, as I "pinkied" into the fourth game. Was there no stopping me?

"On the math test Miss Gay gave last Friday, I was the only one in the class who got l00 percent."

"Really?" I exclaimed. My heart twitched at the timing of this announcement. "The only one?"

"Uh, huh," she said, "and if I had missed even one answer, my score would have gone down to 80."

"That's really excellent," I said, purposely misthrowing the ball so that it came down on a jack.

"Ah," I exclaimed with mock chagrin. "I missed. It's your turn now."

"No, it isn't," replied my daughter, her face solemn with integrity. "That's called 'Pop- hand.' You get to take it over."

Something inside trembled. But this was the 20th century. I was forced to play on.