"If you come with nothing in mind, forget it. You could go crazy in here."

Loretta Crawford looked grim as she guided her cart through Toys-R-Us. The other night she and her sister-in- law braved the emporium at Baileys Cross Roads on behalf of their four kids and a slew of nieces and nephews. "After we've finished, we'll probably stop off at a bar," Michelle Crawford said.

Necks craning, eyes upturned, they cowered in a canyon of toys. Perched in high stacks and looking ever-ready to lunge were the Masters of the Universe, He-Man ("Most Powerful") and Skeletor ("Lord of Destruction"); Luke Skywalker and Darth Vader of the Star Wars Micro Collection; Pretty Cut & Grow, a doll sporting replaceable hair; scented Strawberry Shortcake and her new, redolent friends; plush Hershey Bear, chocolate-perfumed; bug- eyed E.T. holding a tiny Speak & Spell; Dukes of Hazard Mini Choppers; G.I. Joe ("A Real American Hero") and his Official Key Rings, Dog Tags and Bullet Charms; plus a swarm of Smurfs, fuzzy or rubbery, with records, card games, puzzles, color-by-number sets and other Smurf essentials.

These are some of the latest in this year's crop of toys. But if it seems a head-spinning heap, the theme is still pretty simple.

"Toys have changed, but there's really nothing new under the sun," said Ian McDermott, senior buyer for F.A.O. Schwarz, which competes with Toys-R-Us in the $8-billion market. "I would say most of them are just the basics, but wrapped up in new guises."

Said Norman Ricken of Toys-R-Us: "There's always been one thing that makes a good toy: its play value -- the amount of interest it holds for the child, its staying power."

Stalking the elusive play value, such toyfolk as Mattel, Kenner and Gabriel pay legions of researchers and engineers. Play-testing, the genial science, enlists thousands of kids to tinker with toys. One company, Fisher-Price (maker of such marvels as Magic Show and Power Tow Truck), runs its own pre-school in upstate New York.

"It's on our premises in East Aurora," said Fisher-Price's Carol Blackly. "It looks like a pretty typical nursery-school room, with the toys -- both ours and the competition's -- placed along the walls in what look like little cubicles. There's a one-way mirror, behind which designers and engineers can watch the children at play. We tell the children that they're helping us make new toys, but I'm sure they don't think of themselves as toy-testers."

Ian McDermott, who's been at Schwarz for 20 years, remembers when someone would have a flash of inspiration, with his toy coming to market with hardly a backward glance. Nowadays it happens methodically. "We get hundreds of unsolicited ideas every month," he said. "If I think they're worthwhile, I like to channel them to the right sources. But it's very difficult to enter the portals of a firm like Fisher-Price."

Things still can be dicey. Mattel's Masters of the Universe, a new line of "male-action" toys, didn't much charm McDermott when the company brought it out last February. Now, without the help of F.A.O. Schwarz, it's one of Mattel's hottest sellers.

"It's a line of dolls, 51/2 inches tall -- very muscular- looking characters from a fantasy age," said Mattel's Peggy Hummes. "There's He-Man, who's blond, wears a breastplate and carries a battle ax, and his nemesis, Skeletor, who has a skeleton face and represents evil. Two other bad guys are Beast Man, who looks beastly, and Mer-Man, who's kind of scaly-looking. He-Man's allies are Zodac, Stratos and Teela, the mystical warrior goddess. There are also accessories like a Battle Ram, a four-wheeled vehicle with a battering ram, and a Battle Cat, which is a green tiger with orange stripes. The two sides fight for the Castle Grayskull, which is entered through a Jaw Bridge. Whoever controls the castle is Master of the Universe."

The all-plastic set comes with a story book -- "Now it was Mer-Man's turn to be knocked senseless" -- and can be bought piece by piece for about $80.

Kenner's popular doll Strawberry Shortcake -- a spinoff from both a greeting card and a TV show -- comes in four sizes this year with a scented menagerie: Custard the kitten, Pupcake the dog, Rhubarb the monkey et al.

"I tried to buy one last year," Loretta Crawford said. "I remember one morning, people actually stampeded through Zayres to get at them. They were gone in a matter of seconds." Michelle stopped to gaze at the Strawberry Shortcake shelf. She shook her head. "All I ever played with was one miserable doll. It was just me and Tiny Tears."

Said Kenner's Dave DeMala, "With any doll that becomes a hit, there's a certain amount of magic. Just like there's a lot of handsome men around, but there's only one Robert Redford."

Sometimes the magic can take a strange twist. "Last month, we got a letter from a little girl in Oregon. She wrote that she was holding her Baby Alive doll hostage, and that unless she received a new toy, nobody would ever see it again. Of course, we'd never bow to that kind of demand. It was pretty spooky."

Ian McDermott, though, offered a different interpretation. "How often do you see young children traveling with their favorite toy? A toy that looks as though it's been dragged around the world. Every child, in a sense, holds his toys hostage.""