The Horseshoe Casino Baltimore won't open until August, but the woman warrior's face on Sky Rider already glows alluringly on the second floor, offering the chance at "Silver Treasures."

The slot machine stands among a sea of recent arrivals at the Russell Street casino: Lucky Larry's Lobster Mania, A Win for All Seasons, Whales of Cash, Ultimate Sevens, Super Monopoly Money. Many remain wrapped in plastic. Hard-hatted technicians tend to the electronics of others. Some like Sky Rider are fully lit up, their wheels spinning for no one for now.

The 2,500 slot machines being installed at Horseshoe incorporate the latest technology and pop-culture themes, ranging from "The Walking Dead" to the retro 1960s-era "Batman" television show. Unlike yesterday's one-armed bandits, today's machines are more akin to video games and some even mimic arcade rides, rocking your chair like a mechanical bull.

Everything from the flashing lights and sound effects to the pace of payouts and the placement of machines on the floor are designed not only to maximize the profitability of the machines but the fun and excitement for gamblers.

Whatever the dazzling effects, the result for the casino is written into Maryland law: The house can keep up to 13 cents for every dollar bet on slots — a take it splits with the state. The rest must be paid out as winnings.

"We expect slots to be incredibly important for us," said Tom Yorke, marketing director for the Horseshoe, a $442 million project being developed by CBAC Gaming, a group led by Las Vegas-based Caesars Entertainment.

The machines started arriving at the Horseshoe Casino near M&T Bank Stadium last month. While Yorke declined to say how slots would compare as earners to about 100 table games such as roulette, blackjack and 25 tables in Caesar's trademark World Series of Poker room, the machines have been huge revenue drivers in Maryland's burgeoning casino industry.

In the past 11 months, slot machines have brought in 64 cents of every revenue dollar at the Maryland Live Casino in Anne Arundel County, where table games have been a bigger hit than some expected.

At Hollywood Casino in Perryville and Rocky Gap Casino Resort near Cumberland — the other Maryland casinos offering both slots and table games — the machines made about 85 cents of every dollar. The Casino at Ocean Downs on the Eastern Shore offers slots only.

Players buy "credits" on the machines, starting at a penny and going way up. On a penny machine, for instance, $5 buys 500 credits. On the low-priced machines, the minimum bet is rarely just one credit, and the more a player wagers, the larger the potential payout.

For the gambler, penny machines pay about 80 to 85 cents on the dollar, and dollar machines pay up to 95 cents, said Alan Woinski, president of Gaming USA, which publishes industry newsletters.

Yorke said the casino plans to install two machines that cost $500 per spin as the highest possible wager.

Asked how often he would expect such a machine to actually be played, Chad Barnhill, the Horseshoe's general manager, replied, "More than you might think."

But the Horseshoe Casino's mix of machines won't be tailored for high rollers. Barnhill said more than half of the machines would be 25 cents per credit or less, adding that the mix of values would be "very similar to what Maryland Live will have."

The two casinos — separated by about 13 miles along the Baltimore-Washington Parkway — will be Maryland's two largest for now and are expected to compete for customers.

Rob Norton, general manager of Maryland Live, which opened two years ago, said more than half of the 4,200 slot machines there play for a penny per credit.

Barnhill declined to go into detail about the arrangement of the machines on the Horseshoe Casino floor. Norton and Penny Parayo, Maryland Live's vice president of slot operations, made the analogy to the strategic merchandise placement one might see in a supermarket.

As staple items — bread, milk, eggs — are way in the back of a supermarket, meaning that customers have to walk through the store to reach them, so casinos place the most popular machines far from the entrance, Parayo said. That's where you'll find the Wheel of Fortune machine, for instance, a mainstay in casinos since 1996.

Up front in the casino you'll find the machines that pay out more frequently, with their various bells, music and visual effects, all in hopes of ginning up excitement, Parayo said.

"What you typically want as an operator is an energy, and to build that energy on a floor," Parayo said.

The newest machines use an array of sound and graphic effects, latching onto pop culture themes meant to draw both older and younger customers.

As at Maryland Live, Horseshoe Casino visitors wandering among the slots are apt to bump into characters from "The Wizard of Oz," "Willy Wonka & the Chocolate Factory," "Sex and the City," "Grease," and an array of superheroes zipping about on the Super Team game made by WMS Gaming that runs on a new, more powerful digital processor.

While conventional slot machines have one screen that shows the game symbols rolling by, machines featuring movie and TV characters usually include a second screen above that, where characters and video clips appear.

The Willy Wonka machine, made by WMS, features a chair that vibrates and moves with the action of the game, part of what the company calls Sensory Immersion 2.0. The gambler starts the game by using a touch screen to select "chair intensity," low medium or high. The company's Aladdin machine features a chair that follows the movement of a magic carpet ride.

Matt Wilson, vice president of marketing for game maker Aristocrat Americas, said the Horseshoe will have the Australian company's new machines based on two TV shows, one vintage, one current.

Batman 1966, based on the TV series that ran in the late 1960s, is pitched to the person he considers the typical slots player: a baby boomer, and likely a woman. The Walking Dead machine, based on a show in its fifth season on AMC, is meant to appeal to a younger crowd.

The Batman and Walking Dead machines represent two broad categories of slots. Batman is the sort of machine sometimes called a "dribbler," meaning it pays out more often, but in small amounts, and is designed for gamblers who want more playing time and entertainment value for their money. The Walking Dead, Wilson said, is more "volatile," paying less frequently and wired for gamblers seeking the big payoff.

Wilson and Tom Shortall, regional vice president for IGT, which makes one-third of the machines found in Maryland casinos, said their companies don't see a market shift in one direction or another between the entertainment machines and the bigger-payout machines.

Bradley Rose, vice president of game development for WMS, said his company has in the past few years moved toward the "volatile" side and now builds 70 percent of its machines that way.

"We do tons and tons of player research; we are constantly talking to players," said Rose, whose Chicago-based company is one of five whose machines are most prevalent in Maryland. He said his company's research shows that "the majority of people who come to a casino, they want to win money ... they want the chance to win big jackpots."

Rose said gamblers also get a thrill when the machine gives the appearance that they have just missed a hit — one winning symbol missing in a row, say, or a wheel that moves just past the sweet spot. Some of those methods have been outlawed as deceptive, but others are legal and they take up lots of designers' time.

"All of that is where we spend the most time," Rose said. "If they have that rush, it's almost as good as a win."

Nigel Turner, a psychologist who has studied and written extensively on slot machines as part of his work with the Centre for Addiction and Mental Health in Toronto, said slot-machine designers have two very powerful elements working in their favor: fundamental psychology concepts and weak math skills among the general public.

The basic psychology says that behavior is learned best when rewarded intermittently: Sometimes you get the reward and sometimes not, so you keep trying. The concept is exemplified by laboratory rat experiments by behavioral psychologist B.F. Skinner, who wrote about the slot machine in the 1950s as a powerful example of the same idea.

The effect is enhanced in the contemporary slot machine. While yesterday's slots player hoped to get three cherries to stop evenly on one line, today's gambler can choose machines with a dizzying array of "pay lines": straight, diagonal and zigzagging across the screen.

"The primary mechanism for holding the gambler's attention comes in the prize structure," said Turner, citing the small rewards along the way such a free spins and bonus credits that keep the player spending.

A recent study of one IGT game, Money Storm, published in January by three scholars in the Journal of Gambling Studies, found that after 50 hours of play and betting on 20 lines, only three of 10,000 players were ahead, and by less than 25 percent. The odds of winning the top prize were 1 in 215,702.

"The chances of getting that symbol all across five [columns] is very, very small ... but people like fooling themselves," Turner said. "Part of the enjoyment of the game is fooling yourself."

arthur.hirsch@baltsun.com