LAS VEGAS — A lucky swap and some eager building propelled a 19-year-old Norwegian student to the top of board game fame and sent three would-be tycoons to the poor house at the Monopoly World Championship in Las Vegas.

Bjorn Halvard Knappskog, who graduated this year from the Oslo Private Gymnasium school, captured the title on Thursday when the battleship token of 25-year-old Geoff Christopher of New Zealand landed consecutively on Pacific Avenue and North Carolina Avenue, and he couldn’t afford the combined $1,600 rent.

“(I’m) the most surprised you could ever be,” Knappskog said. “I think this was a really good final. It was the best game I played in the whole tournament.”

Knappskog won $20,580 in real money for the title — the total amount in the bank of a standard Monopoly game. The other finalists won nothing beyond the trip that brought each of the 41 competitors to the Caesars Palace hotel-casino on the Las Vegas Strip to represent their home countries as national champions.

After taking out 24-year-old Russian Oleg Korostelev, Knappskog bankrupted American champion Rick Marinaccio, a 26-year-old corporate lawyer from Buffalo, N.Y., who was trying to become the first U.S. player to win the board game championship since 1974.

Knappskog was the only player without a monopoly after trades gave Marinaccio the magenta property group, Christopher the oranges and Korostelev the more expensive greens.

But the game turned when Korostelev swapped Knappskog a cheaper light blue property to gain the red property group, giving Knappskog an inexpensive monopoly with cash to develop. The moved surprised Knappskog and the other players because Korostelev couldn’t afford to build on the property group and didn’t negotiate for cash.

“I thought I was in such a great position,” Marinaccio said. “I didn’t see that coming and I don’t think New Zealand saw that either.”

Knappskog mortgaged his other properties and loaded up on hotels for Oriental, Vermont and Connecticut Avenues, seeing his opponents’ tokens within range of the spaces on the board.

The move was risky because his iron token faced a gauntlet side of developed magenta and orange properties, and Knappskog said he may have lost if his opponents dodged his hotels.

“Either they come to me and I get enough money to survive, or I go out,” he said.

He finished with $6,888 in cash and assets in the game.

The world tournament, held periodically and last staged in Tokyo in 2004, began Wednesday at Caesars Palace with players from 41 different countries. Games were played in English, with interpreters on hand to help players who spoke different languages negotiate trades with one another.