Scavenger by David Morrell

Scavenger - Frank Balenger and Amanda Evert, who he rescued in Creepers, are working to put their experiences in the The Paragon Hotel behind them.  They are invited to a historical meeting where the speaker will be speaking about time capsules. While there Amanda is kidnapped and Frank is dumped at the Hotel's ruins.  Amanda finds herself among others who were also kidnapped in a cabin in the mountains.  To be released, they are instructed by a voice over a loudspeaker, they must win the game.  A game of which the learn the rules piece by piece.