This is a re-release of the original Dream Park novel (the fourth book is scheduled to be released this summer) so I grabbed a Kindle copy to see how well it holds up. Set in "Dream Park", a California amusement park, where one of the major attraction is role playing games (what we now call a LARP--Live Action Role Playing Game). There's holograms and tricks used to make the experience seem realistic, and "game masters" running the game behind the scene. I'm assuming this was the first book mention of this sort of thing, though LARP are supposed to have started in the late '70's.
The book itself is a mystery, as a Dream Park security guard is found murdered while the "South Seas Treasure Game" is ongoing. The Game is a major event, basically a duel between a Game Master and the player's "Lore Master". Set in the South Pacific, its basis is Cargo Cult mythology, which makes a marvelous setting for the game. After the guard is found murdered, the Park's security chief, Alex Griffin, is inserted into the game as a player, since it looks like one of the gamers might be the murderer.
As a mystery, I'm not sure it's that good (I suppose you could figure out one of the criminals before Griffin, though with this reread I had not remembered). What I did remember was how much fun the game itself was, and how much joy Niven and Barnes provided (this harks back to the best of early Niven, which always seemed to me to be about the joy of ideas). I do miss the original cover art (a marvelous scene with the gamers in boats, fighting a sea serpent)
There are two sequels, both of which I've read but don't remember that well, but I may go ahead and try them again. The Moon Maze Game will be released in August.