This novel was first published in 1981 and I read it not long after. I thoroughly enjoyed it then, and was pleased to return to it when it was selected for the Modern Science Fiction discussion group, particularly since I remembered nothing about the plot.
The story is set on Earth some time in the future; there are ultra-high-speed trains running in evacuated tunnels and life-like holograms, but not much else in the way of advanced technology. The location is the Dream Park of the title, a huge leisure park which, in addition to more familiar attractions, hosts role-playing games on vast sets, their actual topography enhanced by computer-generated holograms so they seem to stretch for miles. Keen role-players participate in these games, in which the Lore Master, the leader of the players, pits his wits against the Game Master who devises the game and supervises its progress. Games last for several days during which the players remain on the set and maintain their chosen roles – warrior, thief, cleric or magic user – the magic users being able to summon holographic "supernatural aid" at need. A lot of money rides on these games because, if deemed successful, they are turned into computer games and other merchandise.
The plot concerns the running of a new game, seen as a "blood match" between the Game Master and Lore Master, who have clashed before. Most of the action happens on set, but there is a parallel plot concerning the murder of a security guard at Dream Park, which seems to be associated with the game. The Park's Head of Security, Alex Griffin, becomes convinced that one of the players must have been responsible so he anonymously joins the game as a player in order to try to identify the criminal. However, he finds the game a lot more absorbing than he ever imagined.
I had better start by admitting that I have never participated in a role-playing game of any kind; I'm not sure if that's a benefit or a handicap in reviewing this story! The writing style is brisk and well suited to the teenage market. At first I was disappointed because I found the tale rather frustrating. Many characters are introduced in quick succession and I soon lost track of them. A list of characters is included at the front of the book but, while an essential reference, this only gives their names and roles. Not enough information is provided to round out the personalities or fix their descriptions in the reader's mind, so I kept flipping back though the text to find where they were first (albeit only briefly) described. This lasted until about half-way through the book, during which time I still felt that I didn't know the characters or much care what happened to them.
However, after that the story begins to take off. The surviving characters become more familiar and the story more gripping as the players battle their way through the obstacles and dangers set by the Game Master towards a still-unknown goal in the fantastical world of Melanesian mythology and the Cargo Cult. At the same time Griffin, who secretly keeps in daily contact with his security team, is trying to identify the criminal. The game is a lot more successful than the rather cursory solution of the crime; the eventual revelation of the killer was more of a "huh?" than an "of course!" moment, as not enough clues had been provided.
Despite these reservations, it's an unusual and exciting mix of adventure and crime story, worth the time to read if you can get past the initial problems with characterisation. I expect that RPG fans will enjoy it even more.