WARNING: Playgrounds of the Mind contains about 99% recycled material.Sometimes, when a writer gets older, they start recycling their work. Heck, some of them even do it when they're young. They put out book after book of short story collections in which a large numbers of the stories are duplicates from previous editions, and only a few of the stories are new.It's sleazy, of course; basically an obnoxious way to rip off the reader. Unfortunately, in his declining years Larry Niven started doing this in a big way.Playgrounds of the Mind includes short stories from a number of excellent Niven collections. If you don't have those books, they're well worth reading - but I'd recommend picking up those earlier books, not this one.It also includes a lot of excerpts from various Niven novels. Personally, I find this extremely annoying for two reasons: one, I already own all those novels. Niven made me pay for the same material twice, and that indicates a real contempt for his readers. I'd excuse it as simple senility and greed, but Playgrounds of the Mind was published in 1992 - and Niven has written a good novel or two (and several mediocre ones) since then. Although admittedly those books were all written with collaborators; for all I know, Niven may effectively be a vegetable by now, and the novel that I took as a sign that he "still had it" might actually just be a successful counterfeiting of his classic style by his co-author.The second reason that I am irritated by Playgrounds of the Mind is that novel excerpts rarely work as stand-alone stories. Yes, many of them are from Niven's better work. But effectively, they're just a set of teasers - if you like them, you'll need to buy the original novels to get completion. Again, this is simply reader abuse.There is a very small amount of new material in Playgrounds of the Mind. Niven also included introductions for most of the material, usually at least a couple of paragraphs; for hard-core Niven fans, that's interesting. So this book wasn't completely a waste of my money. And given its massive size, it's a moderately useful "traveling" book, one that I can take on a vacation to read. But that's in part because I won't mind too much if it's damaged or lost.If you're new to Niven, you'll probably enjoy this book. But I'd suggest trying one of his original short story collections instead, such as Tales of Known Space. If you can't find it in a bookstore, your library is sure to have it. If you like it, you'll be pleased to know that Niven is a rarity, an outstanding short-story writer who also wrote great novels. Just try to stick to his earlier work...say pre-1990.