There must be 50 answers. Here are a couple off the top of my head: --Humor is the most obvious thing. --Accessible language. Some of the dialect may be difficult and of course some of the lingo is dated. But by and large Twain is crystal clear. --Good stories. He's a gripping yarn spinner. Never forget that the two most famous "kids' books" are titled "The Adventures of...." and "Adventures of....." --And here's one more special trait that has always struck me: In Tom Sawyer and Huckleberry Finn Twain strikes almost the perfect balance for kids between reality and wish fulfillment. It's perhaps more obvious in the earlier book: Tom gets the girl, gets rich, runs away and gets away with it, attends his own funeral, bosses the other kids around, etc., etc., etc. All those wonderful things a kid might dream of doing..... BUT Tom also takes his lumps. He's a very real child as he squirms through an endless school day or a Sunday sermon, is forced to wash, to wear nasty clothes. He feels guilt and a good deal of shame, and fear (even terror). He makes a fool of himself... and that list too could be greatly expanded. It's a truly wondrous blend of "Tom is the kid I would love to be!" and "Tom is like me!" Mark Coburn