GARY KASPAROV KNOWS that the best kind of game is a simple affair: it requires minimum equipment, has few rules and-with a little practice-yields hours of play time. The software versions of three classics in Edmark's new Strategy Games of the World CD-ROM (800-320-8379) should satisfy the gaming purist in your house. Aimed at kids 8 to 14, this disc teaches basic strategy through games like Nine Men's Morris, Go-Moku and Mancala. You can play against a friend or, in single-player mode, a PC challenger. In some ways, the computer is the perfect strategy tutor for children: it never gets bored and can't be bribed or bullied. On the other hand, Edmark's program is a kinder, gentler Deep Blue; it always lets you go first, allows you to undo bad moves and-best or all-lets you scale down the difficulty when you're having an off day.