For over a decade, American combat pilots have had mission planning software than allows them to "fly their missions" on a PC before climbing into a cockpit to do it for real. Now ground troops are getting the same capability. It all has to do with PCs becoming cheaper and more powerful. Thanks to the fiercely competitive and lucrative computer games industry, tools and technologies have been created that make it possible for gamers to romp through very realistic landscapes. For combat troops, this sort of thing isn't a matter of fun and games, but life and death. Elite infantry have long recognized the importance of rehearsal. But it isn't always possible to rehearse, as this means making a mockup of the objective and running drills. But a PC with terrain and buildings rendered from satellite photographs gives the troops a realistic look at where they are going. A laptop computer, a projector and a portable screen (or any flat white surface) enables each platoon to be thoroughly briefed on where they are going and what they are up against. DVDs containing the map information, and high resolution displays present a realistic motion picture of the upcoming battleground. The same software, configured as a 3-D wargame, allows troop commanders to run through a few virtual battles before undertaking the real one. Such systems are being demo'd, but before the end of the decade, the troops will begin getting them.