Military School is a feature in The Sims, console versions and The Sims Bustin' Out. Children whose grades stay at F for too long are sent to Military School. The Military School is never seen in game, so children who are sent there will never be back. In effect, being sent to Military School is the child equivalent of an adult leaving after losing a fight, so there is no way to get them back, other than to exit without saving. Once the lot is saved after the child has left, the child is completely removed from the game, and cannot be recovered, even with cheats.