Some excellent advice on what units to build for what houses (assuming full tech level): Ordos: Get that starport going nice and quick, and get some missile tanks on defence. Use only a few deviators, they're not economical in large numbers. Saboteurs are very useful, get'em fast, they can really disable an enemy base if you chose your targets well. For the rest, combat and siege tanks will do. Atreides: Get sonics on line early, but only make such a number of them so they can stand in a line with little chance of flanking attacks, because they're as dangerous against friendlies as against enemies. Behind them, mostly missiles and sieges are required, though try to keep them well behind. Ornithopters are a must, but be careful about rocket turrets and try and take out a building per strike. Harkonnen: Devastators are a must for offence and defence. Due to their poor range, on defence they are best when supported by missiles and sieges behind them. Death Hands, as the only totally invulnerable unstoppable fighting units in Dune, should be used on crowded bases and areas. Use these orders, and you may find yourself on the non-routed side.