OHMU War Machine is a 1992 game published by TBA Games. Gameplay. "OHMU War Machine" is a game in which battalion and regimental level encounters are conducted using Oversized Heavy Mechanized Units. Reception. Robert DeVoe reviewed "OHMU War Machine" in "White Wolf" #48 (Oct., 1994), rating it a 3.5 out of 5 and stated that "This would be a great system for people who already have an interest in tabletop warfare, or for a group whose members wish to pool their money. This would be a great game for tournaments."