Which side moves first is determined based on unit morale, leadership, etc. In a phase you may move one unit or all of those within range of a leader unit. Once you have completed a phase, the initiative is calculated again and a new phase begins. Scenarios are typically short, as little as 5 turns, tactical battles for concrete objectives. Each side can control infantry, mechanized units, helicopters, artillery and off-map resources such as naval gunnery units and combat air strikes.
Some units have no ability against one unit type or another.
Ammunition supply is modelled, run out of one type and your combat effectiveness is drastically reduced against that type of target. Attacks can be performed by units separately or in concert. Combat results are spread across all defending units of the type attacked within the target hex. Units may move, fire, or a combination in a turn. Units which move and then attack are less effective in combat than those that simply attack.