Epicinium is a multiplayer strategy game with simultaneous turns. Each turn consists of a planning phase, where all players decide which orders they want to give their units that turn, followed by an action phase, where players watch as the the orders play out. Each player has limited vision and only sees how an opponent's units act, not why.
The red player has just ordered their Rifleman unit to move around the mountains and into the City owned by the blue player.
You can give up to five new orders each planning phase. If a unit does not complete their order during the action phase, it will continue executing that order in following action phases until it does, or until it is given a new order. Review your orders in the order list (shown bottom right) before pressing the Ready button to proceed to the action phase.
City, Barracks, Industry and Airfield tiles can produce units. Select a tile and right-click it to access these abilities. When a tile produces a unit, the size of the unit depends on the the number of buildings it has, with a maximum unit size of three.
Units cost Morale. Generate Morale by killing enemy units and by destroying or capturing enemy tiles. Capturing a tile also causes your opponent to lose Morale.
Units such as the Rifleman can move across the map and fight other units. Units have limited movement speed but will continue moving in following turns. Ground units will automatically attack enemy units in their path and fire back if attacked.
Rifleman units can capture enemy cities and dig protective Trenches, whereas other units such as Tanks offer more destructive capabilities. Access these abilities by right-clicking a unit while it is selected.
Defeat your opponent by capturing or destroying their City tile. At the end of the game, the winner earns 2 points for each undestroyed City tile and 1 point for each other structure tile left on the map.
Want more? The wiki contains an in-depth exposition of all the mechanics and units in the game.