It can frequently happen that you wish to either weaken or completely wipe your opponent out. No matter if you want to settle disputes between you and an alliance mate, wage war on an opponent player or if you wish to simply expand, you will need to attack other islands with your military. You can attack with your land units or with your sea units. Ships are needed for the naval battles, whereas the army invades the target isle, razes the defence buildings (stone wall, main building, and watch tower) and thus paves the way for conquering the isle.

To attack an isle, you assemble a fleet and an army of the single units. You have to bear in mind that you cannot send more land units than room is provided by the small and large troop carriers which you add to the fleet. All this can be arranged in the port menu. The land units have to be trained in the barracks, and the sea units are built in the port. You also need to enter the coordinates of the target isle. When you click the "Send fleet" button at the bottom of the port menu, your fleet - along with the land units if you added them - is sent to the target isle.

When the attacking fleet reaches the target isle, the defending fleet (if there is one) meets the attacker at the port entrance, and a naval battle begins. On both sides, the unarmed ships do not participate; the attacker cannot mix an attack fleet with merchantmen and spy ships, anyway, and on the defending side, all unarmed ships (spy ships, merchantmen, troop carriers, colony vessels) remain in the port.
If the defender is successful - i.e. all armed ships of the attacker are destroyed - the unarmed ships in the attacking fleet (i.e. troop transporters and the colony vessel) withdraw and sail back home. The troop transporters, however, can be attacked if, on the defending side, corvettes have survived the naval battle. The major part of the transporters always comes home, including the units that were sent on them.

If, however, the attacker is successful - i.e. if all armed ships on the defender´s side have been sunk - the remaining attack fleet attacks the outriggers, which defend the port gate. If they are also sunk, the troop carriers will enter the port, and the land units will disembark.
Now, the attacking army moves forward towards the city, causing damage to the watch tower while mainly attacking the stome wall, which is defended by the defending land units on the isle. Thus, the stone wall increases the defence value of the isle. As soon as the stone wall is torn down and the remaining defending land units are wiped out, the remaining attacking force moves on to and then attacks the the main building. Once the main building is razed, the isle can be conquered.
If a colony vessel had been sent with the attacking fleet, and the main building has been razed, the isle is automatically conquered and it´s now yours.

IMPORTANT: Even if there are no more defending units on the isle, you can not conquer an isle without a colony vessel in your invading force. It must also be considered that an "empty isle" is not entirely defenceless, and that a coloy vessel has absolutely no attack power. Therefore, the coloy vessel can shatter at the coast and be lost. So, a coloy vessel always needs an armed escort, and, of course, troop carriers that bear land units to the isle.

An attack can cause collateral damage. Buildings can be damaged, and inhabitants or workers can get killed.

In a nutshell:

• military ships only fight other sea units (including outriggers) - this applies to the attacker and the defender (with the difference that the defender, of course, does not attack the attacker´s outriggers).
• if all the attacking ships are sunk, the attack is over, but the land units in the troop carriers are not lost
• land units only fight land units and destroy buildings (stone wall, watch tower, and main building)

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