When you see the blue horn on the upper left of your screen, it means that a member of your alliance is receiving an attack.
The displayed time, is the remaining time, until enemy troops reach the target.
You can support your ally, by sending troops to his castle:
1. Click on the targeted castle and then click on “support” button.
2. Choose from which of your castles you want to send troops and click OK.
4. Also, choose which of your available commanders you wish to use and click OK.
a. Choose for how long you want your soldiers to stay inside the supported castle (A). This is important. You must add this value to the travel time of your troops, so they will not leave your ally’s castle, before enemy’s attack. e.g. If travel time of your troops is 1 hour and the alert horn displays 3 hours, then you must choose the 6 hours option. So, travel time (1 hour) + station time (6 hours) = total (7 hours) > horn alert time (3 hours).
c. If the displayed travel time (C) is bigger than the time displayed within the alert horn, then your troops will not arrive in time, to help your ally.
6. Click OK, and your soldiers will depart.