A Rally is an attack by a team against a single enemy, meaning that you can unite your corps members to attack an enemy together.

When putting together a Rally team, the initiator needs to set a departure time for the combined forces. Team members' troops should arrive before the time and then will set out together to find their target.

To initiate a Rally attack, you need to build a Joint Command. The total number of troops that can participate in the Rally attack depends on the Joint Command level of the initiating player. 

Only the initiator can disband the rally troops; once the troops depart they cannot be recalled.