To join an Alliance, your Main Headquarters has to be level 5 or higher and the Alliance Dock has to be restored. After that you can join an Alliance or create your own.
An Alliance can have up to 50 members.
All members have access to the Alliance chat, can donate resources to the Alliance bank, speed up the buildings construction and researches in the Laboratory and attack the opponents.
Alliance Leader determines the conditions of joining the Alliance, manages the Alliance account and team members, builds and upgrades objects on the Aircraft Carrier, assigns mercenaries on the Carrier, declares war and chooses buff for Laboratory's researches. An Alliance can have only one Leader.
Officers manage the Alliance account and the team members (except other officers), build and upgrade objects on the Aircraft Carrier, assign one mercenary on the Carrier, declare war and choose buff for Laboratory's research. An Alliance can have up to five Officers.
Defenders can assign 1 mercenary to the Carrier. An Alliance can have up to 10 Defenders.
Privates have common rights of the Alliance members.
Carrier is the Alliance territory. It is necessary to start a war. The following buildings are situated on the Carrier:
Command Center. Determines the Alliance health points, opens access to new buildings. Destruction of the Command Center means the destruction of the Carrier.
Cannons. Defend the Carrier.
Uranium Factory. Produces a definite quantity of uranium needed for building and upgrading objects on the Carrier every 4 hours. Upgrading the Factory increases its efficiency.
Laboratory. Researches take place here. The researches concern all members of the Alliance. To gain access to more advanced researches, upgrade the Laboratory.
Storage. Storages keep resources necessary for upgrading buildings on the Carrier.
Also you will have to build a deck repair to upgrade the Carrier.
Alliance members can donate resources to equip the Carrier. For regular donations members get rewards. Leaving the Alliance, members take back their unused donated resources.