A player can leave their own nation to join another nation anytime. However, all of the experience points that the player has earned for their own nation will remain with their old nation. What if the player doesn’t intend to return to their original nation, and wants to transfer the XP they’ve earned for their own nation to the new nation they will be joining? This can be done by uniting their original nation into their new nation.
When one nation unites into another, all of the first nation’s XP, land, and members are transferred over to the second nation. The first nation continues to exist, but it is returned to level 1.
A unite costs 500 credits. The cost is first taken from the nation that is being united into; if they don’t have enough credits to pay the cost, then the rest is taken from the nation that is doing the uniting. If the two nations combined don’t have enough credits, the unite won’t be allowed.
Before two nations can unite, they will first need to be allies (see Alliances). You can click (or tap) on a land square belonging to the other nation in the map view, and select Send Alliance Invitation from the menu. Once the other nation accepts your invitation, they will appear in your nation’s list of allies on the Nation panel under the Allies tab. Then, from this panel, either nation can invite the other to unite into it, by hitting the Invite to Unite button. After an invitation to unite has been sent, it can also be withdrawn from this same panel.
The nation that has received the invitation to unite can then either accept it or decline it, also from within the Nation panel’s Allies tab. If they accept the invitation, then the unite will take place — all of the land, XP and members will be transferred out of the nation that accepted the invitation, and into the nation that sent it.
When sending another nation an invitation to unite into your nation, you can make an “offer” — a number of credits that you will pay that other nation, for the privilege of uniting their holdings into your nation. If you do make an offer, then the moment the other nation accepts your invitation to unite, the credits will automatically be removed from your nation and sent to the nation that is uniting with yours. If the other nation does not accept your offer, you will keep the credits. This system allows one nation to pay another for the hard work of earning the XP that will be united into it (without any risk that the other party won’t fulfill their end of the deal). Note that payments for unites can only be made using transferable credits (those that have been purchased, rather than won as rewards). If your nation has no transferable credits, then the option to make an offer will not appear when you send a unite invitation.
A nation cannot unite with another nation within 48 hours of the last time that it united.