As mentioned above, Alliances are initially formed by a Treaty between two Nations, with the official name of the Alliance being derived from the Treaty name. Once an Alliance is created, those first two members can invite up to three additional Nations to join the Alliance for a maximum of 5 Nations per Alliance.

Being in an Alliance means your members have their own chat channel! Type /ch a to join Alliance Chat, which is only visible to the members currently in the Alliance. When a Nation leaves an Alliance (which does not require a Treaty Proposal) they lose access to this chat.

An Alliance's war status is tied together - meaning that if one Nation in the Alliance declares War (or has War declared on them), then all members of the Alliance join that War - so be careful who you ally with! Your fates are tied together on the world stage.