When an armistice agreement is initiated it prevents other players from initiating any new attacks on any of your planets for a certain period of time or until you attack another player. It will not prevent attacks that have already been sent by others. When active there will be a visible shield surrounding all the protected planets.
Note however that the time starts from when you enter your commander name not after, if you waste several hours on that, you will naturally have less armistice time than others.
After Server MergeEdit
When a server merge occurs 24 hours of Armistice Agreement is given to all affected commanders.
An armistice agreement is available as an item bought from the store, but is also provided in some other situations.
After being attacked a player's planets can receive shielding for a period of time from 4 hours to 24 hours, depending on the severity of the attack (although not fully understood, it is determined by the amount of resources stolen and personal scores of players involved)
Battles however not always grant armistice agreements as result.