This guide tries to help veterans by itemizing changes that occurred over the years.
It basically gives you a set of "points" that you can use in a day, and each attack takes certain amount of points. Effectively, this means that once you use up your points, you cannot attack and must wait.
Because we know not all players like this, we have realms that do not have this new mechanic, and some that do.
Realm with this mechanic, are labeled as "1 hour per day" or "30 minutes per day" and indicate how many points you get. A 30 minutes per day realm, means that, roughly, if you spend 30 minutes playing on a realm, you will be just as competitive as a person who spends 10 hours, attack wise.
Realm with morale are typically called "Veteran" realms, realms without morale, are typically called "Veteran-insane" realms.
The effect on the game play are significant, and you have to adjust your play style to it.
The following videos explain the reasoning behind this mechanic, and explain how to use it