One of the best ways to earn additional resources and other benefits is to participate in activities. One of the buildings included in a new city is the activities building, and it is located just to the left of the citadel, and appears to sparkle.
The menu tells you which activities are currently in effect and when new activities will be available. Some activities do not require you to activate them. The Zombie Siege activity requires an alliance member to activate it. Warning - the loss of troops in an alliance that is unprepared for the Siege activity can be crippling.
Clicking on an activity that is underway reveals several things including your current score, your alliance’s current score, and a list of actions that earn a score. The rewards for meeting benchmark scores can also be seen by clicking on the packages.
The actions necessary to score a variety of points in that activity will also be displayed. It may be a short list of items, or a very long one. It may call for combat, or building, or spending resources and diamonds.