An image of City Hall.

City Hall Tasks are a series of competitions that cycle throughout the day. At any given time, there are 3 events running. As soon as an event ends, a new one is randomly chosen from a pool of about 20-30 different events.
You start off with access to only 1 event at a time, but will unlock the 2nd and 3rd event slots by collecting medals as explained below.
 
Starting at level 11 you will be able to complete daily tasks in the City Hall for rewards and a chance for fantastic prizes. Accessing the City Hall by the Mayor's Aide will open a panel with a list of available tasks that you can complete. These tasks are changed regularly, with new tasks rotating in as older tasks go out.
 
Each task has a set of conditions and a time limit (as displayed in the top-right corner of the task). As you perform actions in the game that fulfill the conditions of that task, your score for that particular task will increase and the task bar will begin to fill up. If the task bar passes a reward icon, then you can select that icon in the task panel to collect the reward. Once the timer runs out the task will expire, and any progress or rewards will be lost, so be sure to collect your rewards before then!
If you score particularly high in a given task you may earn one of the placement prizes as depicted in the Leaderboard section of the event information. Earning one of these prizes will require you to achieve a higher score than other participating players, and competition is pretty fierce, so be sure to give it your all!
 
When City Hall tasks are first unlocked you will have access to one daily task at a time. As you succeed in tasks they will gradually acquire medals, which will unlock the ability to complete more tasks at once. Once a total of three tasks at a time have been unlocked, every 50 medals you earn can be exchanged for a prize by selecting the prize icon next to the medal count, and then selecting the "Claim" button to exchange those medals for the prize!
 
 

Objectives

Each event has a variety of objectives to do around your town that you can complete for points.
An image of City Hall Task objectives
 
 

Milestone Rewards

Each event has three milestone rewards:
  1. Cash
  2. Fertilizer
  3. Diamonds
Each milestone you hit also earns you a City Hall Medal - each set of 50 medals you collect can be redeemed for a reward!
Once you've collected 50 medals, tap the reward to the right of the medals bar, then tap the "claim" button!

An image of City Hall Task milestones

 

Leaderboard Rewards

You can also compete for Leaderboard Rewards:
  • 1st Place
  • 2nd Place
  • 3rd Place
  • Top 5%
  • Top 10%
  • Top 20%

An image of City Hall Task leaderboards