All players start with 500 free gems upon starting "Clash of Clans" for the first time. In addition, players can earn more gems by accomplishing in-game achievements and removing obstacles that randomly spawn in their villages.
Players earn the initial 500 gems during the tutorial phase of "Clash of Clans." Although a step in the tutorial encourages players to use 250 gems to finish a building construction, players can choose to wait out the construction to conserve gems. The game tutorial further urges players to speed up production and completion of troops and other buildings by using gems, but players can choose to save the gems for more important purposes, such as acquiring more builders.
"Clash of Clans" features several achievements for players to obtain, and each one has varying gem rewards. For example, upgrading the town hall for the eighth time, earning 1,250 trophies through multiplayer battles and reaching the master league reward players with 20 gems, 450 gems and 1,000 gems, respectively. The highest amount of gems that players can receive in a single achievement is 2,000.
Alternatively, players can clear obstacles in their villages to receive free gems. These include rocks, trees, logs and other vegetation. Clearing an obstacle gives players between zero and six gems. Most obstacles re-spawn once removed, giving players a continual source of free gems.