Gems

Gems are items used in the Angry Birds Series used to buy content.

Angry Birds Classic
Gems are the rarest currency in the game. In the game, they can be used to buy the following things: They can be obtained in the following ways:
 * Coins
 * Prize Eggs and
 * TNT Shield Power-Up.
 * By passing a league in the Mighty League;
 * Inside Prize Eggs
 * Completing 5 levels in an episode.
 * By buying them in the shop with real money.

Angry Birds GO!
Gems are a secondary currency in the game. They can be obtained in the following ways; They can be obtained in the following ways:
 * To purchase refill energies;
 * To upgrade karts and
 * To open Premium Toolboxes.
 * Gem.png × 40''' to open 1 prize.
 * Gem.png × 400''' to open 11 prize.
 * Inside toolboxes.
 * By buying them in the shop.

Angry Birds Transformers
Gems are a secondary currency in the game. They can be used for the following things: They can be obtained by the following ways:
 * Speed up and complete upgrades;
 * Recharges;
 * Open missions;
 * Purchase Accessories;
 * Destroy difficult levels (which can only be used a matter of three times; each use increases the number of gems needed for the next attack);
 * Unlock covered levels to play bonus coin doubler levels and
 * Change your Transformer into a different Transformer from an event for 1 gem.
 * Through completing achievements.;
 * Through completing missions;
 * Inside Treasure Chests;
 * By buing them with real money;

Angry Birds Fight!
Gems are a secondary currency in the game. They can be used for the following things: They can be obtained as rewards after battles or by buying them.
 * Refill Energy;
 * To unlock birds immediately using 6 Gems.
 * To open Mighty Eagle's Treasure Box using 6 Gems in the Slot game.

Angry Birds POP!
Gems are a secondary currency in the game. They can be used for: They can be obtained in the following way;
 * Buying costumes for the birds.
 * As rewards in events.

Angry Birds 2
Gems are the primary currency in the game. They can be used for the following things: They can be obtained by the following ways:
 * Opening Chests:
 * AB2_Premium_Chest.png Rare - Costs AB2_Gems.png × 80 to open
 * AB2_LegendaryChest.png Legendary - Costs AB2_Gems.png × 900 to open, used to be 24 rare chests
 * Play the Tower of Fortune;
 * Continuing a Tower of Fortune Run:
 * First Pig: 20 AB2 Gems.png
 * Second Pig: 50 AB2 Gems.png
 * Third Pig: 100 AB2 Gems.png
 * Fourth Pig: 200 AB2 Gems.png
 * Fifth Pig: 400 AB2 Gems.png
 * Sixth Pig: 800 AB2 Gems.png
 * Seventh Pig: 1,600 AB2 Gems.png
 * Eighth Pig and onwards: 3,200. AB2 Gems.png
 * Buying Lives;
 * Buying an bird;
 * As a Reward in Chests;
 * As a Clan Reward;
 * As an Arena Reward;
 * In a Tower of Fortune card.
 * By buying them in the shop.

Angry Birds Action!
Gems are a secondary currency in the game. They can be used for the following things: They can be obtained in the following ways:
 * Revive a Bird and
 * Buy Power-Ups
 * As a reward in the Mistery Reward Boxes;
 * As a reward in Daily Prize Boxes
 * By buying them in the shop.

Angry Birds Evolution
Gems are a secondary currency in the game. They can be used for the following things: They can be obtained by the following ways:
 * Hatch Eggs;
 * Buy Scout Energy;
 * Buy Remaining Items;
 * Buy Event Items and
 * Revive Birds;
 * Defeating Pigs;
 * Defeating Thief Pigs;
 * Defeating Gem Pigs;
 * In Chests;
 * Doing Scout Missions;
 * As Event Rewards and
 * By Buying in the Shop.

Angry Birds Tennis
Gems are used as a currency in the game.