Gem, also known as ruby, is the premium currency in Shadow Fight 2, which are accepted as a mode of exchange throughout the game. They are also the only currency used in the Underworld. Gems can be used for every item for which coins can be used. In addition to that, gems can buy special items in the game which are not purchasable using coins. This is especially true of those items which are readily enchanted by the game. But gems are secondary in the sense that they are more difficult to obtain than coins and players can easily run out of gems because the amount won/bought is quite limited. Players start with 9 gems at the beginning of the game (50 in the Special Edition).
Gems have some distinct advantages over coins. They are:
- Gems can buy all items which coins can, except Knives. In addition, gems can also buy super items that are usually enchanted, and which are not available for purchase using coins.
- When buying or upgrading using gems, the game does not set a delivery time and the items are ready to use immediately after their purchase.
- The items that only can be bought with gems also can only be upgraded to a higher level by using gems. This also applies to challengers' weapons, special events items, boss weapons, and Mythical Sets.
- The energy bar can be fully restored using 5 gems.
- Gems can be used to skip the delivery time that of items are bought or upgraded using coins.
- The Perk Tree can be reset using 35 gems.
- Gems allow the players rematches after losing to a Challenger.
- After winning a stage in Ascension, gems allow the players to spin the lottery again after their first spin.
In Underworld, they can be used to:
- Purchase consumables like Charges, Elixirs, Shadow Orbs and tickets for Ascension.
- Buy keys for bosses.
- Skip waiting time when fighting a boss.
- Skip the timer for daily quests.
- Buy packs and special chests.
- Create a clan.
Gems can be obtained by these methods:
- Facebook Sign up: 5 gems are given after signing up with Facebook for the first time.
- Game tutorial: When the player's energy bar gets empty for the first time, Sensei will award them with 5 gems to refill it; however, the player is forced to refill their energy with the gems given and cannot skip.
- Boss Fights: Defeating a demon boss for the first time awards 3 gems.
- Achievements: Most achievements when they are completed will award the players one gem each. Some Eclipse achievements will award 3 gems.
- Tapjoy offers: Completing a task offered by Tapjoy will offer certain amount of gems to the player determined by the task. Players can access this through the "get free gems" option from the gems section of the shop. This method may not really offer gems after the completion of the task.
- Watching Ads: The game rewards 1 gem for watching of each ad that can be viewed in the same section of the Tapjoy offers or at the bottom left of the map. Players can get up to 10 gems a day from watching ads.
- In-app purchase: Gems can be purchased online for certain prices determined by the game.
- Raid tutorial: After joining any raid for the first time, the players will be given 5 gems to buy one small Charge of Darkness; however, the player is forced to buy one small Charge with the gems given and cannot skip.
- Raid rewards: By participating in raids, players can get rewards at the end of a season based on their score and position at the leaderboard. If player's score and position is high enough, they will receive a small amount of gems in addition with other rewards.
- Underworld Conqueror's Pack: There is a very small chance to receive either 500, 1000, or 10000 gems upon purchasing the Underworld Conqueror's Pack.
- Special Edition: In the Special Edition of Shadow Fight 2, gems are easier to get and comes in larger amount. They can be obtained as a rewards from Storyline Fights, Survival, Duel, and Old Wounds. Furthermore, boss fights and achievements in the Special Edition awards more gems as well compared to the standard version.