Realm Dungeons are a gameplay feature in Final Fantasy Record Keeper. They are the main type of dungeon accessible in the game.
Realm Dungeons are themed after prominent areas in the Final Fantasy series. Realm Dungeons are divided into two difficulty levels, Classic and Elite. Compared to Classic Dungeons, Elite Dungeons have a higher difficulty level, Stamina cost, and may have more restriction Medal conditions when facing the boss of the dungeon, if any. When the player completes a Classic Realm Dungeon, they unlock the next Realm Dungeon in the chain as well as the Elite version of the same dungeon. While the Classic versions of Realm Dungeons must be unlocked in sequence, the Elite versions are unlocked and can be attempted in any order the player likes.
To facilitate navigation of the Realm Dungeons, the player can view them in two formats; gateways, and a flowchart. The gateway style organizes stages according to the Realms, and displays statistics for the total number of stages in that realm for both Classic and Elite difficulties, how many of each the player has completed, and how many they have mastered. The flowchart style displays the characters and Memory Crystals available from a dungeon and which dungeons are unlocked by previous ones and which ones they unlock upon completing. Selecting a dungeon in either display mode will the dungeon's difficulty, stamina cost, and First Time completion rewards; if the dungeon has been completed already, Mastery rewards are displayed, as well as if they have been earned or not. The player can change between the two display moves with icons at the top of the screen.
Up until March 2018, Realm Dungeons allowed the player free usage of Roaming Warriors in the dungeon. At the end of February 2018, this was removed in favor of allowing players to choose from a number of pre-set Roaming Warriors provided by the game, which change depending on the difficulty of the dungeon being attempted.
While sequels and spin-offs are grouped with their base game for purposes of Record Synergy, in Realm Dungeons they are grouped separate: for instance, Final Fantasy X and Final Fantasy X-2 are their own Realms. However, Record Synergy are still shared between such titles.
The main reason to complete Realm Dungeons, aside from general level grinding and acquisition of items, is to procure Stamina Shards. Acquiring five Stamina Shards increases the player's maximum Stamina by 1, and refills the Stamina gauge. This is the only way to increased maximum Stamina in the game and Realm Dungeons are the only type of dungeon to reward them, save for a handful of shards available for purchase in Fat Chocobo's Gysahl Exchange.
March 2018 saw a substantial update to Realm Dungeons, making a large number of characters and their Record Crystals more accessible, and increasing the rewards from the dungeons. Mythril and Stamina Shard rewards were unchanged. To compensate players who had already completed a number of Realm Dungeons and could not acquire the updated First Time and Mastery rewards, the developers rewarded such players with a number of other items, depending on how many Realm Dungeons they have completed before the update.
Realm Dungeons are regularly updated with new content. Following each update a Relic Draw is also released, typically featuring Relics for the games whose Realms got new stages in the update. This Relic Draw is always a one-time offer and is half-priced at 25 Mythril for 11 items. For a week's time following such updates, Realm Dungeon stamina costs are halved.