The crystals are required to unlock new realms in Dark Legacy.
Each subsequent Realm requires a greater amount of crystals to unlock. All Realms are connected to Sumner's Tower. Not to be confused with Obelisks, which are used in Gauntlet: Legends to unlock new areas.
- The white and black crystals are the only crystals to not be provided in excess, there are only 225 and 250 of them hidden in the realms respectively without repeating levels.
- The purple and black crystal are not depicted in the HUD crystal icon that appears when you collect a crystal.
- Dream World is the only realm out of the eight realms to not include any crystals due to it being the last out of the eight.
- Yellow crystals appear before green crystals, despite green crystals being used before yellow crystals. A single yellow crystal can be collected in Poisoned Fields before green crystals make their debut in Ghost Town.
- Yellow crystals, white crystals and black crystals all are introduced in the first level of the first three realms respectively. Each of these levels only contain 1 of the respectively coloured crystal.