Core: Citadel

Core: Citadel is the highest-tier Erekir planetary core. As an Erekir core it provides large item storage, substantial health and armor, and enforces Erekir-specific behavior: it destroys any items placed inside that are not used for constructing buildings, and it requires a full underlying network of core zones beneath every tile it will occupy in order to be built or upgraded.

The Citadel occupies a 6×6 footprint and is designed as a late-game supply hub on Erekir maps. Its key statistics are 30,000 health, 15 armor, and 4,000 item capacity. Like other Erekir cores, its contribution to allowable active units is fixed at +15 (Erekir cores do not increase max active units with each tier the way Serpulo cores do). The Citadel’s high build cost is intentionally larger than the item capacity of the previous core tier, encouraging players to construct multiple cores across a map rather than relying on a single upgrade path.

Because Erekir cores automatically incinerate any stored items that are not used for building blocks, the Citadel must be used primarily as a construction logistics hub rather than a general-purpose warehouse for arbitrary resources. Planning storage and conveyor layouts around what is actually consumed by your base’s buildings avoids unexpected losses. Upgrading an existing core into a Citadel requires that core zones (the map-specific underlying tiles that permit Erekir core upgrades) exist underneath every tile the Citadel will occupy; you cannot upgrade if any required tile lacks the core zone.

Practical notes and strategies:

• Ensure a complete core-zone footprint before attempting an upgrade; try placing and verifying zone coverage early when expanding toward a Citadel-sized site.
• Use multiple cores across the map to distribute storage and construction throughput, since a Citadel’s high build cost and the Erekir design encourage several smaller hubs rather than a single megaplex.
• Keep only construction-relevant items routed into the Citadel to avoid them being incinerated; use dedicated container arrays or request-routing to filter resources.
• Take advantage of the Citadel’s armor and high health by placing it behind defensive layers or integrating it with turrets—its durability makes it a natural anchor for frontier bases.
• Remember that, unlike Serpulo cores, upgrading to an Erekir Citadel does not increase maximum active units beyond the standard Erekir value, so plan unit production and support accordingly.