Forge Fuel

Forge Fuel is the coal-based currency that keeps a cell Forge running.

Right-click a placed Forge to load fuel into it, and each unit burns down over time to generate Ancient Energy at the forge's tier rate. The rate scales up as you climb from LOW through VIP. A single forge holds up to 256 fuel, so topping one off lets it produce passively while you're away. It's a bread-and-butter part of cell income alongside generators.

Where to get it: a regular fill in lootboxes and crates.