Last Fortress: Underground Base Building and Hero Progression Guide

To prevent progress bottlenecks in Last Fortress: Underground, balance your base facility upgrades with a focused hero deployment plan. Clear rubble to unlock room tiles, keep your main power plants leveled up so electrical failures do not freeze production, and split your hero roster between base management and wasteland operations.

Managing Shelter Infrastructure and Power Grid

Your underground shelter relies on continuous power to keep production facilities operational. If your power grid fails due to insufficient capacity, your base facilities stop working until energy levels are restored.

To establish a stable facility grid:

Clear rubble and debris from newly opened subterranean areas to reveal building tiles.
Construct fundamental facilities, including power generators, kitchens, and water purification units.
Group similar production rooms near one another to optimize output efficiency.
Upgrade your power plants ahead of facility expansions to satisfy electrical demands.

Always prioritize upgrading your Main Control Room whenever base conditions allow. Upgrading this central hub unlocks higher-tier building options, specialized room facilities, and advanced hero training options.

Balancing Resource Production and Consumption

Base progression requires a steady supply of three key resources: food, water, and building materials. Over-expanding base facilities without sufficient output leads to operational deficits.

Check your current production versus consumption rates in the main menu before committing to major facility upgrades or research initiatives. Keep production in surplus through these primary methods:

Internal Production: Keep kitchens and water purification units staffed to maintain stable baseline supplies.
Wasteland Exploration: Send squads on expeditions to harvest rare materials that cannot be produced inside the shelter.
Technology Tree Research: Direct your early research points into worker gathering speed and warehouse storage capacity to compound long-term yields.

Assigning Heroes for Base and Wasteland Duties

Heroes support your refuge through combat performance and passive facility bonuses. Because characters assigned to field expeditions cannot work inside the shelter, you must rotate your roster based on active tasks.

Hero Focus	Key Assignment	Primary Value
Base Production	Shelter Facilities	Grants passive production boosts to specific production rooms.
Wasteland Combat	PvE & Base Defense	Clears threat nodes, secures high-tier loot, and defends shelter walls.

Save your hero shards for high-tier recruits, but level up a foundational core squad early to handle immediate defensive needs. When preparing for wasteland combat, compare your total squad power against the node's recommended power level. If your squad falls below the requirement, upgrade combat skills and gear rather than risking defeat, which triggers extended unit recovery times. Ensure combat squads travel with adequate medical supplies, as deployed field squads cannot be instantly recalled once engaged in long expeditions.