Last Fortress: Underground APC and Base Progression Guide

To maintain steady base expansion in Last Fortress: Underground, focus investments on your Control Center, Research Labs, and storage facilities while keeping all Armored Personnel Carriers (APCs) continuously deployed on the world map. Concentrating materials on core progression structures prevents resource bottlenecks and keeps tech upgrades moving forward without unnecessary downtime.

Shelter Facility Upgrade Priority

Shelter facilities should be upgraded based on their direct contribution to your base economy and technology tree. Upgrading every facility evenly drains materials and slows progress toward higher-tier unlocks.

Facility	Priority Level	Focus & Purpose
Control Center	Highest	Core progression bottleneck; unlocks higher facility level caps.
Research Labs	Highest	Run 24/7; prioritize construction speed and gathering bonuses.
Storage Warehouses	High	Upgrade before production rooms to prevent resource cap waste.
Production Rooms	Medium	Upgrade in tandem with storage to sustain daily facility costs.
Defense Rooms	Low	Upgrade late; offers minimal return during early growth phases.

Upgrade Execution Order

Keep the Research Lab operating constantly. Prioritize technologies that reduce construction durations or enhance resource gathering speed on the world map.
Upgrade Storage Facilities whenever your resource stockpiles approach maximum capacity. Uncapped production goes to waste if warehouses cannot store incoming materials.
Advance the Control Center as soon as prerequisite facility requirements are met.
Delay heavy investment in defense structures until core production and research milestones are established.

APC Capacity and Troop Management

Maximizing APC efficiency requires balancing troop numbers against exploration risk to avoid costly retraining periods.

Reach the 600-Troop Capacity Milestone: Aiming for 600 troops per APC significantly increases gather mission success rates and combat survivability. Higher troop counts lower soldier casualty rates during routine gathering.
Scale Exploration Distance to Casualties: If APCs return from missions with heavy casualties, shorten your map exploration radius. Resume longer trips only after research nodes or hero bonuses increase squad survivability.
Eliminate Idle APC Time: Any APC sitting in base is lost potential. When not assigned to active combat operations, send APCs out to gather high-demand materials like food or iron.

Hero Lineups and Map Gathering

Hero selection directly impacts gathering efficiency and combat sustainability. Rather than spreading experience thin across a large roster, concentrate resources into a dedicated main lineup.

Team Lineup Strategy

Combat Lineups: Pair durable frontline tanks with high-damage dealers and healing or defensive support heroes to sustain long pushes through tough map content.
Gathering Squads: Assign heroes with stamina-reduction skills or travel-speed bonuses to out-of-base gather teams to shorten world map gathering cycles.
Resource Reallocation: If combat progression stalls, consider resetting secondary hero investments to redirect gear and experience levels into your primary squad.

World Map Gathering Rules

Identify your specific material shortage—typically food or iron—and direct APCs exclusively to those resource tiles.
Select high-tier resource tiles only if your APC troop capacity can clear them quickly without sustaining heavy losses.
Priority-gather from temporary event nodes on the map whenever available to gain bonus materials.