Into The Depths Unlock Order Guide: Best Progression Path

Understanding the Unlock System

Into The Depths features a complex tech tree that governs what buildings, units, and upgrades become available as you explore deeper underground. Unlike many colony sims, the unlock order is not strictly linear—it branches based on the resources you discover and the biomes you conquer. Knowing the optimal unlock order is crucial for avoiding wasted resources and ensuring your settlement can survive the increasing threats found in the lower caverns. The game's Roguelite elements mean each run offers different starting conditions, but a core progression path remains effective for most scenarios.

The unlock tree is divided into three primary branches: Infrastructure, Military, and Exploration. Each branch has dependencies that require specific buildings or research items to be completed before advanced options appear. Your early choices will heavily influence your mid-game efficiency, so planning your unlock order from the start is key to a successful expedition.

Early Game: The First Five Unlocks

Your first priority in any Into The Depths run is establishing a stable resource loop. The initial unlock order should focus on survival and basic expansion. We recommend the following sequence for the first five research projects:

1. Basic Excavation: This unlocks the manual dig command and the first tier of tunnels. Without it, you cannot expand your starting room or access new resource veins.
2. Simple Shelter: This provides the blueprint for basic bunk beds. Colonists without sleep will quickly become inefficient and unhappy, leading to productivity loss.
3. Mushroom Farming: Food is a constant concern. This unlock allows you to cultivate glowcaps, a reliable early-game food source that doesn't require light.
4. Water Condensation: This research enables the construction of a moisture collector. Clean water is required for both cooking and basic medical care.
5. Stone Cutting: This allows you to refine raw stone into building materials. It is a prerequisite for most defensive structures and advanced workstations.

Following this order ensures your colony has the essentials: space, rest, food, water, and materials. Do not be tempted to rush military tech before you have a stable food supply, as starving colonists cannot fight.

Mid Game: Branching into Military and Specialization

Once your basic needs are met, the optimal unlock order shifts toward specialization based on your current biome and the primary threats you face. At this stage, you should have unlocked the Workshop and Basic Forge. Your next unlocks should be:

• Reinforced Walls: This is a non-negotiable defensive upgrade. Many early-game enemies can break through simple stone walls, but reinforced walls buy you critical time.
• Spear Crafting: The first dedicated weapon upgrade. Spears allow your colonists to attack from behind walls, reducing damage taken.
• Advanced Smelting: This unlocks better metal alloys, which are required for all mid-game tools, weapons, and armor. It also improves the efficiency of your forge.
• Scout Training: This unlock improves the speed and stealth of your explorer unit. Faster exploration means you can locate valuable resource nodes and boss lairs more quickly.
• Healing Salves: A medical upgrade that significantly improves recovery speed from injuries. Without it, a single fight can incapacitate a colonist for several days.

At this point, you should also consider unlocking the Trading Post if you have encountered a merchant faction. Trade can supplement resource shortages and provide rare items that are difficult to craft.

Late Game: Unlocking High-Tier Units and Boss Prep

The late game in Into The Depths is defined by preparing for the final boss of the current depth layer. The unlock order here becomes critical for survival. You should prioritize the following:

• Heavy Armor Forging: This is a prerequisite for your tank units. Without heavy armor, your front line will be decimated by boss area-of-effect attacks.
• Ranged Weaponry (Crossbows): Before unlocking firearms, crossbows provide a significant damage boost with manageable resource costs. They are ideal for kiting slower enemies.
• Alchemical Refining: This unlocks potions and buffs. A stockpile of strength and regeneration potions can turn a difficult boss fight into a manageable one.
• Fortification Blueprints: These advanced walls and traps are essential for creating a killbox or defensive chokepoint. They deal damage to enemies that attack them.
• Resurrection Shrine: The ultimate safety net. This expensive unlock allows you to revive a fallen colonist once per run, preventing a total party wipe during the final encounter.

This unlock order assumes you have maintained a steady supply of rare minerals. If you are lacking a specific resource, consider unlocking the Deep Mining tech earlier to access deeper ore veins.

Common Unlock Order Mistakes to Avoid

Many players make predictable errors when choosing their unlock order in Into The Depths. Avoiding these pitfalls will accelerate your progress:

• Rushing Firearms: Gunpowder weapons are powerful but require complex supply chains for ammunition. Stick with crossbows until you have a dedicated production line.
• Ignoring Storage: Unlocking advanced technologies before expanding your storage capacity leads to resource waste. Always research Large Storage Racks before heavy production upgrades.
• Neglecting Light Sources: Darkness attracts hostile creatures. Unlocking Luminous Beacons early in the mid-game reduces random attacks and improves colonist mood.
• Over-Specializing: Do not unlock only military tech. A balanced approach that includes infrastructure and exploration keeps your colony running while you fight.

Final Tips for Optimal Progression

The best unlock order is one that adapts to your specific circumstances. If you are playing on a higher difficulty, prioritize defensive unlocks even earlier. If you are aiming for a speedrun, focus on exploration and resource gathering tech. Always check the Research Panel for dependencies—some advanced unlocks require two or three prior researches that may not be immediately obvious.

Finally, remember that Into The Depths is a Roguelite. If your first unlock order fails, learn from it and adjust. Each run provides knowledge that makes the next one more efficient. For more detailed information on specific units and enemies, check out our enemy types guide or our beginner tips page.