Into The Depths Mechanics Guide: Core Systems Explained

Core Gameplay Loop: Build, Explore, Conquer

Into The Depths is a roguelite colony sim where each run tasks you with establishing a settlement in the hostile underground. The core loop revolves around three phases: Building your base, Exploring the caverns, and Conquering threats to push deeper. Unlike traditional city builders, death is permanent for your colony, but you retain meta-progression upgrades.

Your journey begins at the surface entrance. You must construct essential structures like a Workshop, Barracks, and Storage Room to support your colonists. Each building requires specific resources, which you gather by sending workers to nearby nodes. The deeper you dig, the rarer the resources, but the more dangerous the environment becomes.

This cycle is punctuated by Roguelite events—randomized encounters, resource droughts, or creature invasions—that force you to adapt your strategy. Successfully conquering a depth layer unlocks new upgrades for your next run, creating a satisfying progression loop.

Resource Management and Economy

Efficient resource management is the backbone of any successful colony. You start with basic materials like Wood, Stone, and Food, but advanced tiers require Iron Ore, Crystal Shards, and Ancient Relics. Each colonist consumes Food daily, so establishing a sustainable food source—through hunting, farming, or trading—is your first priority.

The game features a dynamic economy system where resource nodes deplete over time. You must constantly expand your mining operations to find new veins. Use the Resource Overlay (hotkey: R) to scan for nearby deposits. Prioritize building a Stockpile near your dig site to reduce travel time for your haulers.

Pro tip: Always maintain a buffer of at least 50 units of Food and 30 units of Wood. A sudden crisis, like a cave-in or a blight, can cripple your colony if you are living hand-to-mouth. For more on this, see our resource management guide.

Base Building and Defense

Your base is more than just a collection of buildings; it is a fortress against the darkness. The Defense System is critical. You must place Torches to push back the encroaching gloom, as darkness spawns hostile creatures. Build Walls and Barricades to funnel enemies into kill zones, and construct Watchtowers to give your archers elevation bonuses.

Each building has a Structural Integrity score. If you dig too aggressively without supporting your ceiling, cave-ins will destroy your base. Reinforce with Wooden Beams or Stone Pillars as you expand. The Blueprint Mode (hotkey: B) allows you to plan your layout before committing resources.

For a deeper dive on defensive strategies, check our beginner guide. Remember, a well-planned base can mean the difference between a thriving colony and a premature end to your run.

Combat and Colonist Classes

Combat is real-time and tactical. You control a squad of up to six colonists, each belonging to a unique class. The Warrior excels in melee, the Archer provides ranged support, and the Mage uses area-of-effect spells. You can recruit new colonists by building a Tavern or rescuing them from prison cells found in the depths.

The Aggro System is simple: enemies attack the closest colonist. Use this to your advantage by positioning your Warrior as a tank while your ranged units deal damage. Abilities, like the Warrior's Shield Bash or the Mage's Fireball, have cooldowns and consume Stamina. Manage your party's stamina carefully during prolonged fights.

If a colonist falls in battle, they are lost permanently for that run. However, you can resurrect them using a rare Revival Shrine found in special rooms. For a full breakdown of all classes and their builds, see our class guide.

Exploration and the Depths System

The underground is divided into distinct Biomes: the Crystal Caverns, the Magma Core, and the Abyssal Trench. Each biome has unique resources, enemies, and environmental hazards. The Depths Meter tracks your progress; reaching certain thresholds unlocks new rooms and boss encounters.

Exploration is conducted through a node-based map. Each node represents a room (e.g., "Abandoned Mine," "Goblin Camp," "Treasure Vault"). You can see the rewards and threats before entering. Choose your path wisely—some nodes are dead ends, while others lead to shortcuts back to your base.

Always bring a Grappling Hook or Rope to cross chasms. These tools are crafted at the Workshop. Unexplored areas often contain Ancient Relics, which are used for permanent upgrades between runs. Learn more about the map layout in our map guide.

Roguelite Progression and Upgrades

The true depth of Into The Depths lies in its meta-progression system. Between runs, you return to the Hub, a persistent area where you spend Depth Tokens earned during your expedition. Upgrade your Caravan Capacity to carry more loot, unlock new Starting Gear, or research Blueprints for advanced buildings.

The Prestige System allows you to reset your progress for powerful, permanent bonuses. Each prestige level increases the difficulty but also unlocks unique cosmetic and gameplay modifiers. This system ensures that no two runs feel the same.

For a complete list of all upgrades and their costs, refer to our upgrades guide. Mastering this progression loop is the key to conquering the deepest caverns and achieving victory.