Every layer in Casualties: Unknown, in order: depth, hazards, temperature, enemies and the gear checkpoints that decide whether you can descend.
Casualties: Unknown Layers: Every Depth in Order
Casualties: Unknown is built as a descent through 11 layers, each 300 metres deep. The demo contains the first five. The full game continues to the surface route and the final laboratory, with the last layers turning the run into a story rather than an endless dive.
This page is the layer order and the progression logic behind it: what each layer demands, what kills you there, and what you should have before you enter. For the demo's moment-to-moment route, use the walkthrough.
Official source: Casualties: Unknown on Steam ↗
The layer list
| # | Layer | Depth | Temperature | Signature threat |
|---|---|---|---|---|
| 1 | Gravel Lands | 0–300 m | 15.0 °C | Cold, geysers, Shade crawlers |
| 2 | Deeper Gravel Lands | 300–600 m | 17.5 °C | Darkness, flooding, Cave ticks |
| 3 | Dried Desert | 600–900 m | 26.6 °C | Heat, oil pools, turrets |
| 4 | Wasteland | 900–1,200 m | 25.8 °C | Radiation, sound cannons, no enemies |
| 5 | Overgrown Depths | 1,200–1,500 m | 21.8 °C | Dense combat, Elder Thornback |
| 6 | Frozen Chasm | 1,500–1,800 m | -30.6 °C | Extreme cold, Snow striders |
| 7 | Fungal Pools | 1,800–2,100 m | 17.8 °C | Rain, fungal radiation, Grabber-shrooms |
| 8 | Crystalline Hollow | 2,100–2,400 m | 18.5 °C | Huge drops, flying Manifestations |
| 9 | Geothermal Vents | 2,400–2,700 m | 20.9 °C | Heat, magma, drones |
| 10 | Where We Must Reach | 2,700–3,000 m | — | Story layer, target technology |
| 11 | Crimson Ascent | 3,000 m+ | — | Return route, Crimson growth |
Temperatures are the layer averages from the game's layer data. Individual caves can swing far outside them, especially in Wasteland, which ranges from -20.4 °C to 38.6 °C.
How depth progression works
Each layer is a vertical slice of roughly 300 metres. You enter at the top, descend to the bottom, and save at the exit. The next layer starts at the bottom of the previous one. Climbing back up is always possible; skipping forward is not.
The demo loops after layer 5. Instead of a sixth layer, the exit returns you to Deeper Gravel Lands. That loop is the demo's endgame: keep the character, keep the stash, keep descending for better gear and harder modifiers. The full game replaces the loop with layers 6–11.
There is no timer that forces you downward. Normal difficulty gives each layer a 60-minute limit, but the limit is generous and the timer is visible. Relaxed gives 120 minutes, Paradise 180, and Unchipped removes the limit entirely.
What each layer demands
Layers 1–2: the supply run
The first two layers are about establishing a baseline: a light, a bag, a canteen, a pickaxe, bandages. Nothing here requires a build. The danger is carelessness — a geyser on a narrow ledge, a tick swarm in the dark, a fall with no splint.
Do not over-invest. Copper and coal are abundant, but carrying 40 kg of ore slows you down and makes the first Cave tick encounter worse. Take what you need for the next two recipes and cache the rest at the pod.
Layer 3: heat and height
Dried Desert is the first layer that punishes a slow character. The chambers are wide, the drops are long, and the oil pools at the bottom are deep enough to drown in. Heat raises thirst, and water is scarce.
Bring two water containers, not one. Bring a splint. Bring a light with a spare fuel source, because the layer's open spaces swallow lantern light. Turrets and landmines make the direct route a bad route; the safe path usually runs along the upper shelves.
Layer 4: the radiation exam
Wasteland has no enemies, which makes it the purest test of route discipline. Radiation sources, sound cannons, coils and spent fuel are all stationary and all visible if you look. The layer's temperature swings mean insulation is as important as cooling.
This is the layer where the health panel earns its place. Watch your radiation dose, your blood pressure and your consciousness. A sound cannon can drop you from full health to zero consciousness in one burst if you are caught in the open.
Layer 5: the combat exam
Overgrown Depths is the demo's difficulty spike. The layer is generous with food, water and tree sap, and it is generous with enemies. Thornbacks charge, Tentacle-plants grab, and the Elder Thornback can remove a limb.
Do not enter layer 5 with a starting machete and a foliage bag. Bring a real weapon, real armour and at least two ways to stop bleeding. The enemies guide covers the boss; the best build covers the stats that survive it.
Layers 6–9: the gear gates
The four layers after the demo are built around environmental extremes rather than raw enemy count.
- Frozen Chasm averages -30.6 °C. Without an ion space heater, a Xaloris or a life-pod, the cold drains you faster than any enemy. Snow striders patrol the open sections, and gunmines punish the obvious path.
- Fungal Pools rains constantly and adds fungal radiation. Grabber-shrooms hold you in place while Overgrown ticks close in. Fungali bungali drop Bunchunk, which is the source of Procoagulant — a strong anti-bleed item.
- Crystalline Hollow is vertical. The drops are enormous, the crystals reflect light confusingly, and flying Manifestations attack from angles you cannot block with a floor-level weapon.
- Geothermal Vents is the heat mirror of Frozen Chasm. Magma, lava geysers and drones that punish standing still. Coldpuff and Spicevine are the local plants.
These layers are where the traits and crafting systems start to matter more than raw damage. Resistance, insulation and medicine matter as much as a rifle.
Layers 10–11: the story turn
Where We Must Reach is the target technology layer. Crimson Ascent is the return route to the surface, with Crimson bushes, Crimtrees, pus sacks and veins. The final lab on Earth resolves the story. This is why the game is not an infinite dungeon: the descent has a destination.
The endings guide covers the story structure without pretending there are more branches than the game supports.
Layer modifiers
Each layer has a 40% chance to roll a modifier by default. The chance can be set from 0 to 100% before a run. Modifiers include Foggy, Hot, Scorching, Cold, Freezing, Flooded, Dried, Rainy, Infested, Ionized and Solar-struck.
A modifier changes the layer's route more than its difficulty number suggests:
- Flooded turns low routes into swimming routes and ruins ore caches.
- Freezing on an already cold layer can kill an uninsulated character in minutes.
- Infested adds enemies to a layer that normally has none, which breaks the Wasteland route entirely.
- Solar-struck adds light but also heat and radiation.
If you are pushing a new depth for the first time, set modifiers to 0%. Learn the layer, then add them back.
Progression beyond depth
Depth is only one axis. A character also progresses through:
- Skill levels. Strength, Resilience and Intelligence each level from 0 to 10 and beyond. XP requirements rise steeply after 10. Strength adds damage and carry weight; Resilience adds stamina and pain tolerance; Intelligence unlocks recipes and improves trade.
- Gear tiers. Hand tools → pickaxe → metal pickaxe → titanium pickaxe. Makeshift rifle → pistol → rifle. Foliage bag → backpack → trauma rig.
- Stash and base. The life-pod is the only safe storage. Caching ore at layer exits is a temporary shortcut, not a permanent base.
- Trader reputation. Traders appear in life-pods with random stock. Intelligence, cleanliness and not pointing a gun at them improve prices.
- Knowledge. The largest progression is knowing which trap sound means run, which plant heals and which mushroom is food.
When to stop descending
Stop and climb back when any of these is true:
- Blood below 4.2 L and no blood bag.
- A fracture without a splint.
- Light source below 20% with no spare.
- Radiation dose rising and no anti-rad.
- Bag full of ore and no food.
The game does not punish retreat. It punishes arriving at layer 6 with a broken leg and a dying lantern.
Depth is the only progress bar that matters. Layer 1 starts at 0 m and layer 5 ends at 1,500 m in the demo.
FAQ
How many layers are in the full game? 11, plus the final lab.
How many layers are in the demo? 5.
How deep is each layer? 300 metres.
Is the layer order random? No. The biome order is fixed; the layout and modifiers are generated.
What happens after the last layer? The story resolves at the surface and in the final lab.
Sources and further reading
Related guides
More Casualties: Unknown Guides
The best mods for Casualties: Unknown, what each one changes, and how to choose mods that will survive the jump from demo to full release.
Every weapon in the Casualties: Unknown demo ranked: damage, swing speed, durability, ammo and which weapon fits which layer.
How blood volume, bleeding rate, tourniquets and transfusions work in Casualties: Unknown, and the order to treat a bleeding limb.
The three playable characters in Casualties: Unknown, what Experiment can do in the demo, and what is actually confirmed about Milky and Dune.
How crafting works in Casualties: Unknown: the five tabs, Intelligence requirements, failure tiers, blueprints and the recipes worth making first.
All six Casualties: Unknown presets plus the 41 custom run settings, with defaults, ranges and the options that actually change survival.
Casualties: Unknown endings explained: the confirmed story goal, the unreleased final layers, what the demo does at layer 5, and what is still speculation.
Every enemy in Casualties: Unknown, its layer, attack pattern and drops, plus the Elder Thornback fight and the traps that kill more players than monsters.