Blood Dungeon Arenas & Unlock Order
Blood Dungeon has six arenas and they open in a fixed chain: beat the first boss of one and the next one unlocks. You do not need a full clear to see something new. Every link below is stated by a Steam achievement, so you can check the chain yourself on the game's public stats page.
Unlock rates pulled:
The unlock chain
Catacombs → Pit → Corridor → Boiler → Tombs → Flood
Layouts are hand-authored and fixed. Enemy spawns and most pickups move between runs, but the map itself does not — which is why arena knowledge behaves like permanent progression.
| # | Arena | Opens when | First boss cleared by | Final boss cleared by | Money |
|---|---|---|---|---|---|
| 1 | Catacombs | Starting arena | 87.0% | 13.2% | Not documented |
| 2 | Pit | Defeat the first boss in Catacombs | 67.6% | 10.0% | Not documented |
| 3 | Corridor | Defeat the first boss in Pit | 53.4% | 10.1% | Tight. Launch-day breakdowns describe Corridor as the arena where you lean hardest on enemy drops rather than buying power. |
| 4 | Boiler | Defeat the first boss in Corridor | 48.2% | 8.7% | Not documented |
| 5 | Tombs | Defeat the first boss in Boiler | 43.8% | 4.7% | Generous. Tombs hands out far more money than the other arenas, so it is the one where buying your way into power actually works. |
| 6 | Flood | Defeat the first boss in Tombs | n/a — no achievement marks Flood's first boss | 1.0% | Not documented |
The percentages are the share of Steam owners holding the matching achievement, pulled 2026-08-30. They are the closest thing to a public difficulty curve this game has: 87% of players clear the first boss in Catacombs, 1% clear the final boss in Flood.
Arena by arena
1. Catacombs
- Opens: Starting arena
- Gates: Pit — awarded by the achievement "Pit", for defeating the first boss in Catacombs
- Final boss: Achievement "Decoy" — defeat the final boss in Catacombs — held by 13.2% of players
- Economy: Not documented
2. Pit
- Opens: Defeat the first boss in Catacombs
- Gates: Corridor — achievement "Corridor"
- Final boss: Achievement "Murderist" — defeat the final boss in Pit — held by 10.0% of players
- Economy: Not documented
3. Corridor
- Opens: Defeat the first boss in Pit
- Gates: Boiler — achievement "Boiler"
- Final boss: Achievement "Krug" — defeat the final boss in Corridor — held by 10.1% of players
- Economy: Tight. Launch-day breakdowns describe Corridor as the arena where you lean hardest on enemy drops rather than buying power.
4. Boiler
- Opens: Defeat the first boss in Corridor
- Gates: Tombs — achievement "Tombs"
- Final boss: Achievement "Kill Zone" — defeat the final boss in Boiler — held by 8.7% of players
- Economy: Not documented
- The only arena with a documented middle boss: the achievement "Hypnomancer" is awarded for defeating the second boss in Boiler (17.0%). Fully exploring Boiler awards "Multiheal" (41.6%).
5. Tombs
- Opens: Defeat the first boss in Boiler
- Gates: Flood — achievement "Flood"
- Final boss: Achievement "Procrastinator" — defeat the final boss in Tombs — held by 4.7% of players
- Economy: Generous. Tombs hands out far more money than the other arenas, so it is the one where buying your way into power actually works.
6. Flood
- Opens: Defeat the first boss in Tombs
- Gates: End of the chain
- Final boss: Achievement "Battery" — defeat the final boss in Flood — held by 1.0% of players
- Economy: Not documented
- Fully exploring Flood awards "Crystalize", held by 1.5% of players — the second-rarest exploration marker in the game.
The Daily
A separate daily run sits alongside the six arenas. Playing it once awards the achievement "Vampire Ring" (16.2%). The 26 August 2026 hotfix specifically fixed Bone Shop powers not coming back after a daily run finished, so daily runs and your permanent upgrades do interact.
Clearing everything
The rarest achievement in the game, "Bunkhouse", asks you to beat every level with every character from the bunkhouse. 0.1% of players hold it.
If you are working through the chain, the practical order is the one above — the boss timing rules apply identically in every arena, and every permanent upgrade you buy at the Bone Shop carries forward.