Furnace upgrade costs — every level and every Fire Crystal tier

The Furnace is the building every other building is capped by, so the only real question in this game's mid-game is how far away the next Furnace level is. Two things change once you reach Lv 30:

• Levels stop being numbered and become Lv 30-1 to 30-4, then restart as Fire Crystal 1 to 10, each with four sub-steps of its own.
• From Lv 30-1 on, Fire Crystal is the hard bottleneck — not Meat or Wood. You can have every resource capped and still be stuck.

Build time below is the raw value with no construction speed bonus and no speedups applied. Treat it as a ceiling, not a forecast.

Fire Crystal tiers

Read this table as bands of five, not as single levels. Lv 30-1, 30-2, 30-3, 30-4 and FC 1 all cost exactly the same; the price only steps up when you start FC 1-1. Same again from FC 1-1 through FC 2, and so on. So the moment your Fire Crystal income clears one band, it clears the next four levels too — which is why people who plan by band finish a whole tier while people who plan level-by-level stall.

Two things worth knowing before you get there. Refined Fire Crystal first appears at FC 5-1, not earlier — everything below that is plain Fire Crystal, and plenty of guides get this wrong. And at each whole tier from FC 6 on, the plain Fire Crystal cost roughly halves while Refined doubles: FC 6 wants 100 plain and 20 Refined where FC 5-4 wanted 200 plain and 10. The whole-number levels are the cheap ones.

What Century Games does publish about Fire Crystals

The cost table above is not official — nobody's is. But the rules around it are, and these four lines are quotations, not estimates.

The third row is the one that costs real money in practice. Plan the build before you press it — in this era, starting an upgrade "to see" burns half your crystals and every speedup you fed it.

For ordinary buildings: levels are raised through the furniture inside them and the Furnace level, and upgrade materials come from assigning survivors, Hero Exploration, missions, field gathering, recruitment and the shop. No building produces Steel — it comes only from Hero Exploration, Intel missions and packages, which is why Steel is the thing that blocks you first.

Sources: Fire Crystal unlock conditions · Where Fire Crystals come from · Refunds when cancelling · Fire Crystal buildings and troops · How building upgrades work · Upgrade materials · No buildings produce Steel

The rules above are the publisher's. The cost table is not — Century Games has never released one. We compiled it by cross-checking independent reference tables and kept only values that agreed across sources. If a row disagrees with your own client, tell us and we will re-check it.