In Forge of Empires, Promethium marks the introduction of special goods in the Arctic Future era and becomes a cornerstone of progression in subsequent ages. It’s not a resource you can trade or farm in your city it must be extracted via the Arctic Harbor by sending special crews on voyages. As you advance through eras like Oceanic Future, Space Age Mars, and beyond, Promethium remains essential for unlocking technologies. Understanding where it comes from, how to optimize voyages, and why it matters can give every player a competitive edge.
What Is Promethium and Why It Matters
The Role of Promethium in Research
Promethium is introduced in the Arctic Future era and remains a required special resource in all subsequent ages, including Oceanic Future, Virtual Future, and Space Age Mars. It’s needed for research, negotiation in later Guild Expeditions, and unlocking campaign map provinces. Unlike standard goods, Promethium can’t be traded or plundered from other players.:contentReference
Where Promethium Comes From
The only way to produce Promethium is via the Arctic Harbor (and later the Oceanic Terminal when entering Oceanic Future). This building allows players to dispatch crew members who bring back the special goods from expedition voyages. Initial yields are modest, but improve with upgrades and crew optimization over time.:contentReference
Unlocking the Arctic Harbor
Required Research
Before you can use the Arctic Harbor, you must research Promethium Extraction in the tech tree of the Arctic Future. Once completed, the Harbor is built on a small island next to your city grid, allowing you to begin expeditions immediately.:contentReference
Upgrading the Harbor
The Harbor can be upgraded through additional techs like ‘Arctic Mining.’ Upgrades increase trip speed, ship capacity, and crew slots boosting efficiency. For example, the second upgrade reduces voyage time to ~18 hours and expands crew selection from five to six potential members.:contentReference
Choosing Crew for Maximum Output
Crew Roles and Effects
Crew members have various abilities that influence Promethium gathered, trip duration, ship health, and bonus rewards like diamonds or Forge Points. For example, Miner roles boost Promethium yield, Navigator roles speed up travel, and Engineer roles reduce ship damage.:contentReference
Pairing and Synergy
Crew members that share relationships such as siblings (Twins) or groups of three (Triplets) enhance each other’s secondary skill. Hiring such combinations improves overall voyage performance.:contentReference
Leveling Crew for Greater Returns
Every voyage awards experience to the crew. As they level up, their bonuses become stronger yielding more Promethium or faster voyages. A balanced crew leveling strategy is key to long-term gains.:contentReference
How Much Promethium Can You Gain?
Daily Average and Growth
New players often start with ~50 Promethium per day. As crew levels increase and Harbor is upgraded, returns climb to around 80100 per day on average. Reddit users report yields between 95 and 105 Promethium per voyage in later stages.:contentReference
If You Keep Aging Up
Although Promethium is introduced in Arctic Future, it remains useful in later eras. Cards like Space Carrier will produce random special resources daily, often Promethium even in later ages. Bonuses from AI Core also enhance multiplies on yields.:contentReference
Strategy Tips for Efficient Collection
Finish the Arctic Continent Map First
Completing the Arctic Future continent map before advancing helps you earn immediate Promethium and reduces future travel delays. Many players recommend clearing these maps to prepare for further aging.:contentReference
Use Powered-Up Space Carrier
Once you reach Oceanic Future and beyond, the Space Carrier becomes a vital source of Promethium and other goods. Leveling it quickly can provide daily returns, even if it only delivers small amounts per trip. Some players even delete and rebuild it to farm more.:contentReference
Upgrade AI Core for Boosts
AI Core grants a percentage-based bonus to all special resource yields from the Harbor and the Space Carrier. Higher-level AI Cores are especially beneficial during Promethium-heavy eras.:contentReference
Balance Speed vs Volume
Depending on your needs fast tech progress vs maximum resource gathering you might choose faster crew combinations (short durations) or yield-focused crews. Players often recommend early specialization on miners, then shifting to faster voyages once yields stabilize.:contentReference
How Much Promethium Do You Actually Need?
Pushing through multiple tech eras requires substantial Promethium. For example, completing all technologies in the Space Age Mars (post-Arctic/Oceanic ages) requires ~1,350 Promethium. Meanwhile, Virtual Future tech needs over 2,700 more. As you approach endgame ages, cumulative demands may exceed 10,000 Promethium.:contentReference
Common Pitfalls and Warnings
No Trading or Plundering Promethium
It is impossible to acquire Promethium through trading or as loot from other players. The only sources are the Harbor, occasional continent map nodes, and the Space Carrier.:contentReference
Ship Damage Reduces Output
Every voyage inflicts wear on the ship, reducing efficiency. Failing to repair regularly increases trip time and decreases returns. Repairing costs Arctic Future goods, so maintain a repair budget.:contentReference
Lengthy Grind Ahead
Growing your Promethium stockpile takes considerable time often several months per age without shortcuts. Players often speak to the monotony of camping in future eras just to gather sufficient resources.:contentReference
Practical Progression Flow
Typical Timeline
- Unlock Arctic Future and the Arctic Harbor via research.
- Complete artctic continent map for early Promethium boost.
- Upgrade Harbor and build crew; begin regular voyages.
- Level crew to improve yields and shorten trip durations.
- Once ready, advance to Oceanic Future and unlock Oceanic Terminal similarly.
- Build and level Space Carrier and AI Core for sustained special resource gathering.
Resource Forecasting
Estimate your daily Promethium yield and calculate roughly how many days are needed per era. Reddit users estimated averages of 6070 per day, meaning gathering thousands of Promethium may take weeks or months depending on crew efficiency and upgrades.:contentReference
Promethium is more than just another resource in Forge of Empires it’s a gatekeeper that controls access to entire eras of advanced technology and units. Since it can’t be traded, you’re entirely dependent on smart Harbor management, crew selection, and strategic aging. From unlocking the Arctic Harbor to upgrading crew abilities, every decision impacts your Promethium yield and speed of progression. While the grind is real often requiring patience over months efficient use of the Space Carrier and AI Core can ease the path. Understanding these mechanics helps turn the Promethium grind from tedious into manageable, giving players agency over their pace and progress through the endgame eras.
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