The Alliance Furnace is the most critical strategic asset introduced in Season 2: Polar Storm of Last War Survival. As the temperature in the polar region drops to lethal levels, maintaining this massive heating structure becomes the difference between a thriving alliance and one that is completely frozen out of the competition.

In Last War Survival, you do not "build" the Alliance Furnace in the traditional sense. Instead, it is a structure that must be repaired and then constantly maintained through collective effort. This guide provides a comprehensive breakdown of how to locate, repair, and optimize your Alliance Furnace to ensure your members stay warm and your virus resistance stays high.

Immediate Steps to Enable the Alliance Furnace

For players entering Season 2, the Alliance Furnace becomes available on Day 1. However, the initiation process is restricted to alliance leadership (R4 and R5 members). If you are a regular member, your role begins once the location is set.

1. Locating the Build Spot

The Alliance Furnace is managed through a specific interface. To find it, navigate to the Alliance Menu and select the Alliance Furnace icon. From here, leadership can view the current status of the furnace. If it hasn't been placed yet, the system will prompt the R4/R5 to select a location within a Level 1 territory controlled by the alliance.

2. The Repair Process

Once the R4 or R5 member places the build spot on the world map, it appears as a structure under construction.

  • Dispatching Squads: Similar to building an Alliance Outpost, members must send their squads to the furnace's coordinates.
  • Reinforcement Limit: The repair process typically allows up to 20 reinforcements (squads) at a time. The more powerful the squads and the higher the number of participants, the faster the furnace becomes operational.
  • Coordination: It is best practice to announce the furnace placement in the alliance chat or Discord so that members can quickly fill the reinforcement slots and minimize the time bases spend in the cold without protection.

Understanding the Fuel System: The Role of Coal

A repaired Alliance Furnace is useless without fuel. In the frozen north of Season 2, Coal is the primary currency of survival.

How to Collect Coal

Coal is primarily obtained through:

  • Titanium Alloy Factories: These are new seasonal buildings within your base. While their primary output is Titanium Alloy (used for upgrading your personal furnace), they require coal management and often reward coal through seasonal tasks.
  • Individual Goals: Completing Season 2 missions provides massive coal crates.
  • Dig Sites: Capturing and holding dig sites on the world map generates coal for the alliance over time.

The Donation Mechanic

The Alliance Furnace has a collective "Coal Storage." Every member is expected to donate coal regularly. In our testing and observations of high-ranking warzones, successful alliances often implement a "daily minimum donation."

  • Storage Capacity: The furnace can only hold a certain amount of coal based on its level. For a Level 1 furnace, the storage capacity is 200,000 coal.
  • Donation Strategy: Do not dump all your coal at once if the storage is near full. Coordinate with R4s to ensure there is always enough fuel for the night, especially if a Blizzard is approaching.

Operational Modes: Basic vs. Overdrive

Managing the furnace isn't just about keeping it "on." Leadership must toggle between two primary modes depending on the weather conditions.

Basic Mode

  • Function: Provides a steady, baseline heat output.
  • Consumption: For a Level 1 furnace, this costs approximately 300 Coal per minute.
  • Benefit: Keeps the temperature within the "Safe Zone" for bases located nearby during normal polar weather.

Overdrive Mode

  • Function: Significantly increases heat output (doubling the Celsius increase).
  • Consumption: This mode is extremely expensive, consuming 4x the normal amount of coal (e.g., 1,200/min at Level 1).
  • When to Use: Only activate Overdrive during Blizzards. If left on during normal weather, an alliance can deplete their entire week's worth of coal in just a few hours.
  • Pro Tip: R4s should be assigned "weather watch" duties. Since Blizzards are telegraphed, the furnace should be switched to Overdrive exactly when the storm hits and switched back to Basic immediately after it passes.

Alliance Furnace Level Progression and Stats

The furnace grows in efficiency and power as the alliance progresses. Upgrading the furnace happens automatically as the alliance accumulates Rare Soil from captured cities and dig sites.

Below is the statistical breakdown for the first 20 levels of the Alliance Furnace, which illustrates the scaling requirements for coal and the resulting heat benefits.

Level Coal/Min (Basic) Heat Increase (°C) Overdrive Heat (°C) Overdrive Coal/Min Coal Storage
1 300 3 6 1,200 200k
2 360 3.5 7 1,440 300k
3 420 4 8 1,680 400k
4 480 4.5 9 1,920 500k
5 540 5 10 2,160 600k
6 600 5.5 11 2,400 750k
7 660 6 12 2,640 900k
8 720 6.5 13 2,880 1,050k
9 780 7 14 3,120 1,250k
10 840 7.5 15 3,360 1,450k
11 900 8 16 3,600 1,650k
12 960 8.5 17 3,840 1,850k
13 1,020 9 18 4,080 2,100k
14 1,080 9.5 19 4,320 2,350k
15 1,140 10 20 4,560 2,600k
16 1,200 10.5 21 4,800 2,900k
17 1,260 11 22 5,040 3,200k
18 1,320 11.5 23 5,280 3,500k
19 1,380 12 24 5,520 3,850k
20 1,440 12.5 25 5,760 4,150k

Strategic Placement: The Heat Radius

One of the most common mistakes alliances make is poor base positioning. The Alliance Furnace has a limited range.

The "Warm Zone"

When you click on the Alliance Furnace on the map, you will see a highlighted radius. Only bases within this radius receive the heat bonus.

  • Prioritizing Members: Alliance members with lower-level personal High-Heat Furnaces or those who haven't spent much on temperature resistance upgrades should be given priority spots closest to the Alliance Furnace.
  • Relocation Strategy: During the early weeks of Season 2, coal is scarce and personal furnaces are weak. It is highly recommended to have the entire alliance "huddle" around the furnace. As you move toward the center of the map (the Capitol), the ambient temperature drops significantly. Without being in the furnace's radius, bases will quickly hit the "Frozen" state, which stops resource production and prevents certain military actions.

Moving the Furnace

As your alliance captures new territories closer to the center of the map, leadership may need to dismantle the current furnace and repair it at a new, more strategic location.

  • Downtime Warning: Remember that when the furnace is being moved, there is a period of "zero heat." Ensure this move happens during a period of clear weather, never during a predicted Blizzard.

The Connection Between Alliance and Personal Furnaces

The Alliance Furnace does not work in isolation. It acts as a multiplier for your Personal High-Heat Furnace.

Virus Resistance

Upgrading your personal furnace increases your Virus Resistance, which is required to defeat the evolved polar zombies and elite doom monsters in Season 2. While the Alliance Furnace provides heat, your personal furnace provides the technical resistance needed for combat.

Titanium Alloy Factories

To upgrade your personal furnace, you need Titanium Alloy. To produce Titanium Alloy, you need Coal. This creates a resource loop:

  1. Produce/Collect Coal.
  2. Donate a portion to the Alliance Furnace (for collective heat).
  3. Use the rest in your Titanium Alloy Factory.
  4. Upgrade your personal furnace to survive the deeper, colder zones of the map.

Managing the "Coal Crisis" in Early Season 2

In the first two weeks of Season 2, almost every alliance suffers from a coal shortage. This is because Titanium Alloy Factories are low level and members haven't unlocked enough coal-producing missions.

Conservation Tactics

  • Intermittent Heating: Some alliances choose to keep the furnace OFF during the day when members are active and can manage their own heat, only turning it on at night.
  • The "Overdrive" Trap: Many new R4s turn on Overdrive because they see "Temperature Low" warnings on member bases. This is often a mistake. Members should be encouraged to upgrade their own resistance rather than relying on the alliance to burn through coal reserves.
  • Rare Soil Priority: Since the furnace levels up via Rare Soil, capturing Dig Sites should be the alliance's top military priority. Higher level furnaces are more fuel-efficient per degree of heat provided.

FAQ: Alliance Furnace Management

Who can place the Alliance Furnace? Only R4 and R5 members can initiate the placement or relocation of the furnace.

What happens if we run out of coal? The furnace will shut down immediately. Temperatures for all bases in the radius will drop to the ambient map temperature. Bases will likely begin to "Freeze," significantly slowing down progress.

Does the Alliance Furnace protect against the Virus? Indirectly. While its primary stat is Heat, keeping your base warm prevents "Freezing" debuffs that would otherwise hinder your ability to collect the resources needed to upgrade your Virus Resistance via your personal furnace.

How do I increase the furnace level beyond Level 20? The furnace continues to scale up to Level 30 and beyond. This requires the alliance to capture higher-level cities (Level 6 and Level 7/Capitol) which produce more Rare Soil per hour.

Can enemy alliances attack our furnace? The furnace has a durability stat. While it is not as vulnerable as a base, it can be targeted during territory wars. If the durability reaches zero, it must be repaired again.

Summary of Best Practices

To master the Alliance Furnace in Last War Survival, follow these three golden rules:

  1. Centralize Base Placement: Keep the alliance tight. If a member is outside the heat radius, they are a liability.
  2. Strict Coal Budgeting: Establish a donation quota and never use Overdrive unless a Blizzard is active.
  3. Prioritize Dig Sites: The faster you level up the furnace through Rare Soil, the more efficient your coal consumption becomes.

By coordinating your alliance's coal production and maintaining a disciplined heating schedule, you can survive the Polar Storm and position your warzone for victory at the Capitol.