Game Mechanics

Resource Chains

Resources are produced through a tiered chain system. Basic resources feed into processing buildings that create increasingly valuable goods. Higher-tier buildings require catalyst resources that can only be obtained from special locations and high-level outposts.

Basic Resources

Produced by the foundational buildings on your estate. These feed everything else in the chain.

Refined Resources (Estate & Outposts)

Refined resources are the connective tissue of the economy: almost every Tier 1+ processing building requires them. You can produce them two ways.

On your estate (the steady floor): your Lumbermill, Quarry and Mine begin refining automatically once they reach level 5, producing a small amount of the matching refined good each tick on top of their raw output. This costs no extra building slot and consumes no raw resources. Output grows with building level, so levelling these buildings is the simplest path to refined materials.

At outposts (the high-throughput ceiling): refining structures (level 3+ structures) consume 4 base resource per tick and produce 2 refined per tick (2:1 conversion), at much higher volume than the estate floor. Outposts are the way to scale refined production once you want serious throughput.

Tier 1 — Processed Goods

Tier 2 — Advanced Goods

Tier 3 — Luxury Goods

Catalyst Sources

Four catalyst resources are produced exclusively by special locations and level 6+ outposts. Every Tier 2 and Tier 3 chain (except Weaving Workshop) requires at least one catalyst as an input, so securing the right special locations is a strategic priority for any estate aiming at advanced production.

Estate Development

Growing your estate from Village → Hub → City raises your building-slot cap (20 / 35 / 55) and is run as a staged construction project from the Buildings → Development tab — not a single click-and-wait.

Each upgrade is divided into four phases. Opening the construction site is free; you then fund each phase individually with its own resource bundle. A funded phase builds on its own timer, and when it finishes you claim an interim reward into your reward chest and unlock the next phase. The four phase timers add up to the full upgrade time (12 hours for Hub, 48 hours for City).

On the estate canvas, a construction scaffold rises through the phases so your progress is visible. Claiming the final phase upgrades the tier, grants a Battle Pass XP burst, and raises a permanent landmark on your estate (a Hub charter post or a City Ringmür watchtower) that other players see when they visit and admire your estate.

Combat Overview

Combat in Imperia Borealis revolves around two core stats: Offensive Power and Defensive Power. When armies clash, each side's total power determines how many casualties the other side suffers.

There are several combat contexts in the game: estate raids (PvP), bandit camps, special location garrisons, and outpost garrisons. Most modifiers apply across all types, with some being context-specific.

Casualties are damage-conserving: the kills a stack suffers are proportional to the damage it actually takes. A unit needs damage equal to its Defensive value to fall. Whole kills always land, and any leftover damage becomes a chance at one more kill, but only when that leftover is at least 10% of a unit's health.

A wide range of modifiers affect these calculations. Every modifier stacks multiplicatively, so they compound rather than simply adding together.

Combat resolves through a 6-phase system (Enter Battle → Positioning → First Attack → Charge → Main Attack → Withdraw), where units with specific keywords act in different phases. For the full breakdown of phases and all 16 combat keywords, see the Combat Guide.

Unit Base Stats

Each unit type has base offensive and defensive values. These are the raw numbers before any modifiers are applied.

Building Bonuses

Barracks

Each level of barracks provides a +5% bonus to both offensive and defensive power for all your units, up to a maximum of +50% at level 10.

Pillaging

After a successful attack on an estate, the attacker steals a percentage of the defender's resources.

Gear & Equipment

Equipment is assigned to individual units. If you have 50 militia and 30 iron swords, only 30 of those militia benefit from the sword bonus. The bonus scales proportionally to the fraction of equipped units.

Weapons

Tier progression: Iron → Reinforced → Steel. Each tier replaces the previous one on the unit.

Armor

Keyword-Granting Weapons

Advanced weapons unlocked through the knowledge tree grant combat keywords to equipped units, changing how they fight in the phase-based combat system. When only some units of a type are equipped (e.g. 30 of 50 militia have crossbows), the army splits: equipped units fight with the keyword, the rest fight normally.

Monk & Shaman Auras

Religious units provide passive aura bonuses to your entire army, not just their own combat power.

Rituals

Rituals are temporary, powerful effects activated by spending faith. Some are available to all followers of a religion; others require specific specialization perks.

Base Rituals (Available to All)

Perk-Unlocked Rituals

Specialization Perks

As you progress along a religious specialization path, you unlock passive bonuses and powerful rituals. You may only choose one perk per tier. Below are all perks that directly affect combat.

Berserker Path (Aesir — Offense & Raiding)

Paladin Path (Christianity — Defense & Garrisons)

Other Paths with Combat Effects

Tool Buffs

Consumable tools crafted at the workshop can provide temporary combat effects.

Bounty Board

The Bounty Board is a daily PvE campaign system, gated behind the Bounty Hall building. It gives players a structured combat path that does not require attacking other estates.

• The board rotates once per UTC day and is identical for every player, so leaderboards and conversation align around the same set of contracts.
• Each day offers 6 bounties: 3 easy, 2 medium, 1 hard. Difficulty determines step count, payout, and recommended army size.
• Bounties are multi-step campaigns — a mix of combat raids, timed siege phases, caravan dispatches, and expert assignments.
• Only one active bounty at a time. Abandoning starts a cooldown before the next can be accepted.
• Rewards arrive as claimable chests: resources, gear blueprints, battle-pass XP, and cosmetics. A completion bonus is granted once every step is claimed.

Territory & Alliance Modifiers

Defenders benefit from geographic and alliance advantages. These bonuses apply only to the defending side.

Border Defense

When defending in a border parish, defenders receive a +15% bonus to defensive power.

Alliance Buildings

Parish Quest Effects

Active parish quests on a defender's estate can grant variable defensive bonuses.

Foreign Trader at Visby

A visiting Hanseatic merchant docks at Visby with a rotating daily stock of finished luxury goods — and, on some days, a rare gear blueprint. The stock refreshes at midnight UTC and is the same for every player that day. It exists to give landlocked and non-coastal estates a guaranteed path to luxuries they cannot produce at home (the catalyst chains behind amber, stained glass, and similar goods are coastal-only), even when no other player happens to be selling them.

Prices are deliberately steep and paid in base resources (wheat, stone, lumber, iron ore), so it is an expensive fallback rather than a cheap shortcut. You buy by sending a caravan to Visby to collect the goods, exactly like accepting any market listing, so you need a trading post and an idle caravan. Each offer stays available to everyone until the next rotation.

The Bryte's Report

When you return after 2+ hours away, your estate steward — the bryte (Old Norse bryti, the overseer who ran a lord's estate in his absence) — reports what passed: the most notable event front and centre (battles, returned ships, milestones), a tally of what your estate produced and endured, and what stands ready for your orders. At most one report every 6 hours.

Night-market salvage: if your storage overflowed while you were away, the bryte sells part of the surplus and converts it to Battle Pass XP — 1 XP per 40 value-weighted units (higher-tier goods weigh more), capped at 150 XP per day. Upgrading warehouses is always better than letting goods spill, but lost production is never a total loss.

Kontör & Hanseatic Ports

Established estates can convert surplus production into gear, blueprints, experts, and cosmetics by dispatching merchant ships to four foreign Hanseatic ports out of the Kontorhuset building. Each port has its own preferred cargo, reward category, and risk profile:

Each port has its own talent branch that resets at season end, so investing in a port is a season-scoped commitment. For ports, holds, jackpot odds, risk modifiers, and the talent tree in full, see the Kontör Guide.

Modifier Stacking Order

All combat modifiers stack multiplicatively and are applied in the following order:

1. Base unit stats (offensive & defensive values)
2. Barracks bonus (+5% per level)
3. Gear bonuses (per unit type, scaled by equipped fraction)
4. Monk / Shaman auras (capped army-wide bonus)
5. Specialization perk multipliers (passive offensive / defensive)
6. Ritual multipliers (temporary faith-powered effects)
7. Enemy weakening (e.g. Intimidation reducing enemy defense)
8. Territory & alliance bonuses (defender only)
9. Tool combat buffs (e.g. Battle Brew)

Casualty reduction sources (Guardian, Battle Hardened, Martyr's Blessing) stack additively with each other, then reduce the final damage taken.

Season Surfaces

Each season runs in its own realm with a fixed end date. While core mechanics carry over, several systems are season-scoped and reset when the season closes — giving every league a clean finish line and a fresh status race.

Season Leaderboards

Personal Wrap & Season Titles

The Season tab shows your personal rank on both Merchant and Privateer boards plus headline stats (tier, battle pass tier, admires received, titles earned). At season close, the top 1 Most Admired estate earns a unique season-tagged title, with ranks 2–5 receiving the season's runner-up title. Reaching 100 lifetime admires grants the "The Admired" title at any time.

Further Reading

The mechanics on this page are summaries. Each system below has its own dedicated guide:

• Combat Guide — the six combat phases, all 16 keywords, and per-unit damage timing.
• Knowledge Guide — the four knowledge paths (Warfare, Production, Commerce, Parish), node costs, and expert study.
• Specialization Guide — the six religious paths and how perks and rituals chain together.
• Outpost Guide — building, upgrading, and defending parish outposts (plus level 6+ catalyst output).
• Kontör Guide — the Hanseatic merchant trade, holds, jackpots, risk, and seasonal talents.