Warhammer 40,000: Gladius - Relics of War Boss Guide: Strategies for Every Boss

Q: How many factions are there?

Eleven. Space Marines, Astra Militarum, Orks and Necrons came with the base game on 12 July 2018. Seven arrived as DLC: Tyranids and Chaos Space Marines in 2019, T'au and Craftworld Aeldari in 2020, Adeptus Mechanicus in 2021, Adepta Sororitas in 2022 and Drukhari in 2023. Each ships its own units and its own economic rules rather than being a reskin.

Q: How do you win?

Two ways only. Complete your faction's quest chain, which is a scripted storyline unique to each faction describing what it wants on Gladius Prime, or eliminate every other player. There is no diplomacy, no trade and no cultural or scientific victory, which keeps the mid game aggressive in a way most 4X games are not.

Q: Which faction is best for a first game?

Astra Militarum. They settle anywhere, run a straightforward Food and Ore economy, and their power curve is legible: cheap Guardsmen screens early, Heavy Weapons Squads and Leman Russ tanks in the middle, a Baneblade late. Space Marines are also forgiving but their single Fortress Monastery and Requisition economy behave unlike anything else in the game.

Q: What happens if a resource hits zero?

You are throttled rather than eliminated. If a resource used for building upkeep hits zero while your income is negative, that building's production drops 10 percent per turn until it bottoms out at 50 percent. If a resource used for population upkeep hits zero the same way, population growth degrades on the same schedule. Recovering income reverses it.

Q: How dangerous is the wildlife?

Dangerous enough to plan around. Catachan Devils are tank-sized and hit hard despite moderate armour, so they want anti-tank weapons rather than massed infantry. Psychneuein spawn a new Psychneuein from any unit they kill. Enslavers mind control units below 6.5 current morale and drain 2 morale a turn from adjacent units, and there is exactly one Enslaver squad guarding each artefact on the map.

Warhammer 40,000: Gladius - Relics of War boss guide with strategies, recommended builds, and tips for every boss fight from start to endgame.

EarlyGuides Editorial Team

Researched and editorially reviewed. Updated August 12, 2026.

Proxy Studios and Slitherine shipped the first turn-based 4X game set in Warhammer 40,000 on 12 July 2018, and it strips the genre down to the part 40k actually supports. There is no diplomacy on Gladius Prime: you win by completing your faction's quest line or by killing everyone else. Four factions launched with the game, Space Marines, Astra Militarum, Orks and Necrons, and seven more arrived as DLC over the following five years: Tyranids in 2019, Chaos Space Marines in 2019, T'au in 2020, Craftworld Aeldari in 2020, Adeptus Mechanicus in 2021, Adepta Sororitas in 2022 and Drukhari in 2023. Each one runs a different economy, so switching faction changes far more than the unit art.

Boss fights are where Warhammer 40,000: Gladius - Relics of War tests everything you've learned. This guide covers strategies for bosses across all areas, organized by progression order. For general combat techniques, see our combat guide.

Boss Difficulty Overview

Area	Difficulty	Recommended Build	Key Equipment
Wire weed	Easy	Astra Militarum	Leman Russ Battle Tank
Imperial Ruins	Moderate	Astra Militarum	Leman Russ Battle Tank
Rivers	Hard	Space Marines	Tactical Space Marines
Artefact sites	Very Hard	Space Marines	Tactical Space Marines
Ore fields	Extreme	Space Marines	Tactical Space Marines

Wire weed Bosses

Area difficulty: Easy Recommended level: Matters from turn one to the end of the game Recommended build: Astra Militarum with Leman Russ Battle Tank

Strategy

The first bosses teach core combat mechanics. Focus on learning patterns rather than dealing damage. Ore, Food, Energy, Influence and Requisition are the five, but no two factions use them the same way. This is your primary tool here.

Key tips:

Don't rush. Learn the attack patterns first.
Use Five resources with faction-specific economies to create safe windows.
Leman Russ Battle Tank is enough to handle everything here.

Imperial Ruins Bosses

Area difficulty: Moderate Recommended level: Contested from the early expansion phase onward Recommended build: Astra Militarum with Leman Russ Battle Tank

Strategy

Early game bosses test your understanding of Cities that claim tiles with influence. Players who skipped learning this mechanic will hit a wall here.

Key tips:

Cities that claim tiles with influence is critical for these fights.
Farm Leman Russ Battle Tank upgrades if you're struggling.
Consider switching to Astra Militarum if your current setup isn't working.

Rivers Bosses

Area difficulty: Hard Recommended level: Relevant whenever you plan a multi-turn advance Recommended build: Space Marines with Tactical Space Marines

Strategy

Mid-game bosses are the major skill check. They combine multiple mechanics and punish players who rely on a single strategy.

Key tips:

You need both Five resources with faction-specific economies and Faction quest lines as a victory route mastery.
Tactical Space Marines makes a significant difference. Get it before attempting these.
See our combat guide for advanced techniques.

Artefact sites Bosses

Area difficulty: Very Hard Recommended level: Early to mid game, once you can beat an Enslaver squad Recommended build: Space Marines with Tactical Space Marines

Strategy

Late-game bosses are serious challenges. Build optimization matters as much as mechanical skill.

Key tips:

Make sure your build is fully optimized.
Tactical Space Marines at max upgrade is recommended.
Study each boss's attack patterns. Most have 2-3 phases.

Ore fields Bosses

Area difficulty: Extreme Recommended level: Decides city placement from the first settle onward Recommended build: Space Marines with Tactical Space Marines

Strategy

Endgame bosses are the ultimate test. They require mastery of all combat systems and an optimized build.

Key tips:

Top-tier build with best-in-slot gear is mandatory.
Master every mechanic. See our combat guide.
These fights reward patience and pattern recognition above all else.

General Boss Tips

Learn before you fight: Spend your first attempt observing attack patterns. Don't try to win on attempt one.
Match your build: Some bosses favor certain builds over others. Don't be afraid to switch.
Upgrade your equipment: A max-upgraded Tactical Space Marines trivializes fights that seem impossible with weaker gear.
Use Five resources with faction-specific economies: The core combat mechanic is your best defensive tool in every boss fight.
Check the walkthrough: Our walkthrough tells you when you're ready for each boss.

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