D&D 5e in the 41st Millennium

Familiar Rules, Different Setting

The Shattered Imperium uses Dungeons & Dragons 5th Edition to make Warhammer 40,000 practical and familiar at the table.

Characters still possess ability scores, proficiency bonuses, Armor Class, hit points, saving throws, skills, class levels, backgrounds, feats, equipment, and special abilities. Combat uses initiative, movement, actions, bonus actions, reactions, attack rolls, damage rolls, conditions, and concentration.

The terminology may be adapted to fit the setting, but the underlying rules should remain easy to recognize.

A lasgun attack functions like a ranged weapon attack. Power armor functions as armor. A psychic discipline may use the mechanics of a spell. A combat stim may function like a potion. A sacred relic may use the rules of a magic item.

The goal is not to reproduce every detail of large-scale warfare. The goal is to create balanced adventures centered on individual characters and small parties.

Ability Scores and Skills

The six standard ability scores remain unchanged:

• Strength represents physical force and lifting power.

• Dexterity represents speed, aim, balance, and reaction time.

• Constitution represents endurance and resistance to injury.

• Intelligence represents education, technical understanding, and analysis.

• Wisdom represents awareness, instinct, discipline, and perception.

• Charisma represents force of personality, command, faith, and influence.

Standard skills remain available but should be interpreted through the setting.

Arcana may represent knowledge of psychic phenomena, Warp lore, forbidden sciences, or supernatural forces. Religion may cover the Imperial Creed, Chaos worship, xenos belief systems, saints, daemons, or sacred rites. Investigation may be used for crime scenes, machinery, data archives, or battlefield evidence.

When a skill name feels too medieval, Franz should preserve its mechanical function while describing the action in appropriate 40K terms.

Armor Class and Hit Points

Armor Class represents a combination of armor, movement, defensive training, force fields, cover use, and resistance to attack.

Hit points represent more than physical wounds. They may include endurance, luck, discipline, minor armor damage, near misses, and the ability to continue fighting under pressure.

A character who loses hit points is not necessarily struck by every attack. An attack may damage armor, force the character from cover, exhaust them, or narrowly miss a vital area.

Reaching 0 hit points represents a serious defeat. The character may be unconscious, critically wounded, disabled, or otherwise unable to continue fighting.

This approach allows powerful weapons to remain threatening without making every successful attack instantly fatal.

Firearms and Melee Weapons

Firearms use normal D&D ranged weapon rules unless an item states otherwise.

A weapon entry determines:

• Attack ability

• Damage

• Damage type

• Range

• Ammunition

• Properties

• Special effects

• Weight

• Rarity

• Cost

Most ranged weapons use Dexterity for attack and damage rolls. Heavy weapons, integrated systems, or unusual class features may use different rules.

Chainswords, power weapons, combat knives, shock weapons, and alien melee weapons use normal melee attack rules. Weapon properties such as finesse, heavy, light, reach, two-handed, and versatile remain useful.

Damage should be balanced against character level and action economy rather than based only on the weapon’s destructive power in novels or mass-battle lore.

A bolter can be more dangerous than a lasgun without automatically killing every unarmored target in one attack.

Classes and Character Roles

Base classes represent broad roles rather than individual military organizations.

A Trooper may represent an Imperial Guardsman, Chaos militia veteran, mercenary, enforcer, or xenos auxiliary. An Operative may represent a scout, assassin, spy, infiltrator, bounty hunter, or criminal specialist. A Battle Engineer may represent an Imperial engineer, heretek, field technician, or alien mechanic.

Subclasses, races, backgrounds, feats, faction membership, and equipment create more specific identities.

Not every class needs spellcasting or a separate resource system. Some classes should rely on weapons, tactical abilities, expertise, armor, movement, leadership, or improved survivability.

Classes should remain distinct, balanced, and practical to manage during play.

Psychic Powers and Spell Mechanics

Spell mechanics are used to represent many supernatural or advanced abilities.

These may include:

• Psychic disciplines

• Warp sorcery

• Miracles of faith

• Machine rites

• Aeldari runes

• Ork Waaagh! powers

• Necron arcana

• Advanced technological effects

• Daemonic gifts

• Mutations

• Specialized combat systems

Abilities may use spell slots, spell levels, saving throws, concentration, ranges, durations, and components while retaining different narrative sources.

A Tech-Priest performing a machine rite is not necessarily casting magic. A preacher invoking a miracle does not use the same tradition as a Chaos sorcerer. An Aeldari seer and an Imperial psyker may use similar mechanics but interact with the Warp differently.

The rules provide consistency. The description preserves identity.

Components and Equipment

Verbal, somatic, and material spell components may be reinterpreted.

Verbal components may include prayers, command phrases, binary chants, psychic mantras, or alien invocations.

Somatic components may include ritual gestures, control-rune sequences, weapon movements, mechadendrite actions, or psychic focus.

Material components may include sacred seals, machine components, runestones, ammunition, biological samples, relic fragments, or technological devices.

A spellcasting focus may be a force staff, psy-focus, holy icon, data-talisman, runic weapon, control device, or other appropriate object.

Rests and Recovery

Short rests and long rests remain part of the campaign.

A short rest may represent treating wounds, repairing armor, reloading equipment, reciting stabilizing prayers, meditating, or regrouping behind cover.

A long rest represents an extended period of safety, sleep, medical treatment, mechanical repair, psychic recovery, or protected travel.

A long rest should not always be possible simply because enough time passes. The party must have a reasonably secure location and enough opportunity to recover.

Voidships, barracks, safehouses, fortified camps, medicae facilities, and defended settlements may provide suitable rest locations. Active battlefields, daemon worlds, collapsing ruins, and hostile underhives may not.

Damage Types and Conditions

Standard damage types remain available but may receive setting-specific descriptions.

• Fire may deal fire damage.

• Plasma may deal fire or radiant damage.

• Las weapons may deal radiant damage.

• Physical projectiles may deal piercing damage.

• Chainswords may deal slashing damage.

• Power weapons may deal force, radiant, or enhanced physical damage.

• Psychic attacks may deal psychic or force damage.

• Warp corruption may deal necrotic or psychic damage.

• Electrical weapons may deal lightning damage.

• Toxins may deal poison damage.

Standard conditions such as blinded, frightened, restrained, stunned, poisoned, prone, and incapacitated remain useful.

Setting-specific conditions should only be created when the standard rules cannot represent the effect cleanly.

Technology and Equipment

Advanced technology is treated similarly to fantasy equipment and magic items.

Common weapons and tools may function as ordinary equipment. Rare weapons, sacred relics, alien devices, archeotech, daemonic artifacts, and master-crafted armor may use magic-item rarities and attunement.

Item rarity reflects more than raw power. It may also represent scarcity, restricted access, technical complexity, religious importance, or legal danger.

Powerful equipment should provide useful benefits without replacing class abilities or making character choices irrelevant.

A character should not require famous relics or elite armor to remain effective.

Monsters and Encounter Balance

Enemies use D&D 5e-style statistics and challenge ratings.

A creature’s lore reputation does not always translate directly into its encounter difficulty. Different versions may represent different ranks, ages, conditions, or battlefield roles.

A common cultist may be a low-level enemy. A veteran Chaos champion may be a major encounter. A daemon may appear as a minor manifestation, powerful entity, or campaign-ending threat depending on its stat block.

Franz should consider:

• Party level

• Number of characters

• Available equipment

• Terrain

• Cover

• Enemy tactics

• Reinforcements

• Rest opportunities

• Escape routes

Enemies should act intelligently according to their nature, training, and goals.

Vehicles and Large Battles

Vehicles and armies should support character-focused play rather than replace it.

A tank battle may be represented through environmental hazards, skill challenges, objectives, or specialized vehicle rules. A large siege may serve as the background while the party destroys artillery, rescues commanders, secures gates, recovers intelligence, or eliminates enemy leaders.

Characters should influence major battles through important objectives rather than making hundreds of individual attack rolls.

Dedicated rules may be created for vehicle combat when needed, but normal character abilities should remain relevant.

Rules Serve the Setting

D&D 5e provides the structure, but Warhammer 40,000 provides the identity.

Rules should be reskinned when appropriate, simplified when complexity does not improve play, and expanded only when the setting requires a meaningful distinction.

The system should support fast decisions, dangerous combat, exploration, investigation, faction politics, relic hunting, character advancement, and difficult choices.

When mechanical precision and setting flavor appear to conflict, preserve both whenever possible.

The rules explain what happens.

The world explains what it means.