Massive Battles: A D&D 5e Ruleset
This ruleset provides guidelines for Dungeon Masters (DMs) to run large-scale conflicts in D&D 5th Edition, from skirmishes involving dozens to full-scale wars with thousands of combatants. It aims to balance epic scope with manageable gameplay, keeping the focus on the Player Characters' (PCs) impact on the battlefield.
Disclaimer: This is a set of House Rules. You will need the fifth edition Player’s Handbook, Dungeon Master’s Guide, and Monster Manual to make full sense of this document.
I. Core Concepts & Overview
Massive Battles are fought on a grid, representing a larger area than typical D&D combat. The key distinction is between Units (groups of creatures acting as one) and Singular Creatures (individual monsters, NPCs, or PCs).
A. The Battle Grid & Scale:
- Grid Type: Square grid (battle mat).
- Square Representation: One square represents 15 ft. (Standard Scale).
- Optional Scales (for Larger/Smaller Battles):
- Very Small: 5 ft. per square (1 creature per token)
- Medium: 25 ft. per square (25 creatures per token)
- Large: 50 ft. per square (100 creatures per token)
- Very Large: 100 ft. per square (400 creatures per token)
- Epic: 200 ft. per square (1,600 creatures per token, 1-minute rounds, speeds/damage x10)
- Consistency: Once a scale is selected, all units use the same scale for the battle's duration.
B. Combatants:
- Units: The primary "characters" of the mass combat system. A group of identical or very similar creatures fighting as a single entity. They receive orders, move, fight, and react as if they were individuals.
- Tokens: Each unit is represented by physical markers (1-inch squares/circles). Each token represents a specific number of creatures based on the chosen scale (e.g., 10 creatures per token at Standard Scale).
- Singular Creatures: Individual combatants that act independently. Represented by miniatures.
- Monsters: Singular creatures not part of any unit (e.g., a Red Dragon).
- NPCs: Non-Player Characters, typically embedded within a unit (e.g., a unit leader, special forces).
- PCs: Player Characters, central to the narrative. Can operate as a Squad (a group of PCs acting as one singular creature for movement tracking).
II. Setting the Stage: The DM's Preparation
Before the battle commences, the DM orchestrates the setup.
A. Army Creation:
- Create Opposing Armies: Define the factions involved and their overall goals.
- Unit Composition:
- Each unit should consist of combatants that are all the same type (same size, speed, similar level/stats).
- An army can have multiple identical units.
- Optional Elements:
- Monsters: Add independent monsters to the battlefield.
- NPCs: Embed NPC leaders, spellcasters, or elite guards within units.
- Player Characters (PCs):
- Command Units: PCs can each command a separate unit.
- Special Forces Squad: PCs can operate as a separate squad to tackle specific objectives, operating as singular creatures.
- Start Embedded: PCs start embedded in a unit, free to leave and move independently later.
B. Battlefield Setup:
- Draw the Field of Battle: Use your battle mat and draw terrain features.
- Terrain: Functions as in D&D 5e (difficult terrain, cover). DMs can add specific restrictions (e.g., disadvantage on flying attacks in a dense forest).
- Structures: Provide cover (1/2, 3/4, total). Units firing from walls have advantage against ground units.
- Placement of Combatants:
- DM & Player Roles: Decide how control is distributed (DM controls opposition, players control allied units/NPCs, or even another group of players controls the enemy army).
- Unit Placement (Defender First, then Attacker): All tokens for a unit must be placed with at least one side adjacent to another token in the same unit, in a relatively compact shape with no "holes." Units cannot overlap. Opposing units must be at least 6 squares apart.
- Monster Placement: Not occupied by a unit. Allied monsters no closer than 8 squares to enemy units, and closer to allied units. Neutral monsters at least 8 (ideally 12) squares away, equidistant from opposing forces.
- NPC Placement: Start embedded in a unit. The unit must have at least one more token than the total number of embedded NPCs.
- PC Placement: Start embedded in an allied unit. If a squad, use a single miniature.
III. Unit Construction & Statistics
The backbone of massive battles is the Unit.
A. Unit Definition:
- A unit represents 10 (at Standard Scale) identical creatures fighting as one.
- Hit Points (HP):
- Unit HP: (Creature's HP) x (Number of Tokens) x (Creatures per Token).
- Token HP: (Creature's HP) x (Creatures per Token).
- When Unit HP is reduced by one Token HP, one token is removed.
- Optional Variant (Lower Hit Points): Each token has the same HP as one typical creature. Damage inflicted by a singular creature on a unit is divided by creatures per token. Damage inflicted by a unit on a singular creature is multiplied by creatures in all attacking tokens.
- Armor Class (AC): Same as a single creature in the unit.
- Speed: Same as a single creature. Calculate squares by dividing speed by 15 (at Standard Scale), rounding up.
- Abilities/Skills: Same as a typical creature, though many may not be used in mass combat.
- Actions:
- Damage Multiplier: Multiply single creature damage by (Creatures per Token) for one token's damage.
- Multiple Attacks: If a single creature gets multiple attacks, a token also gets multiple attacks.
- Targeting: All attacks from a single token in one round must be against the same target.
B. Unit Types:
- Unmounted Units: Infantry, skirmishers, archers. No special bonuses/penalties.
- Mounted Units: Use mount's speed. Advantage on attacks against unmounted units or those without reach weapons. Larger tokens (e.g., 2x2 for men on horseback). If intelligent mounts, their HP are added to the unit's HP.
- Flying Units: Use flying speed. Advantage on attacks against grounded units from above.
- Mobs: Disorganized, low-intelligence units (hyenas, villagers).
- First melee attack is always a charge.
- Cannot form Phalanx Formation or Set Weapons against Charge.
- Ranged attacks: Only tokens with direct line of sight.
- DC 15 Wisdom check before every charge (failure: no attack).
- DC 15 Wisdom check on critical hit (failure: disengage 2 squares, can retry charge next round).
- Routed mobs scatter and cannot be rallied.
- War Machine Units: Special units containing siege weapons, towers, or rams. (See Chapter VII: War Machines for details).
IV. Combat Rounds & Actions
Combat rounds represent 6 seconds. Each unit and singular creature normally gets a chance to act.
A. Initiative:
- Before Combat: Each unit and monster makes an initiative check. Units with an embedded leader (NPC/PC) add their leader's Charisma modifier. Initiative order is set for the duration of combat.
- Singular Creatures:
- Within a Unit: Act on that unit's initiative.
- Entering a Unit: Initiative becomes the unit's.
- Leaving a Unit: Initiative becomes one less than the unit they left.
- PC Squad: When leaving a unit, each PC rolls initiative. The highest takes initiative one less than the unit left, others follow.
- Surprise: Generally not applicable in mass combat due to scale. Use standard D&D 5e rules if appropriate (e.g., for invisible attackers).
B. Movement:
- Each round, a unit or singular creature can move up to its speed and take one action.
- Dash Action: Move up to double speed.
- Pass Through (Units): Can move through allied units up to speed. Must end completely in unoccupied squares. If not, both units forfeit other actions until the first unit fully clears.
- Singular Creatures through Units: Move through allied units freely. Can fight through enemy units (1 square per round). Make a normal melee attack; if at least 1 damage, move into the square.
C. Unit Actions (Move Action & Combat Action):
- Move: Move up to speed, maintaining formation.
- Charge: Move up to double speed (must start 2+ squares away). End adjacent to target. Make a melee attack with Advantage.
- Dash: Double movement, no other action.
- Disengage: Move away from melee combat. No other combat action this round.
- Regroup: Combine two or more partially depleted units into one (similar specs). Move up to speed to contact. Revise HP and token count for the new unit. Takes initiative slot of the unit that performed the action.
- Split Up: Separate a unit into two. Move some tokens away. Revise HP for each group. New unit takes initiative one less than original. Singular creatures choose which unit to stay with. Can split once per round. Can move before or after splitting.
- Attack - Melee: Engage an adjacent enemy unit (touching sides) or singular creature (adjacent square or inside the unit). Only front-line tokens deal damage against units.
- Attack - Range: Within maximum range, no adjacent enemies. Most ranged weapons (e.g., longbows) fire in 45-degree arcs, allowing all tokens to shoot if one has line of sight. Multiply damage per token by number of attacking tokens, not to exceed twice the defending unit's tokens. Crossbows have flatter trajectories; only tokens with direct line of sight attack.
- Cast a Spell: (See Magic Section)
- Set against Charge: Use unit action (requires reach weapons). Unit maintains defensive status until moved or another action taken. When charged, make an opposed Dexterity save. If the charging foe wins, attack with disadvantage. If the defending unit wins, make a reflex attack with advantage. If repelled, charging unit stays adjacent but cannot attack until next round.
- Form a Phalanx Formation: (Requires shields). Advantage on ranged attacks made against it. Move rate halved (min 1 square). Cannot charge or attack with range weapons. Melee attacks with reach weapons at disadvantage. Protects embedded NPCs/PCs but prevents their attacks. Can still Set against Charge.
D. Bonus Action:
- Change Formation: Rearrange tokens within the unit as desired, provided each token is adjacent to at least one other, no "holes," and no token moves further forward than the current front-most token. Cannot be used to surround a currently engaged opponent.
V. Resolving Combat
A. Damage Calculation:
- Single Creature Damage: Use standard D&D 5e stats.
- Damage per Token: Single creature damage x 10 (at Standard Scale).
B. When a Unit Attacks another Unit:
- Melee: Multiply damage per token by the number of tokens on the front line (adjacent to enemy tokens).
- Range: Multiply damage per token by attacking tokens (not exceeding twice defender's tokens). For crossbows, only tokens with direct line of sight.
C. When a Unit Attacks a Singular Creature:
- A unit can only attack a singular creature not in an enemy unit. Can attack multiple singular creatures up to the number of tokens in the unit (one attack roll per target).
- Melee: Singular creature damage x (number of creatures that can attack). Use D&D 5e rules for surrounding.
- Range: Only tokens with direct line of sight. If Huge+ target, multiply damage per token by attacking tokens. If smaller, divide damage per token by 3.
D. When a Singular Creature Attacks a Unit:
- Damage is applied to the unit's total HP.
E. When a Singular Creature Attacks another Singular Creature:
- Standard D&D 5e combat rules apply. Use a separate mini-battle map (5 ft. per square) if desired.
F. Collateral Damage (Singular Creatures in Units):
- Charge/Melee Attack: Singular creatures receive no damage unless purposefully on the front line. If on the front line, damage as if the unit attacked them.
- Ranged Attacks: If attacker has fewer tokens than target unit, no damage. Otherwise, receive "single creature damage" unless a DC 15 Dexterity save for half damage (or no damage if Dodge action taken).
G. Other Considerations:
- Never Used in Unit Combat: Opportunity attack, Grapple, Help, Hide, Hinder, Knock Down, Dying (units rout, disperse, or surrender).
- Singular creatures follow standard D&D rules for these, and for 0 HP.
H. Taking Damage (Units):
- Damage is spread across the unit. Tokens continue to fight until enough HP is lost to remove a token.
- When tokens are lost, the defender removes them, typically from the back line (representing creatures moving forward to replace fallen ones). Prioritize removing tokens not engaged in melee.
- Unit at 0 HP is vanquished (not necessarily slain).
I. Inter-Unit Actions (Singular Creatures in Units):
- Normally, singular creatures in a unit act as they choose, resolving their actions before the unit acts.
- If enemy creatures enter a unit without friendly singular creatures, the unit attacks them during this phase.
- If friendly singular creatures are present and enemies enter, roll secondary initiative for all singular creatures in the unit. Resolve one round of inter-unit combat.
- The unit's creatures move back to allow inter-unit combat. They do not interfere or attack unless their allies are defeated or if attacked directly.
VI. Morale & Resolution
A. Winning the Combat:
- The battle ends when one side surrenders, or all its units surrender or rout.
B. Morale Check (DC 15 Wisdom):
- Required Conditions:
- Attacked by a ferocious creature (DM's discretion).
- Unit reduced to half its original number of tokens.
- Unit reduced to 1/4 its original number of tokens.
- Only one token remaining (DC 20 Wisdom check to avoid surrender).
- Failure: Unit routs.
C. Rout:
- Effect: Frightened condition. Flees from hostile units.
- Melee Engagement: Opponent can take a reaction to make a melee attack.
- Actions: Cannot take reactions. Can only Dash or escape effects preventing movement.
- Surrender: If cannot flee, drops weapons and surrenders.
- Rally: DC 15 Wisdom check at start of turn. Failure for three consecutive rounds means unit scatters (no longer rallied, removed from combat).
- Singular Creatures: May (but not required to) flee with routed units.
D. Surrender:
- Any unit or singular creature can choose to surrender at the start of its turn. Cannot move or take other actions.
- If accepted, combat ends for those creatures. If attacked, attack is with advantage, and combat continues.
E. Recovering Casualties:
- Unit HP represents fighting capability, not precise casualties.
- At battle's end: Victor recovers 50% of lost Unit HP. Defeated side recovers 25% of lost Unit HP.
- When healed HP equals/exceeds one token's HP, add a token back (represents wounded rejoining). New tokens should not be placed adjacent to enemy tokens.
VII. Magic
Magic functions largely as in standard D&D 5e, with adaptations for units.
A. Spell Ranges:
- Touch Spells: Caster's square must be in contact with target's square.
- Other Ranges: Distance in feet between caster's square and target.
B. Spell Targets:
- Singular Creatures: Affected per standard D&D 5e rules. Singular creatures in a unit cannot be targeted by spells (safe from targeted spells, but affected by AoE), unless the caster is in the same unit.
- Units: Cannot be targeted unless the spell causes HP damage or is an area of effect (AoE) spell.
C. Area of Effect (AoE) Spells on Units:
- Determining Affected Creatures:
- Circular: (Radius in feet / 5)2 x 3 = affected Medium/Small creatures.
- Cone: Circular result / 4.
- Tiny Creatures: Affected number x 4.
- Large Creatures: Affected number / 4.
- Huge Creatures: Affected number / 9.
- Gargantuan+ Creatures: Affected number / 16.
- Always affects at least one creature.
- HP Damage Spells: Calculate total HP damage inflicted on all affected creatures and apply to the entire unit.
- Heal Spells: Calculate total HP healed on all affected creatures and apply to the entire unit. Unit HP (and token count) cannot exceed original amount. When healed HP equals/exceeds one token's HP, add a token back.
- Other Spell Types (Buffs, Hinders, etc.): Calculate total affected creatures in AoE, then divide by 10 (at Standard Scale) to get affected Tokens. If the spell doesn't affect the entire unit, the unaffected tokens perform a "Split Up" action as a reaction, forming a new unit.
- Collateral Damage (Singular Creatures in Units): If an AoE spell affects all unit tokens, singular creatures within must make saving throws or be affected normally.
- Turning Undead: Use AoE rules to determine affected undead/tokens. Affected tokens rout, scatter, and cannot be rallied.
D. Singular Creatures Casting Spells:
- Per standard D&D 5e rules, with unit adaptations noted above.
E. Units Casting Spells (Optional, for Magic-Heavy Settings):
- Conditions:
- Target's saving throw is at disadvantage.
- Every creature in the unit must be capable of casting the same spell at the same level.
- Only one spell (the same spell) can be cast
per round. - Target: One unit or one singular creature. AoE spells can target a PC squad (if not in a unit).
- Line of Sight: Only casting tokens with line of sight to the target square can cast.
- Effect: Even if not all tokens cast, the entire unit loses that spell slot, and other tokens cannot perform other actions.
- Targeting Multiple Tokens: When attacking another unit, each participating token must target a different token in the enemy unit.
- Units Casting AoE Spells: Determine max tokens in casting unit with line of sight/range. Only that number of tokens cast. Multiply determined HP damage or affected tokens by the number of casting tokens.
F. Proportional Saves (Optional Rule):
- Instead of unit saving throws, subtract saving throw bonus from DC, multiply by 5. Result is the percentage of tokens in AoE that failed (min 5%, max 95%). This averages the outcome.
VIII. War Machines
Siege weapons and devices introduce unique strategic elements.
A. General Rules:
- Placed in outlying units, typically at the rear of the army.
- Units and singular creatures can target war machines (even if in a unit) using rules for attacking singular creatures.
- Do damage to units/singular creatures using ranged attack rules for singular creatures.
- Do damage to structures/other siege weapons using rules for creatures attacking creatures.
- Range: Standard ranged combat. Catapults/Trebuchets cannot target closer than half their normal range.
- Size: Space required to operate (e.g., Ballista 5x5 ft. No more than one per square).
- Rate of Fire: Actions crew must expend to fire/reload.
- Crew: Minimum number of crew required.
B. Siege Weapon Units:
- Unit Type: Standard unit with exceptions.
- Composition: Contains one siege weapon (figure placed on a token). Singular creatures can also be embedded.
- Destruction: If siege weapon destroyed, unit makes DC 15 Wisdom check (failure: rout). If not, becomes standard unit.
- Size: Cannot have fewer creatures than min crew. Typically single token.
- Operators: Should be trained (otherwise disadvantage on firing).
- Movement: 15 ft./round, cannot Dash. Cannot load/fire or attack with personal weapons on a round it moves.
- HP: Unit HP separate from siege weapon HP. Can target unit or weapon.
- Actions: Loading/firing counts as unit attack action. Tokens not involved take total defense. Cannot charge.
- Defenses: Can set against a charge (requires enough creatures to circle weapon + min crew). Cannot form phalanx.
- Through Units: Can move through allied units, not enemy units.
C. Siege Towers:
- Unit Type: Standard unit with exceptions.
- Composition: Entire unit (50 Medium/Small creatures, 5 stacked tokens) is contained within the tower.
- Initiative: Disadvantage to initiative.
- Movement: 15 ft. every other round. Tokens cannot attack on rounds tower moves.
- Attacks: Tokens can fire arrows through slits (disadvantage to attack). One token per side, four different targets.
- HP: Unit HP separate from tower HP. Can target unit (at disadvantage) or tower.
- Actions: Cannot charge. Can move through allied units, not enemy units.
- Deployment: If unopposed, can lower drawbridge onto a wall on the round after entering adjacent square. Tokens exit at 10 creatures (1 token) per round. Surrounding units use tower as covered stairway at same rate.
- Once Deployed: Becomes a standard unit.
D. Battering Rams:
- Unit Type: Formed from creatures leaving a forward unit. Occupies one square. Initiative one less than original unit.
- Composition: Only enough creatures to carry/swing the ram.
- Actions: Two actions: move at standard rate or attack adjacent structure with ram.
- Defense: Cannot carry shields, no Dexterity bonus to AC.
IX. DM Tips for Epic Encounters
- Focus on Narrative: Use descriptive language to convey the chaos and scale. Don't get bogged down in every tiny detail.
- Break Down the Battle: Divide the overall conflict into smaller, thematic encounters or phases.
- Character-Centric Objectives: Give PCs specific, impactful missions (sabotage, target elimination, defense of key points). Treat them as a "special forces" unit.
- Streamline Side Actions: For events not directly involving the PCs, resolve them narratively rather than rolling out full combat. "While your squad is taking down the commander, the left flank of the goblin horde begins to crumble under the elven archers' barrage."
- Player Agency: Allow players to issue commands to allied units as a bonus action (within 60 ft.), influencing the battle's flow.
- Morale is Key: Leverage morale checks to add tension and the possibility of routing forces, creating dynamic shifts in the battle.
- Visual Aids: Utilize the battle grid, tokens, and miniatures.
- Embrace the Chaos: Large battles are inherently chaotic. Don't strive for perfect simulation, but for exciting and impactful gameplay.
This system aims to provide a clear framework for running massive D&D battles. It borrows heavily from the structured approach of "D&D Wars" for unit mechanics and the narrative focus of "Running Large Battles" for player engagement. Feel free to modify and adapt these rules to best suit your campaign and playstyle!
