Fifth Edition Rules
Mass Combat and Formations for D&D 5e
Battlefield scale, Formations, sections, Suppression, artillery Batteries, and fog of war.
When a fight grows past the point where every soldier deserves an initiative slot, switch scales. The Battlefield map resolves the local tactical engagement, not the entire war, and a Formation is a coherent military body acting as one Battlefield entity with AC, HP, Speed, Facing, one Action, one Reaction, and a Formation Bonus.
When coherence ends, zoom back to Personal Scale for the survivors who matter. Individual musketry stays on the firearms page.
Compatible with D&D 5e and D&D 5.5e.
Two mechanical scales
| Scale | Typical Grid | Handles |
|---|---|---|
| Personal Scale | 5-foot spaces | PCs, NPCs, every creature, firearm attacks, Volley Fire, boarding, rooms, streets |
| Battlefield Scale | 10-yard spaces | Formations, cavalry Formations, Batteries, ships, fortification positions |
For local land combat, 1 Battlefield square equals 10 yards, or 30 feet.
Sections and HP
A standard infantry Line begins as three 10-yard frontage sections, approximately 30 yards of effective frontage. Quality changes HP and nothing else.
| Quality | HP per Section | Three-Section Line |
|---|---|---|
| Green | 10 | 30 HP |
| Veteran | 20 | 60 HP |
| Elite | 30 | 90 HP |
Veteran example: 60 HP = 3 sections; 38 HP = 2 sections; 19 HP = 1 section; 0 HP = the Formation breaks.
Formation Bonus and AC
All Formations use a fixed +2 Formation Bonus for Battlefield attack rolls and relevant Formation saves. Quality does not change AC. Square does not change AC.
| Situation | AC |
|---|---|
| Poorly ordered troops or militia in open ground | 10 |
| Formed troops in open ground | 12 |
| Meaningful cover | 15 |
| Entrenched | 17 |
Movement and Suppression
| Formation / Posture | Speed |
|---|---|
| Line | 20 yd / 2 squares |
| Column | 30 yd / 3 squares |
| Cavalry | 50 yd / 5 squares |
| Square | 0 |
A Battlefield turn is a coordinated tactical exchange rather than a literal six-second infantry walking interval. Suppression is separate from HP: a Suppressed Formation has half Speed and Disadvantage on attacks until the end of its next turn.
Formation fire and close combat
Once troops are represented as a Battlefield Formation, stop counting individual shooters. A Formation Ranged Attack uses the fixed +2 Formation Bonus. A section engaged in melee cannot contribute its firearm die to a ranged Unit Attack. If every surviving section is engaged, the Formation cannot make a firearm Ranged Attack.
| Formation | Effective Range | Long Range | Damage |
|---|---|---|---|
| Smoothbore Infantry | 100 yd / 10 squares | 200 yd / 20 squares | 1d10 per surviving unengaged section |
| Rifle Infantry | 300 yd / 30 squares | 600 yd / 60 squares | 1d8 per surviving unengaged section |
Long-range attacks have Disadvantage.
| Formation | Melee Damage |
|---|---|
| Smoothbore Infantry with Bayonets | 1d8 per section in contact |
| Rifle Infantry / Light Infantry | 1d6 per section in contact |
| Cavalry | 1d10 per section in contact |
Cavalry attacks with Advantage when the target is Suppressed, has lost one or more sections, is broken, or is fleeing. Square counts as steady, presents Front on every side, and denies flanking. Charging alone grants no Advantage.
Artillery Batteries
Artillery controls areas through reach, observation, and geometry. A gun attacks a target. A Battery attacks an area. A prepared Battery is AC 15, HP 30; at 0 HP it can no longer function coherently.
| Battery | Battlefield Damage |
|---|---|
| Light | 6d10 |
| Field | 8d12 |
| Heavy / Siege | 12d12 |
| Battery | Personal DEX Save | Damage on Failure |
|---|---|---|
| Light | DC 13 | 3d10 |
| Field | DC 14 | 4d12 |
| Heavy / Siege | DC 15 | 6d12 |
Success halves damage. These values represent blast, splinters, debris, and near impacts. A direct heavy-artillery hit is Catastrophic Force. Artillery ranges are authoritative in feet: 30 ft = 10 yd = 1 Battlefield square, and the full range table is in the complete conversion.
Fog of war
| Information | Meaning |
|---|---|
| Visible | Directly perceived. |
| Inferred | Reasonably concluded from evidence. |
| Reported | Received through scouts, observers, signals, or allies. |
| False | Mistaken, forged, misunderstood, or deliberately misleading. |
| Hidden | Actually happening outside the characters’ present knowledge. |