Guide for Dungeon Masters
Build Your Campaign World
From geography to politics to hidden secrets. A practical guide to building D&D world maps that serve your campaign, not just decorate it.
Watch procedural generation build a world in seconds.
Step 1 — Start with Geography
Every world starts with land and water. Before you name a single kingdom, decide where the continents, oceans, mountain ranges, and rivers are. Geography shapes everything else — trade routes follow rivers, cities grow at harbors, wars happen over mountain passes.
Think in broad strokes first:
- A mountain range splitting the map creates two distinct regions with different climates
- A major river flowing from highlands to coast becomes a natural trade corridor
- An archipelago off the coast invites naval adventures and pirate lairs
- A desert to the south means a different culture, different resources, different threats
In Hexer, use the 35 terrain types to paint your geography. Forests, mountains, plains, deserts, oceans, swamps — all free. Place them in natural-looking patterns: forests at the base of mountains, swamps where rivers meet the sea, plains in the rain shadow of mountain ranges.
Step 2 — Use Procedural Generation as a Foundation
Building a world hex by hex takes hours. Hexer's procedural generator creates a realistic starting point in seconds — coastlines, elevation, biome-aware terrain, river systems, and settlement placement.
Choose a template:
Island
A landmass surrounded by ocean. Good for isolated campaign settings where the party can't just walk to the next continent.
Continent
A large landmass with varied terrain. Coastlines, interior mountains, forests, plains, and deserts. Good for open-world campaigns.
Caves
An Underdark cavern network. Tunnels, chambers, underground lakes, and fungal forests. Requires Pro for Underdark layers.
After generation, hand-edit to match your vision. Move the mountain range, add an enchanted forest, delete a river that doesn't fit. The generator gives you nature; you add narrative.
Try painting terrain — pick a type and drag across hexes.
Step 3 — Place Settlements and Trade Routes
Settlements don't appear randomly. Cities grow where resources meet transportation — river junctions, natural harbors, mountain passes, fertile plains. Place your towns and cities where they make geographic sense.
Use Hexer's 18 hex features to mark settlements, dungeons, sacred sites, ruins, and more. Then connect them with paths:
- Major roads between large cities — well-traveled, safer, faster movement
- Trade routes connecting resource-producing regions to markets
- Trails through wilderness — less safe, used by rangers and smugglers
- Rivers as natural highways — boats can carry goods faster than carts
Think about what each settlement exports and imports. A mining town in the mountains trades ore for grain from the plains. A port city imports exotic goods from across the sea. These trade relationships drive adventure hooks — bandits on the trade road, a blockade at the harbor, a drought threatening the grain supply.
Step 4 — Define Political Regions
Geography creates the land. Regions create the story. Draw named, colored regions to represent kingdoms, tribal territories, disputed zones, and wild lands.
Good regions create tension:
- Two kingdoms claiming the same fertile valley
- A free city surrounded by a hostile empire
- Tribal lands with no central authority — each hex might have a different leader
- A blighted zone spreading outward from a corrupted ruin
In Hexer, regions are independent of terrain — a single "Elven Dominion" region can span forests, rivers, and hills. Color-code them so the political landscape is visible at a glance. Region borders follow natural features: rivers as borders, mountain ranges as barriers, coastlines as limits.
Step 5 — Add Secrets and DM Notes
A world map without secrets is just a geography lesson. The best campaign worlds have layers of hidden content — dungeons, prophecies, political conspiracies, and ancient ruins that players discover through play.
Use Hexer's DM notes to attach campaign hooks to hexes:
- Encounter: "Dragon turtle nesting ground. Approaches ships within 2 hexes."
- Secret: "Hidden entrance to the Underdark beneath the waterfall. DC 18 Perception."
- Landmark: "The Weeping Colossus — a 200-foot statue half-sunk in the swamp. Who built it?"
- Quest hook: "The duke's missing daughter was last seen heading into the Thornwood."
Mark notes as DM-only so they stay hidden when you share the map with players. They see the terrain and paths; you see the secrets underneath.
Step 6 — Scale Considerations
The hex scale you choose changes how your world feels at the table:
6-mile hexes (campaign scale)
The D&D standard. A party on foot covers 3-4 hexes per day. Each hex is large enough for a village, a dungeon, or a notable landmark. A 20x15 map covers roughly 120x90 miles — enough for an entire campaign region. This is the most popular scale for hexcrawl play.
24-mile hexes (regional scale)
Good for zoomed-out continent maps where you want to show kingdoms and major geography. Each hex might contain several points of interest. Travel between major cities takes days, not hours. Best used alongside a 6-mile detailed map for the area where play actually happens.
1-mile hexes (tactical scale)
Close-up detail for a single valley, city surroundings, or battlefield. Good for focused scenarios where terrain matters hex by hex. A 20x15 map covers just 20x15 miles — one day's travel at most.
Start with a 6-mile hex campaign map. It's the most versatile scale and matches the movement rules in most tabletop RPGs. Hexer's free tier gives you a 20x15 grid — plenty for a full campaign. Pro extends up to 200x200 for massive worlds.
Start Building Your World
Hexer gives you everything you need — 35 terrain types, 18 hex features, procedural generation, regions, DM notes, and live sharing. Free to start, no account required.
Frequently Asked Questions
What hex scale should I use for a D&D world map?
The D&D standard is 6 miles per hex. At this scale, a party on foot covers 3-4 hexes per day, making travel feel meaningful without being tedious. For a continent-scale overview, some DMs use 24-mile hexes (each containing four 6-mile hexes). Hexer works at any scale — just decide what each hex represents and note it in your map settings.
How big should a campaign world map be?
A 20x15 hex map at 6-mile scale covers about 120x90 miles — enough for a full campaign region. Most campaigns only explore a fraction of a larger world, so start small and expand. Hexer's free tier supports maps up to 20x15. Pro supports up to 200x200 for continent-scale worlds.
Should I use procedural generation or build by hand?
Both. Hexer's procedural generator creates a realistic foundation — coastlines, mountain ranges, forests, rivers, and settlements — in seconds. Then hand-edit to match your campaign vision: move that mountain range, add an enchanted forest, place a dungeon entrance. Generation gives you natural-looking geography; editing gives you narrative purpose.
Can I run a world-building session with players?
Yes. Share a live link with your players and build the world collaboratively. Everyone sees terrain changes in real time. Hexer's live sharing makes collaborative world-building sessions easy — no file passing needed. After the session, add DM-only notes and secrets that players won't see.
What's the difference between regions and terrain?
Terrain defines what the land is — forest, mountain, desert, ocean. Regions define who controls it or what it's called — the Elven Dominion, the Blighted Wastes, the Free Cities. In Hexer, regions are named, colored overlays that span multiple hexes. They're independent of terrain, so a single region can contain forests, plains, and mountains.