Saturday, December 6, 2008

Fantasy Random Terrain Generation

An off-the-cuff terrain generation system. Not tested, but food for thought. Feel free to suggest changes.

1) Start with a 36 x36 hex campaign map with minimal detail. Divide that into 6 x 6 hex areas we'll call subsectors.
2) First rough in any sea coasts, large mountain ranges or other pre-defined features.
3) Roll on the following table to fill in additional general features.

% dice Roads or Water
01-10 No Road or Water
11-15 Major Road
16-20 Underground Cave/Sinkhole
21-60 River/Stream
60-65 Drover's or Hunter's Paths
65-79 Marsh
80-84 Badlands or broken lands
85-95 Road & Stream
96-00 Road & Marsh

1d4 Direction
1 N-S or S-N
2 E-W or W-E
3 NW-SE or SE-NW
4 NE-SW or SW-NE

NOTE: The roads and streams should be linked up with adjacent subsectors, so GM discretion in marking the map is required.

4) Roll for the presence of settlements in the subsector. Place as you prefer.

% dice Typical Settlements
01-15 None
16-45 1 Village
46-65 2 Villages
66-80 1 Town
81-00 1 Village, 1 Town
95-00 1 City

Note: If you prefer, assess a 5-10% chance the settlement is in fact, ruined, uninhabited or serving as a lair.

5) Roll to determine if there are any special sites.

Wilderness - 1d4 rolls per subsector
Civilized - 1d6 rolls per subsector

% dice Special Sites
01-65 None
66-75 Lair
01-25 Subterranean Dungeon/Caverns
26-00 Surface Encampment/Settlement
76-80 Fortification (Tower/Castle)
01-50 Subterranean Dungeon
51-85 Surface Fort/Castle
86-00 Aerial/Undersea Structure
81-85 Shrine or Sacred Site
01-25 Druidic Circle/Leyline/Sacred Grove
26-46 School or Monastery
47-00 Temple or Shrine
85-86 Inn/Tavern/Caravanserai/Oasis
87-93 School or Monastery or Training Grounds
01-25 School
26-46 Monastery
47-00 Training Grounds
94-99 Tomb or Cemetary
00 Extra-Planar Gate or Portal

6) Locate or place the special sites and settlements you have just generated for the section. As each subsector is 6x6, roll 1d6 for both x and y coordinates. Again, you should exercise discretion or forego the random placement altogether.

7) Check for major inhabitants of the subsector. Attach them to generated settlements/lairs at your discretion

1d6 Habitation Status
1-2 Inhabited (roll below)
3-6 Uninhabited

% dice Inhabitants
01-34 Humanoids
35-84 Humans
85-95 Demihumans
95-00 Non-human Monsters (roll again below)

% dice Monsters
01-15 Giants
16-20 Inimical (Gith, Mindflayers, etc.)
21-30 Lycanthropes
31-45 Undead
46-60 Giant animals/insects
61-70 Fey
71-80 Aerial/Elemental
81-90 Aquatic creatures
91-00 Prehistoric/Dinosaurs

8) For additional details of any of the above sites, features or groups refer to the JG Wilderlands tables, CDD 4 or the DMG.

Final Note: Start with some random data and then delve deeper. Ideally, you should use this method to fill in areas around your own more detailed, handcrafted sites or to spur your own creativity. The dice are not a replacement for common sense and the tables are limited where you are not.


Jeff Rients said...

Great stuff! I immediately printed out your charts to slip into my campaign folder. You never know when PCs will try to wander off the map.

Aaron W. Thorne said...

The Gamemaster Law book for Rolemsater Standard System has a similar system of random terrain generation, but the starting point was a sea coast hex, as it was intended to be used if the players head off to find "undiscovered country."

BTW, any concept for how many miles, km, etc. a hex should cover?

Telas said...

"The dice are not a replacement for common sense and the tables are limited where you are not."

This sentence alone is worth the price of admission. It should be printed on the front of every RPG book, and the back of most GM's hands.

Neusapae said...

Olá Kellrj. É difícil fazer comentários sem entender muito do assunto. Mas posso dizer que a elaboração do blog esta ótimo.
Depois vou ler com calma ok.
abraços e parabéns.....