AD&D1e: Hex on up

Gear needed for this article:

• snacks
• AD&D1e Dungeon Master's Guide
• AD&D1e Monster Manual
• Polyhedral dice
• Hex paper and notepad, or
• Laptop with internet connection

Commonly GM guides will tell you to draw a world, then a continent, put in mountain ranges and so on. This "top-down" approach (as detailed very well by Bat in the Attic) is lots of fun, because we all like to draw big maps. But it's less than useful for running a game, because you invariably get caught up in minor details that'll never see the light of play. On the principle of "the teacher only needs to be one chapter ahead of the students in the textbook," the GM only has to be a few hexes ahead of the players in the game world. 

You only need a small scale. If you have a location service on your mobile phone you can review it and see that most of us only have three or four places we always go. Most medieval villagers never went more than twenty miles - a day's hard walk - from their homes in their entire lives. There's a reason people talked about "join the army/navy, see the world!" because for most people, that was the only way an Englishman would ever see India, or a Senegalese would ever see France. Adventurers of course are simply a small army with no proper leadership. 

So you start small and build up and around it. The AD&D1e Dungeon Master's Guide is of course the foundation of all gaming wisdom, and it offers us some guidance on this. In the years since, people have developed many useful charts, and since the dice are always right, we just roll things up. 

This is the procedure. I include the websites first. As always, don't worry if the results are weird - "How can the knight be lawful evil and his wife chaotic good?" because the dice are always right. Roll it up now, make sense of it later. 

The scale used will be one mile hexes. This is the recommendation of the DMG p173 as pictured above, and is actually a decent scale. Look at a map of where you live, a mile across contains quite a lot of people and scenery. A medieval fantasy world will be less populated by people, but - like a wilderness area today - have more animals. 

1. Hextml. Begin with a blank hex map. I use hex paper and a notebook, but some people prefer using computers, and this is also useful if you're gaming online with distant people. In either case you need three sections for each hex: Text (its name or number), Secret Notes (what the DM knows, eg dungeon maps) and Player Notes (what is public knowledge about this hex). 
2. Pick a hex and choose some starting terrain. The nearby terrain is likely to be more like this, so choose what you'd like to see more of - grassy plains, hill, forest, mountain, desert or whatever. Choose too the local climate - arctic, sub-arctic, temperate, sub-tropical or tropical. This is important later when determining what lives in the area neighbouring the village. 
3. Starting village. Now create the starting village. S John Ross wrote a useful article called Medieval Demographics Made Easy, which tells us how many blacksmiths or chandlers we're likely to see in a place. There are many online generators for this, we recommend Donjon, as for everything else.
1. Start small! Less than 300 people means the place is small enough to need adventurers, and the things the party needs won't be available - they'll have to adventure to find them! Sketch the layout of the buildings, being logical - for example, since urine is used to cure leather, the tanner is not likely to be right next to the village well. 
2. Give it a map. You can draw it yourself, or use a random generator like this one. 
3. DMG pp100-102. Detail this village's significant NPCs - the nobles, the officers, and the artisans. They don't need stats, but roll up their personalities, and consider how they relate to each-other. 
4. DMG p.173. Terrain. Each hex is 1-6 miles across. Starting with the northern hex and working clockwise, roll for the terrain adjacent to the starting village hex. Do this for all six hexes. I prefer a one-mile hex, others have argued for a six-mile hex. Do as you see fit. In either case, consider that just as characters within a dungeon will move at (for example) 60 foot per round when simply walking and 60 foot per turn when searching for secret doors, traps etc, so too will characters searching a wilderness hex for signs of monsters take a long time to traverse a relatively short distance. As an exercise, one day go into a national park and search a 1 mile across area for signs of large wildlife. 
5. Inhabitation. Check if there is a normal settlement or ruins. Note that there is only a 14% chance, with a 2% chance of ruins - otherwise "uninhabited" is the result. But -
6. DMG pp183-189. Predators. We assume there are endless numbers of ants, dogs, deer and so on in any hex, what we are interested in is the things which might kill, capture or eat you - the predators! One kind per hex. Normally DMs roll for the party to encounter wandering monsters. But note: this is not a roll to see whether monsters exist in the area, but whether the party encounters them. I haven't seen a fireman all week - but the fire station is about five hundred yards from my home, I'm pretty sure they didn't all close up and go home. But if a party thoroughly explores a hex, they will find those monsters and sign of them. You can't have a dragon flying around without cattle and sheep disappearing, or 120 goblins marching about without leaving muddy tracks or manure by the side of the road. 
1. Roll for the appropriate monster, and consulting the AD&D1e Monster Manual, check the Number Appearing. Note especially that some monsters will have different Hit Dice etc based on their numbers, such as having a chief or shaman. 
2. % in Lair: with wandering monsters as the party travels across the wilderness, this is normally the chance that they'll stumble across their lair. With the Hex Up method, this is taken as the chance that the monsters have a lair in this hex - they may simply be travelling through, scouting, raiding, looking for food and so on. 
3. Use the AD&D1e Treasure Generator: noting the Treasure Types of the monsters in the MM, roll for any treasure they have. Note that monsters without a lair will have only individual treasure, and of course the monsters may be encountered outside their lair, and even if defeated, the party may have to find their lair later. 
4. Detail the disposition of the monsters, and the layout of their lair, if any, and where they have their treasure stored, if any. Note especially any magical treasure, since intelligent monsters will be using this if they can! The goblin chief will most definitely use that +3 morning star, and he might chug back those Potions of Healing before the party can smack him down. 
5. If they have a Lair, you can generate it randomly, simply putting the main monsters in wherever you see fit, or else design it in detail with this mapping page. 
7. Roads and rivers. Having done all this for the starting and six surrounding hexes, you now have six hexes. Go one level out and detail the other twelve hexes surrounding those. Place roads and rivers where seems appropriate - there will be roads between any current and former places of human inhabitation, even if the "road" is just the place grass won't grow because people keep walking over it. Rivers will tend to flow from mountains and hills down towards the sea, lakes or marshes. 
8. You will now have the starting village and 18 hexes of places to explore and monsters to slay, bargain with, or set against each-other. Perhaps those 80 neutral-alignment bandits could be persuaded to deal with the 12 ogres? Perhaps the 12 ogres could be persuaded to deal with the 120 goblins? And so on. This should be enough to keep a party of 1st level adventurers busy for at least half a dozen sessions, and give them a few levels of experience. 

Edit: 2022-01-26: I do a regular livestream with DungeonDelver, and a recent one showed how to create a game world - from the hex on up. You can watch it to see this in action and get some more ideas; the first half-hour is chit-chat, and after two hours I'm off and they game, but from 30'-2hr it's hex crawling.