dungeon construction: character

It's rare for a dungeon to spring new-formed from the ground like Athena from the brow of Zeus; so there are questions that must be answered before you are accused of just throwing these things together. This need not be a laborious process and can furnish some additional versimilitude to your game which makes for easier suspension of disbelief.

Purpose - Why is it here? There are a number of reasons to dig out an underground tunnel complex and populate it:

1. Bolthole - Somewhere to go until the heat dies down. If you outrage the locals or if they've offended you, it is prudent to travel somewhere safer. You need fresh air and water, stocks of food, a place to rest and other supplies (spare weapons) as well as a spare exit in case someone tries to flush you out by frontal assault.
   
2. City - When you're dealing in epic scale (can you say mega-dungeon?) the presence of an underground city makes the grade. In the real world, places like Derinyuku or Kaymakli attract travellers and explorers; why shouldn't your underground cities do the same; they can offer things which most above-ground cities may not.
   
3. Deathtrap - A method of execution by those who'd rather think of other things; while it is lamented as singularly lazy by more ambitious evil overlord-types, there are times when a well-stocked deathtrap provides hours of amusement. Many death-traps are used to keep inconvenient truths (like the original minotaur of Crete) out of sight and mind.
   
4. Dungeon - The classic prison; including oubliettes for those you never want to hear from again, well-stocked torture chambers and guardians. Some of these places are designed to bring pain to their occupants, others merely to contain them until more permanent methods can be applied.
   
5. Fortress -When you have a number of violent races hiding underground, wars are real; the appearance of an underground fortress may be prudent if your opponent has aerial superiority. There may be bolt holes, redoubts, empty tunnels and heavy doors to contain explosions as well as low-maintenance traps.
   
6. Lair - Like a bolt-hole but longer term thinking is required. Not quite the size of a fortress this is suited to both civilised and primitive monsters. Sleeping quarters, kitchens and other home comforts must be considered as well as an emergency exit or two. If the lair is placed here by an architect then these may be less than ideal.
   
7. Mine -Another classic, though denizens must beware of digging too greedily and too deep; the mine may still be active, have an owner, have ownership deeds lost deep within it's depths or may even be played out. Mines often have extensive tunnels radiating from a central shaft or spoke. Cave-ins, gas pockets and avarice are all perils.
   
8. Proving Ground - The purpose-built proving ground is popular among secret societies (including such fun types as assassins, aspirant clerics and wizards). Here the initiate may pit their wits against traps designed to test their wits and mettle as well as monsters that may make your life interesting as foes, obstacles or dangerous allies of convenience.
9. Temple - Usually the literal incarnation of an underground religion, this construction is usually done by the faithful. As such, iconography is usually visible and may provide motifs for builders to place secret doors and traps so that only the faithful may gain admittance beyond a particular point.
   
10. Tomb - Where the dead lie in wait. Grave robbing being a profession of choice for some so-called adventurers, there are cunning traps (of impressive lethality), false tombs and guardians (usually the walking dead) in place to protect the bones and grave goods of the patrons of this establishment. Add curses, magics and other hindrances to taste.
    
11. Vault - A place to keep things secret and safe. Usually this implies some kind of treasure and guardians (including traps) to go with it. The destructiveness of these traps is often tempered by the knowledge that at some point what you've kept safe may need to be retrieved. Just look at any Indiana Jones movie to see what this kind of thing can entail.

Re-purposed? - What does it do now? Quite a number of places find themselves repurposed. Given the number of creatures that burrow and tunnel or prefer to stay out of the sun is it surprising that many of the above reasons are combined? Reasons for repurposing include:

1. Abandonment - This may range from a newer, shinier complex being found (and is there a tunnel or was the journey overland?) to the need for the place being eliminated (lairs that have been cleaned out by adventurers for example)
2. Disaster - A disaster can change the very nature of the dungeon. Mines become tombs through earthquakes, cities are flooded and become proving ground for warrior and beast alike. The nature of the catastrophe informs changes to both structure and occupants.
   
3. New construction - Expansion is another possibility. Lairs can become over-crowded, tombs need more sarcophagi or the complex gains additional functions (a mine needs a dungeon for some of it's more feisty workers)

Intent - What do you want the players to experience while they are here? Not only can you play with the characters, you can also play with their players as well.

1. Horror - Tombs, deathtraps and dungeons provide an element of horror.
   
2. Promise of wealth - Mines and vaults promise wealth - though not without peril!
   
3. Challenge - Proving grounds and temples are a challenge to adventure and test of worth; a classic dungeon was The Assassin's Run that apprentice assassins would have to best.
4. Exploration - Boltholes and lairs are areas to trespass upon while fortresses and cities may offer the same or opportunities for trade with those who need it.
5. Refuge - A bolthole, fortress or city may also provide shelter for a brief time and a friendly temple can supply sanctuary, lore or healing if it's needed.