d66 Reasons Why the Castle is Totally Deserted

My most recent foray into using the AD&D DMG to stock a hex map sparked some discussion about the frequency of "totally deserted" castles.

According to the DMG's inhabitation table, each "space" in the wilderness (1 mile according to Gygax, 6 miles according to conventional wisdom - or not) has a 3% chance of containing a "castle" (more accurately described as a fortress or stronghold):

Of those castles, 35% are small, 45% are medium, and 20% are large. In turn, 45% of small castles, 30% of medium castles, and 15% of large castles are "totally deserted":

If my math is right, that means that 32.25% of castles are totally deserted.

What does that mean? Well:

How could this be? We had a discussion about it over on the Prismatic Wasteland Discord. A variety of possibilities were proposed (some of my commentary in parentheses):

• The castle was just invaded and the invaders haven't yet brought their full force over. (But surely the invaders would have left some sort of garrison there to hold the location while they moved their full forces in. Castle Table II already accounts for the possibility of human inhabitation. The notes for that table are clear that the castle "appears empty", so this is an unlikely explanation.)
• The castle is so ruined/old so as to be functionally worthless as a castle unless its completely rebuilt. It's so bad, even monsters won't live there. Now that's saying something!
• The castle is logistically difficult to occupy or supply.
• The castle is no longer strategically significant. 
• The castle is/contains a dungeon. (But again, the notes on Castle Table II state that the castle appears empty upon close inspection. Dungeons contain monsters, tricks, traps, and treasure, so I would not say a castle which contains a dungeon is empty unless the dungeon is empty as well, which brings us back to: why?)
• The castle is inhabited/contains a dungeon, but the inhabitants/dungeon are hidden. (The notes on Castle Table II say only that the castle appears empty.)
• The castle is cursed/plagued.
• The castle is protected by some regional taboo against entering it.
• The castle is intended, from a metagame perspective, to be reoccupied and rebuilt by enterprising player characters.
• Gygax simply liked the idea (perhaps inspired by Middle Earth) of a troubled land where even grand castles lie in ruin due to the insidious influence of Chaos/Evil/Shadow.

Those last two points are key, and I agree with both. The implied setting of Gygax's D&D is post-collapse. This may have simply been Gygax's aesthetic preference, make of it what you will. But that aesthetic preference is then awfully convenient for player characters, most of whom are expected to eventually command a castle - usually by clearing an area of monsters and then building one there. Wouldn't it be convenient if there was some totally deserted castle already built for them (albeit "in disrepair")?

If this was the intention, it also makes sense that deserted castles are mostly small constructions - the player character can capitalize on the convenience of an existing castle, but if they want a big castle, they'll (probably) have to build it themselves (there is only a .09% chance per hex of finding a deserted large castle - meaning there is one roughly every thousand hexes - compared to a .4725% chance of deserted small castle and a .405% chance of a deserted medium castle). 

It's also important not to shut out what the procedure is trying to say. There are castles all over the place (approximately one every 33 miles, if the suggested 1 mile scale is used - meaning you usually can't walk a day and a half without coming upon one). One-third of them are totally deserted. Every castle is constantly under threat of ruination so great that even monsters won't inhabit them. The fact that larger castles are less likely to meet this fate suggests that only the greatest fortifications are likely to withstand this threat, whatever its nature may be.

Perhaps I'm reading too much into it, but when I look at those numbers I think, "Damn, if I'm going to survive in this world, I have to build a castle. And it better be a big one!"

But what exactly am I trying to endure? What happened in this world? What is currently happening to its castles that causes them to become deserted?

WHY IS THE CASTLE TOTALLY DESERTED? (d66)

(11) Ambient Magic. Whatever powerful magic brought the castle to ruin lingers to this day.

(12) Antipathy. The castle is enchanted so as to psychically repel all who would occupy it.

(13) Barren Lands. The land around the castle is not suitable for sustaining crops.

(14) Barrier. The castle is ensconced within a field of force that is yet to be dispelled. 

(15) Conjured Garrison. The castle appears empty, but is defended by magically conjured creatures should anyone attempt to occupy it.

(16) Cursed. Anyone who tries to live there suffers calamity.

(21) Displaced. The castle is out of sync with time or the known dimension, appearing and disappearing at random intervals. It just showed up again. The people who once ruled it didn't come with it.  

(22) Divine Mandate. The castle is forbidden by a deity, who punishes those who disobey it.

(23) Dry. The castle's wells have dried up, and it's too difficult to bring it water.

(24) Forsaken. An atrocity was committed in the castle's past. None inhabit it due to its reputation.

(25) Gateway. All who enter the castle are transported to another world or time.

(26) Haunted. The spirits of the dead haunt the castle, driving out occupants or else driving them mad.

(31) Hidden Dungeon. The castle contains a dungeon, but it is hidden away so that the castle appears empty.

(32) Illusion. The castle only appears empty. A powerful illusion hides its true nature and inhabitants.

(33) Inaccessible. The castle is built in a place which is difficult to reach, and recent circumstances (snow, overgrowth, flooding, etc.) have eliminated the most well-known paths.

(34) Invisible Foe. The castle is occupied, but its inhabitants are invisible or otherwise difficult to find.

(35) Irradiated. Ancient civilizations dropped weapons of mass magical destruction on the castle. Those who attempt to occupy it suffer sickness and mutations.

(36) Irrelevant. The political landscape has rendered the castle's original purpose insignificant, and none wish to occupy or maintain it.

(41) Lost to Time. The castle's original inhabitants perished so long ago that all record of its location has been lost.

(42) Mimic. The castle is no castle - it eats anyone who occupies it!

(43) No fortifications remain. The masonry has crumbled or been melted by dragon fire. It has no defensive value, and to rebuild it would cost almost as much as to build a brand new castle.

(44) Non-Euclidean. The castle's geometry is incomprehensible to human minds, causing those who inhabit it to go mad or become lost forever in its halls.

(45) Omens. The local ruler is awaiting an auspicious omen before reoccupying the stronghold.

(46) Petrification. The castle is populated with lifelike statues. Any who inhabit it are turned to stone at sunrise.

(51) Plague. The inhabitants died of a fast-spreading illness which threatens to infect any who occupy it.

(52) Prophecy. The local ruler is awaiting a Chosen One to come of age before bestowing the castle upon them.

(53) Remote. The castle is too far from civilization to be sustained.

(54) Ruler's Mandate. A local power has forbade anyone from occupying the castle, and frequently sends out patrols to ensure it is so.

(55) Sacred Site. The castle is a location of importance to a powerful religion. It is left unoccupied out of respect.

(56) Storm-Wracked. A change in climate has caused the castle to be constantly assailed by storms, freezing winds, crashing waves, or the like.

(61) Too Cold. It's just too cold there!

(62) Too Hot. It's just too hot there!

(63) Treaty. Two or more competing powers have agreed that none should occupy the castle, lest they risk starting a war.

(64) Unsound. The masonry is unstable and threatening to collapse, and no one has the means to fix it.

(65) Unstable. The castle is built on shifting earth, a sinkhole, an eroding cliffside, or some other dangerous type of terrain.

(66) Vampiric. The castle drains the life of those who occupy it, binding their souls to its halls.

Not all of these entries explain why monsters wouldn't inhabit these castles, but I thought it was more important to answer the question of human desire - after all, these are (mostly) human constructions and represent significant investment on the part of humans. The map as presented at the beginning of a D&D game is only a snapshot of the region at that time. Just because no one occupies a castle now doesn't mean they won't do so later.

There's definitely some overlap here, and not every entry is inspired (I added "too cold"/"too hot" at the end just to get it over with - shoutout Goldilocks fans). The more mundane entries probably fit whatever Gygax's original intention was, while the more fantastic may not. My goal was not to make a perfect table, but merely to demonstrate that there are many factors - both realistic and fantastic - that could result in these locations being abandoned. 

On Discord, we also discussed how having over 30% of castles be deserted is not fun. Hopefully I demonstrated how one can avoid making many of these locations dull. Even if a castle is unoccupied for a totally mundane reason - like a territorial dispute, an inaccessible location, or its sacred status - it shouldn't take much thought to turn that into a compelling scenario filled with intrigue and adventure.