Reddit reviews Stronghold Builder's Guidebook (Dungeons & Dragons d20 3.0 Fantasy Roleplaying)

This would appear to be relevant to your interests, but you need the DnD insider subscription thing. I don't have it, so I can't tell you how good/bad it is.

The Stronghold Builder's Guidebook could be helpful, but it's for 3.0, not 4e. Could be useful as guidelines/inspiration though.

I think it would work better to keep the castle related stuff plot-driven, as 4e's mechanics don't really mesh well with the kind of gameplay that having a castle implies.

Without knowing the system you are using, I'll just go with the ones I use (3.5 & Pathfinder).

The Stronghold Builder's Guide is a great reasource that focuses on castles, buildings, and how to incorporate it into a campaign. I have a couple of characters that used this rulebook to build a massive stronghold in a lawless area of a kingdom they protect. One character built a tree suspended mansion with staff to retreat to. Another has a family bakery and tavern in a small town.

Pathfinder's PRD on Kingdoms and War has a good set of rules on dealing with full on kingdom building placing the PC's in positions such as king or queen, minister of war, etc. I haven't got my players to this point yet and I intend on using it when their current set of characters gets to retirement level.

It sounds all very nice to inherit a castle, but have you thought about the maintenance? A castle costs like a goddamn fortune. Just the maintenance is something between 1 and 2% of the total stronghold cost (see [1] page 90).

But you didn't think about that, did you? Nooooooooo. You frikkin' youngsters all go on adventuring, not taking any responsibilities whatsoever.

You've got staff to pay, young man. Like the guards, the cook, the stable hand, a handyman, the groundskeeper, a scullery maid, and so on. And then there's the occasional hire, like a rogue to keep your traps up to snuff, plus a dwarven engineer if the stronghold is partially underground (see [1] page 89).

But you say, I'm not going to pay that! Them peasants gotta pay taxes. Well yeah, captain Obvious. The most obvious way is of course taxing the common people. But they don't pay for nothing. You have to provide good service for them, like taking care of the occasional rampant ogre, hungry wolves, or some weird evil sect that's digging up skeletons in the local church' graveyard. And nowadays the peasants expect to be educated, as well. Gotta pay the local hedge wizard to educate them damned kids.

Of course, if the peasants aren't happy with your services, accidents could happen. Maybe you'll step into a bear trap that someone forgot. Or maybe during hunting whoopsie somehow an arrow came your way! Or maybe you wake up one day stricken blind for one year, because some goddamned Harper thought you needed to be taught a lesson.

The Castle Lord's life ain't easy, son.

[1] Stronghold Builder's Guidebook http://amzn.com/0786926554

The Stronghold Builder's Guide was a thing back in the day. You can pick it up pretty cheap now.

I am late to the game here but.

https://www.amazon.com/Stronghold-Builders-Guidebook-Dungeons-Roleplaying/dp/0786926554

There was a 2nd edition version of this book as well. Building settlements has been part of D&D for ages. Surviving after the fall of civilization will require some sort of shelter.

The actual mechanics of this can be debated, but having an option where you can put down roots and do more than just survive is a nice and good thing.

you could try This.

> Goblins

Actually, I think they'd be more likely to strike as soon as the party makes themselves comfortable - as in, they settle down for the night - after clearing a large infestation.

> Recruiting soldiers at different cities

1. Don't forget to implement Charisma checks (Diplomacy) for recruiting soldiers. A well-spoken, seemingly good leader will be more efficient at recruiting than a completely uncharismatic Wizard.
   
   
2. Keep in mind you can hire a dozen spearmen at any village for a barrel of mead and a gold coin, but given enough time you'll train them up to elite levels. Provided they don't skip fortress (which seems realistic). Recruiting experienced soldiers at cities will save time, but not gold in that case.
   
   And, IIRC, pay for a trained soldier is between 1 silver and 1 gold coin (1 gp = 10 sp)... at least in 3.5.
   
   ----------------
   
   No idea what edition are you playing, but Stronghold Builder's Guide has plenty of material not restricted by editions. Book of Challenges also has a pile on info for making in-built castle and dungeon protection mechanisms (read: traps).
   
   Finally, take a look at Stirling Castle, Scotland. I came across it fairly recently, been drooling ever since. It looks amazing. Only needs some adjustments for a fantasy setting - for example, protection against flying enemies.
   
   Happy DMing! :)

So this isn't Pathfinder canon, but there is a softcover book called Stronghold Builder's Guidebook. The book was released for D&D 3.0 and covers the costs of building a stronghold that can be as small as a 1 bedroom hovel or as large as a castle.

I bought this book that uses 3.5 rules and it has everything.

https://www.amazon.com/Stronghold-Builders-Guidebook-Dungeons-Roleplaying/dp/0786926554