Ultima Castle Generator now on itch.io

Continuing my quest to upload one of my games from https://slashie.net to https://itch.io every week, I have published Ultima Castle Generator there, a procgen tool to generate castles like the ones you would find while roaming the Britannian countryside in Ultima V. Play with it online here.

I made this one for fun back in 2016, following a challenge from the procedural generation reddit. The process I did was based on examples, checking the maps from the game in order to dissect their structure. You can still find them here

Empath Abbey, from Ultima V

The generator works in three steps, as described in this blog. An intermediate step subdivides the space into utility rooms, which are then filled based on their utility. The source code can be found here in case you want to play around with it a bit.

The version at itch.io features some simplifications in the UI to make it look simpler and cooler, similar to the great generators by watawatabou. The legacy UI was kept at slashie.net including the intermediate generation steps.

Ultima Castle Map Generator: Day 8

Ok, I think I’m done at least for now… I just can’t get something out of my head once I start, this kind of mini projects hijack my mind and derail me from other things I really should be doing, but I’m ready to give this a rest.


It’s done! You can check it out online at http://slashie.net/ultimacastlegen (images are not preloaded so it may take one or two generated maps for graphics to show up)

You can also check the source code at github (It’s not super beautiful, but it was fun!).

As it stands, it generates a single floor layout of a castle based on the design of the old Ultima games, specially Ultima 5. It goes roughly through 4 phases:

  1. Defining a high level structure of the rooms to be placed.
  2. Splitting the available space into rooms, based on the high level structure.
  3. Assign the rooms a given function.
  4. Fill the rooms with the appropriate furniture and contents, based on its function.

During day 8, I did the following

  • Fill the remaining space after the initial room expansion, to ensure most of the space in the castle is used to place rooms.
  • Build throne room, staff quarters, guest rooms, castle lord quarters, dining rooms, kitchens, libraries and halls, furnishing them with all sort of stuff based on the reference material.
  • Render 14×16 pixels sprites instead of 16×16 (high fidelity)
  • Enhance connection of the central feature with the rest of rooms
  • Clean spaces in front of doors to ensure walk-ability.
  • Add treasure chests with secret doors
  • Remove some room types belonging to other floors (forge, for instance)

There is certain room for improvement, and there’s of course the question of adding the basement and additional floors (and connecting all together!). But from what I see, that would take a bit of time.

Doing this generator was pretty interesting… I learned a couple of new tricks I hope will be useful for other projects in the future.

Have fun!

Ultima Castle Generator: Day 7

Screen Shot 2016-02-01 at 11.47.25 PM

Rooms are now linked together, to do this I explore the rooms recursively, starting from these west and east of the courtyard; I scan the map for nearby rooms on each direction, recording the limit segments and then I pick a random place from the segment to place a door. Then I explore the connected rooms repeating the process, as a result the whole map is connected.


  • Rooms’ minimum size is now bigger, in turn the generator now rejects structures in cascade, in case it’s unable to place or assign the rooms
  • Entrance is now split on an in-castle portion and an outside castle segment.

Next up:

  • Finishing entrances and wall corridors
  • Working on the rest of room builders
  • Add moat and drawbridge
  • Put kitchen next to dining rooms

Ultima Castle Generator, Day 5


There’s not a LOT of advancement today, but I decided to skip some steps and go right into the tile renderer (using just floors and walls, without the room’s contents).

From here I noticed some small inaccuracies to be fixed (Notice for example the differences between the west and east towers in the image above), as well as some stuff to be polished on the rooms generator (like adding a minimum width and height for rooms to prevent 3 tile big rooms from happening).

I also created a simple random terrain generator; that one will have to be completed to add the moat, may be.

Ultima Castle Generator: Day 4


I’ve implemented the following:

  • Beautiful symmetry, basically allowing the castle to be “almost” symmetrical vertically. I love how it ended up, with small changes on each side.
  • Allow specifying rooms to be placed in the north of the castle
  • Allow specifying mandatory rooms south of a given room
  • Allow specifying preference for “big” rooms

Following is still pending for the Room Generator:

  • Allow specifying rooms to be placed next to each other (i.e. put the kitchen next to the dining rooms)

Then I’ll work on the “third level generator” to create the tile map.

If all goes well get ready for some cute screenshots tomorrow.

Ultima Castle Generator: Day 3

Ok, I must confess I’m a bit obsessed over this. I’m sorry, I can’t help it.

Lots of advancements today, here’s a sample of the current results. You can check it out online here


Today I created the RoomsGenerator; it takes the high level castle structure as an input from the CastleStructureGenerator and based on it it generates a set of rooms and places them on the map.

I also created the Canvas Renderer in order to be able to visualize the results in a graphic way, this in turn helped me tweak some size parameters on the structure generator.

Placing the towers, walls, entrances and central feature was not very complex, the challenge was filling the remaining space with rooms…


Since the area to be filled is not rectangular (the main hall and the entrances should not be covered), doing recursive subdivision such as the one I made for the Stygian generator was not going to work; I thought as an option I could generate smaller rectangular areas from the big area and apply subdivision to each, but since the scale was so small (32×32 for the full map, about 13×20 or less for the area to be subdivided), I knew subdivision was going to be troublesome.

In the end I thought on doing something I rarely do: placing rooms by brute force. Initial results were not very good with lots of unwanted empty space. I was about to explore other options…


…but then, I figured I could make the rooms grow to fill the empty space! 🙂 As a result architecture looks a bit more “organic” than the one generated by subdivision, with less “long lines”, which is good for small maps like this one.

I’m pretty happy with the current results, following are the next steps:

  • Enhancing the room generator to have in consideration what rooms should be placed next to each other
  • Creating the third level generator which actually renders the rooms into tiles and places all decoration and stuff.
  • Connections between rooms will be added by the third level generator (that should suffice for the scope of the generator).

Ultima Castle Generator – Day 2

Advanced a bit more in the Ultima Castle Generator for the ProceduralGeneration reddit monthly challenge # 2.

The generator now generates a high level structure, based on the rules I derived from observation of the maps.

For now, and hoping to finish in time for the challenge, only the first floor of the castle will be generated.

You can check the source code or play around with the generator online.

Next step is going one level further to subdivide the map into areas based on the generated structure.

Here is an example result:

  "general": {
    "size": "big"
  "surroundings": {
    "hasMoat": true
  "towers": {
    "size": 5,
    "crossWindows": false,
    "circle": false,
    "verticalConnections": false,
    "horizontalConnections": "bottom",
    "connectionCorridors": {
      "type": "halls",
      "hallDecoration": {
        "torches": true,
        "plants": true,
        "columns": false,
        "fountains": false
      "hallWidth": 3
  "central": {
    "type": "mainHall",
    "hasSpecialFloor": true,
    "centralFeature": "fountain",
    "hasFireplace": true,
    "width": 15,
    "height": 14,
    "shape": "cross"
  "entrances": {
    "northExit": {
      "hasFloor": false,
      "hasCrossWindows": true,
      "lighting": "torches",
      "hasBanners": false
    "southExit": {
      "hasFloor": true,
      "hasCrossWindows": true,
      "lighting": "torches",
      "hasBanners": false
  "rooms": [
      "type": "throneRoom",
      "hasCarpet": true,
      "linedWithColumns": false,
      "linedWithTorches": true,
      "hasSecondaryThrone": false,
      "hasMagicOrb": true
      "type": "lordQuarters",
      "piano": false,
      "clock": true,
      "bookshelf": false,
      "fireplace": true
      "type": "livingQuarters",
      "freeSpace": 0
      "type": "diningRoom",
      "luxury": 2,
      "fireplace": true
      "type": "kitchen",
      "filled": 4,
      "barrels": 2,
      "boxes": 2,
      "hasOven": true

Procedural Castle plans

Yesterday I learned about an ongoing challenge to create procedurally generated castles, over the procedural generation reddit. I’m a bit too late to the party but I thought I’d get in anyways.

I basically intend to generate topdown 2D multi level castles, similar to these found in Ultima 5 (the best game of the Ultima series).

Empath Abbey

So I went back to check the maps from the game in order to dissect their structure. You can find them here (don’t know for how long, doesn’t look like a stable location). I’m not sure who made this site, but it’s very nice 🙂

In Ultima V, the best game of the Ultima Series, most of the cities are walled and the castles and keeps have been improved greatly from Ultima IV. This is my structure breakdown, where I included elements from castles, keeps and even some walled towns:

  • Overall structure
    • 32×32 tiles
    • A wall covers all 4 sides
    • Castles are a compact structure, there’s no outer and inner wall.
    • Overall castle structure is symmetrical by the y-axis
    • There may be a moat surrounding the castle
    • Most castles have a central structure, be it a courtyard or a hall
  • Stories
    • Castles have up to 4 floors plus a basement
    • The bulk of the castle resides on the basement plus the first 2 floors
    • Floor 3 is used for the tower top of the towers and optionally the ceiling passageways connecting each
      • In some castles this structure is bigger, having most of the castle ceiling as a walkable surface instead of roof.
      • Some other castles have floor 3 as a big structure similar to floor 2, in which cases roofed walls won’t show with crenellations
    • Some central features such as a big tower can cover floor 3 and 4.
    • From high floors you can see the roof of lower floors, or the lower floor itself if there’s no roof.
    • Outer walls in floors 3 and 4 are shown with crenellations, they may also be decorated with statues
  • Towers
    • There are towers on each corner
    • Towers are connected either by covered corridors, halls or walkable wall borders. They may be connected by any of the stories they cover
    • Sometimes all 4 towers are connected, other times it’s only two (keeping the symmetry of the plans)
    • Towers are multi stories (often 3 stories) and have small cross shaped windows looking out.
    • Atop the towers there may be cannons and cannon balls.
    • Towers have stairs allowing climbing to the different levels.
  • Smaller Keep
    • Some smaller keeps may be just the four towers, the rooms below them, the halls or corridors connecting them and a central feature. They may be 1 or 2 stories.
  • Entrances
    • All castles have an entrance on the south side, some of them have an additional one on the north side.
    • The main castle entrance may be protected from the upper floors with cannons.
    • Entrances are located in the middle of the map and may have floor or grass.
    • There may be a drawbridge over a moat in the entrance.
    • Some castles have an entrance hall connecting to the central feature, in that case there may be defensive cross windows on it.
    • There may be lamps lighting the entrance
  • Courtyards:
    • A fountain or a well in the middle.
    • May have more nearby fountains in x, y or complete symmetry.
    • May have a small lake around the fountain
    • Grass with trees
    • There may be floor connecting with close rooms, or a dirt walkway around it.
    • Commonly produce a “hole” in upper levels
  • Main Halls
    • They have floor, most of times different than the used in the rest of the castle.
    • They may have a fountain the middle as well as a fireplace.
  • Rooms:
    • Staff’s Living quarters: With a lot of beds and lockers for the people’s things.
    • Guest rooms: Including one or two beds, mirror, sometimes even a piano and a fireplace.
    • Storage rooms: With lots of barrels and boxes. Commonly placed in the basement.
    • Forge: Contains an anvil and fuelled fire pit. Commonly placed in the basement.
    • Prison Cells: Divided in smaller locked barred rooms, mostly empty but may have things such as handcuffs and a watch station with a table and a chair.
    • Dungeon: Some castles have a full floor devoted to the dungeon, with lots of prison cells and torture devices.
    • Dining rooms: With different size and quality of dining tables and chairs, as well as lighting. Adornments such as fireplaces, chandeliers. Tables may or may not be served
    • Kitchens: Commonly close to the dining rooms, including stored food, tables, barrels of wine, ovens and cooking places.
    • Throne room: Long hallway with a carpet and a throne in the end. Hallway may have columns and torches on the sides. In addition to the throne, there may be additional chairs or magic instruments. They are always oriented to the north.
    • Castle Lord room: Most of times placed on a central location, it includes a bed, mirror, sometimes a piano, clock, bookshelf, fireplace.
    • Terraces:
      • Located on high places such as 3rd or 4th stories.
      • They may have a telescope and the flag of the castle.
      • May have a firepit and tiled floor.
    • Rooms may be connected with doors, open doorways or just open spaces.
  • Halls:
    • Long and wide rooms connecting rooms or towers
    • May have adornments such as torches, plants, columns and fountains.

Following with the same process I made for last year’s Ultima Underworld like generator, next step would be creating a high level castle layout generator based on this observed structure and given some generation parameters.

I am not sure I’ll be able to hit the deadline with all the scope, I’m aiming to complete the “first floor” generator.

By the way, these guys ran a competition last month to create a procedural pirate map generator. Check out the results!

qoVnH1z - Imgur