OpenArthurianX6: Design and Planning

I don’t think there’s a perfect way to approach planning this kind of project, so we’ll shoot for one, then once we have done some iterations of it we’ll evaluate and see what’s the best way to continue.

The first iteration of the engine we are looking forward to have is having all basic systems working, keyboard only, desktop only running in a browser.


One facet we are using for planning are actions the player can do


  • Move around the map
  • Pick up an item from the map
  • Examine map
  • Examine item on world
  • Examine mob
  • Read book or world feature (signpost, plaque, etc)
  • Examine world feature (find secrets)
  • Open and Close doors
  • Doors with keys
  • Doors opening with buttons / levers combinations


  • Talk with a NPC
  • Asking a NPC to join the party
  • Talk with a Party member
  • Ask a Party member to leave the party


  • Check the status of a party member
  • Set the Tactics / Manual for a party member


  • Check the inventory of a party member
  • Drop an item on the map
  • Move an item on the inventory to a container on the inventory
  • Move an item on the inventory to a party member
  • Move an item on the map to a container on the map
  • Check a container on the map
  • Pick up an item from a container to the inventory
  • Examine item on inventory
  • Use item on inventory


  • Enter and leave combat mode
  • Attack an enemy within melee distance
  • Attack a far away enemy

Engine Aspects

A second facet of planning corresponds to some features of the engine which may or may not be related to the player actions.


Moving around the map is a capability, but managing and displaying the maps themselves is an important aspect of the engine.

  • Overlay layers
  • Map transitions
  • Multiple stories
  • Day and Night Cycle


  • Follow player
  • Select action in combat mode (AI)
  • Select action in peace mode (AI)
  • Schedules
  • Action scheduling in Peace mode
  • Action scheduling in Combat mode

Use Item effects

  • Recover HP (% or fixed value, mob or party)
  • Recover MP (% or fixed value, mob or party)
  • Recover hunger (% or fixed value, mob or party)
  • Enter music mode (Play instrument with keys 0 to 9)

Use Feature effects

  • Light / Extinguish
  • Open or close door
  • Set puzzle flag

Use mob effects

  • Milk cow

The Future – Other iterations


  • Make camp
  • Board a vehicle
  • Move around in a land vehicle
  • Move around in a sea vehicle
  • Move around in a air vehicle
  • Repair a vehicle
  • Attack and object on the world
  • Ride mount

The Ancient Art of War at Westeros Part 2: The Queen of the Iron Throne

The second video for the SlashBit Retro Cinema is up!

While I didn’t invest as much time on this one as I did on the Castlevania one, this one has a long story going back to 2015 when I started working on the map hoping to have something like the video ready before the start of Season 6. That didn’t happen but I pushed forward to finish the 128×256 tiles map and then further worked on it by adding google maps support for it.


It stayed that way for over a year but with the spectacular Season 7 underway I decided to revive the project and got working on it after finishing the Castlevania one. Ashton created an extended version of the track and I made the sigils of the houses using an EGA palette. I also did some tweaks on the map graphics specially to make some castles and places look more like the ones on the series..


The first version I created didn’t have the zoom effects. I still think it looks more authentic than the final cut but the feedback I got was that it was hard to appreciate the scale of the world. I am not sure something like this could be achieved back then without a special video card, at least not on a PC with an EGA or VGA card.

I did some research in order to assign the stats for each one of the houses. Most of them are just raw approximates which I thought made sense from the little available data.


Curse of Walachia, finished

Curse of Walachia is a tribute to the recent Castlevania series on Netflix. It is loosely based on Castlevania 3 so I wondered how cool it’d be if Castlevania 3 followed the same plot as the series? 🙂

This is my first video for SlashBit RetroCinema, a youtube channel where I intend to post similar content (second video is almost ready :))

It took about 17 development days to take this from an idea to a reality. Far much more than I anticipated I would invest. I was pretty happy with the end result, but I should be more cautious in the future regarding what projects to start (since I now feel this religious duty of not letting things unfinished).

I had some plans to include all the content in the show but I had to cut it out. These plans included the catacombs stage with the cyclops boss, Sypha joining, the defense of Gresit, the deep catacombs and Alucard’s fight. I figured out this was enough to show my idea (may be I’ll do these in the future, if there’s interest on them).

Here’s the tools I used

  • JavaScript: This is actually a “playable” game which runs in a browser window
  • Arcade physics engine, timers, tiled map loading, music playback as well as basic spriteworks.
  • Tiled: To created the tile maps
  • Google Translate: To create the Engrish by translating from English to Japanese and back.
  • 8Bit Photo Lab: Nice tool I used to create the character portraits. Wish there was a Mac version.
  • Quicktime Player: To record the vid from screen capture.
  • Soundflower: To redirect audio output into Quicktime Player.

PS: The Engrish is intentional, of course.

Following are the dev chunks per day (Day 10 to 17)

Day 10

Made the weapons work. This involved positioning them based on the mob heading and position, and manually checking the collision vs targets.

Day 11 

Didn’t advance on the project itself since I jumped into the JavaScript animation side-project side-project. But started writing the intro.

Day 12

Worked on the intro.

Day 13

Finished work in the intro, including assembling some scenes. Also worked on Stage 1-1

Day 14

Level design for stage 1-2 and 1-3

Day 15

Level design for Stage 2-1 including adding the old woman dialog

Day 16

Added Trevor’s dialog to fight sequence and a lot more detail on it

Day 17

Details, Details, Details… and release!

OpenArthurianX6 Campaign Finished

After two months, we managed to raise $3,236 USD (161% of the initial goal). This will allows us to develop the engine and some tools to make it easier to create the games.

Thanks to all the contributors! I have arranged a meeting of dragons and other monsters to celebrate!

OpenArthurianX9 Contributors
All 49 contributors to the campaign

Here’s the list of all contributors! If you want to remove yourself, change your name (or include your dragon name) or put some more info. Get in touch via twitter 🙂

Black Dragons


  • Joshua Steele – Wiltshire Dragon
  • Aaron Curtis – Dark Wraith Dragon
  • C. Bruner – Spoony Spoonicus – A lover of classic RPGs with some sweet Ultima Let’s Play
  • Kenneth Kully – WTF Dragon – Maintainer of The Ultima Codex


  • Paul Lester – Vanzilar Dragon


  • Adam Westlake
  • Alec Nunn
  • Claus Kick
  • Cody Baxter
  • Devon Scott-Tunkin
  • Erwin Wolf
  • Frank Wolter – Sir Cabirus Dragon
  • Joseph Drasin – Unseen Dragon – Organizer of the Festival of the Silver Serpent
  • John Hosie – Houston Dragon
  • Madjack McMad
  • Neil Graham
  • Olivier Guinart
  • Paul Leone
  • Sir John- Serendipitous Dragon – German Ultima Games Translator


  • Browncoat Jayson
  • Helgraf Dragon
  • Jason Spangler
  • Jonathan
  • Markus Moenig


  • Christopher S Wilson
  • dgray038
  • Edgar Garcia Hernandez – Dungeon Master
  • Gallara Dragon – Leader of the Ultima Dragons Internet Chapter
  • J. G.
  • Jason Brock
  • Matt Kimmich
  • Nathan Jerpe – Developer of Legerdemain
  • Nick Walton
  • Noncho Savov
  • Roberto A Rivera
  • Ryan Szrama – Developer of Drupal Commerce
  • An anonymous Gargoyle



Sprint 1 starts next week! I’ll post an update of the project plans before that.

OpenArthurianX6 – Funded!

Big thanks to all contributors, the project has been funded…. Yay! 😀

Screen Shot 2017-07-25 at 9.08.50 PM

I’ve confirmed with Jucarave (a.k.a. Exodus Destiny Dragon), and we’ll get to work on this as soon as the campaign is over.

Now that we have reached the base goal, it would be awesome if we manage to hit the stretch goals, here’s an excerpt from the campaign:

Base Goal ($2.000)

We will deliver a free, open source game engine which you can readily use for your project including a content pack (Medieval Fantasy). This version of the engine would not include any tools to manage your game data (characters, monsters, object definitions), everything would be done at code level using data files and Tiled.

Stretch Goals

  • $3.000 – Game editor including Objects and Monsters managers
  • $4.000 – Full game editor including Character and Magic System managers.
  • Beyond – each 500$ will be used to create a new themed content pack (Space, Modern, Futuristic, Western, Steampunk, etc.)

So, if you like this kind of games and would love to see more of them being created, or if you feel you’ll like to develop one yourself, spread the word and contribute if you haven’t 🙂

Really excited to work on this and I’m glad it’s already going to be out there for gamedev enthusiasts to toy around with 😀

Javascript motion picture experiment, part 2

I wasn’t very happy with the result for my first take on the motion picture so I decided to revisit them. I did the following:

  • Remove the precision timing requirements by just calculating the film speed, position it correctly and have the shutter be triggered when the frame is passing through it.
  • Fix the shutter so that it’s not open/closed 50% of the time, instead it opens for 10 milliseconds and closes back, regardless of the desired frame rate.


Much better! if frame rate is high enough this looks pretty fluid, but may be too dark! (Note that the 1FPS example is skipping some frames, that’s an artifact of the animated GIF)

To compensate for the short shutter speed I added a white mask to simulate stronger lighting, then I increase the contrast of the film to make it look sharper under the increased lighting.

This also added a natural vignette effect to the movie. The final change I did was simulating a bit of imprecision on the shutter, making it randomly open a bit too late for some frames.

It actually looks much better when running directly (and at higher frame rates), things are happening just too quickly for the GIFs to get all important frames. I’ll clean up and push it to github soon for the curious, for the moment you can check it out online HERE.

I think I achieved what I was aiming for first, however for a real application it may be too tiring for the eyes… may be a hybrid approach (faking part of the visual effects) would be more appealing.

JavaScript motion picture experiment

While developing Curse of Wallachia, I was assaulted with a great curiosity: Would it be possible to emulate the way traditional film movies work using javascript?

The idea was pretty simple: Emulating the “film strip” as individual frames moving quickly (very quickly) on the screen, and then having an overlay area act as a shutter, synchronized with the film strip so that it showed a single frame at a time.

I decided to stream my adventure, which involved a lot of exploring the different options. You can check it out here and here

The goal was to make it so that the movie played at lower FPS than the actual game was running. I ended up doing the following calculations:


  • SHUTTER_HEIGHT in Pixels.
  • TARGET_FRAME_RATE in Frames per second


    • in Milliseconds per shutter cycle
    • Each shutter cycle consists on it being opaque and then transparent for the same amount of time.
    • in Pixels per millis
    • How quick should the film move so that a single frame is shown for each shutter cycle.
    • Converted to pixels per frame.
    • All sprites in the film strip move this distance on every frame.

Here are my observation after the first try:

  • It’s very hard to time the sprites correctly to move at this high speed and sync their position with the shutter. This is caused in part by the varying real frame rate and the high precision required for the timing.
  • Even if this was possible, having the shutter block the image 50% of the time reduces its brightness a lot (if I’m correct, they fixed this using stronger reflectors historically).
  • Ultimately, I missed the fact that the persistence of vision effect wouldn’t be achievable at low frame rate speeds so in order for this to work I’d have to work with higher frame rates, complicating the emulation even more.

I decided to give up this idea. I realize I may be doing something wrong so if someone wants to take on the challenge (or elaborate on why it’s not feasible) please post in the comments!

Later on I thought on alternatives to achieve my goal, I figured the only way to go was is faking both the Phi phenomenon and the Persistence of Vision effect as follows:

  • Keep the motion of the “film strip” using the same previous calculations.
  • Remove the shutter altogether, instead put a “still frame” sprite on top of the film strip. (This simulates the persistence of vision effect)
  • As the sprites from the film strip come close to a the “still frame” sprite, “burn” the sprite image into it. Since the film strip is moving quickly, this will simulate the phi phenomenon at lower speed (giving it the desired “retro” feel).

Here are the results:


I’m pretty happy with these results, admittedly I could have cheated and just put a blurb of pics as the film strip, since they are barely noticeable when over 8FPS… but this was fun and I think it feels more authentic 🙂

Finally, I made the still frame move around a bit when captured to simulate a bit of “jankiness” and imprecision.


If you have followed the development of Curse of Wallachia, you may have an idea what I’m going to use this for.