The cunning plans of Sol Trader
I’ve just finished reworking the old state-machine based AI system that I threw in to the game last year just to get something working. Sol Trader now boasts a full STRIPS-based planning AI. This works by starting a character off with some basic needs to fulfil: the need to socialise, rest, work, self-improve, etc. It then uses pathfinding techniques to work out a series of steps to get those needs fulfilled, such as buying a cheap good and selling it for more somewhere else, hitting the bar after work, or hanging around a jumpgate looking for easy prey. Here’s how it works.
Making a plan
Let’s say Anthony, an AI character, is tired and has a strong need to rest. To fulfil that need, the game allows the character to rest at home, but also to stay a night at a friend’s house. Here are some rules from the actual planner in the game written in a semi-formalised manner:
- in order to
RESTwe canRELAX_AT_HOMEif we areIN_LOCATION(MY_HOME)at cost of 0 - in order to
RESTwe canSTAY_A_NIGHTif we areAT_HOME_OF(CLOSE FRIEND)at cost of 50
To stay the night at a friend’s house, Anthony would need to move to their house, so we need some more rules to cover this:
- we are
AT_HOME_OF(PERSON)if we areIN_LOCATION(PERSON) - in order to be
IN_LOCATION(LOCATION)we canMOVE_TO(LOCATION)if we areIN_CITY(CONTAINING LOCATION)at cost of 10
Let’s assume that we are already in the city in question. The planner starts off at the need (REST) and works backwards until it find this IN_CITY state. It then forms a chain of actions to complete to get the need fulfilled:
ANTHONY'S PLAN: MOVE_TO(HOME) -> RELAX_AT_HOME -> FULFIL_NEED(REST)
The game will always chose the lowest cost option. If Anthony is in his home already, or in the same city, then he would just go home to rest, rather than to a friend’s house. However, let’s assume he is in a different city. It’s too far for Anthony to head home to his house, so the lowest cost option would then be to trespass on the hospitality of a friend who lives in that city.
Planning works extremely well for Sol Trader
There’s no one-size-fits-all when it comes to good game AI. The effectiveness of AI techniques varies dramatically depending on the type of game being designed. However, planning is a great fit for Sol Trader: it’s had a dramatic effect of the feel of the game.
Now the AI is now intelligently making decision based on relative needs, the game has the following new features, all of which were easily added:
- Characters now visit friends and colleagues, hiring ships if they don’t have their own transport
- Traders buy and sell goods intelligently, by buying cheap, travelling to another planet and selling high. It’s great fun watching the ships take off and land, knowing they have a cargo full of cheap goods bound for some far-flung planet, which will actually be more expensive in their destination.
- Navy ships now take off and escort famous characters.
- Unwise navy characters might take the law into their own hands, destroying ships close to them that contain characters they know to be immoral.
- All ships defend themselves when attacked, depending on their piloting skills and their wisdom
- Characters will run to a planet for repairs should their ship get too damaged.
- I’ve also got the bare bones of the Pirate AI in, so you need to watch out when travelling around the various systems now: I’ve already been attacked once whilst trying to test something else. They’re not that smart yet, and will attack even in major population centres, but I’ll fix that in an upcoming release.
It was also very easy to put in a conversation option which asks what a character is thinking about. This returns some text detailing the character’s top need, which shows what they’re most likely to do next:
I’ve posted the start of a reference guide to the forums for modders.
This new build is now available from the forum if you have purchased insider access (if you haven’t there’s still time!) If you are already a Kickstarter backer and you haven’t received your copy, or you’re a member of the press, do get in touch.
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Ealdorlight: A Kickstarter retrospective
It’s now been over three months since the end of the Ealdorlight Kickstarter campaign. I’ve deliberately been taking some time to think and learn from the fact that it didn’t reach the target, and to work out what to do next. Frankly, I was pretty upset that the campaign didn’t make it, and it’s taken a while to get over it.
It’s also taken a while to think through the campaign properly. Some things are obvious in hindsight, and others less so. A lot of post-Kickstarter analysis feels like a stab in the dark. Nevertheless I’ve given it a lot of thought, and these are my best guesses for why I think Ealdorlight’s Kickstarter failed:
Read moreEaldorlight's Kickstarter is live at 4pm today
The sixth of June is a significant day for me personally. In 2004, I spent the entire of the day in hospital. I remember the 60th anniversary commemorations of D-day on the TV in the background, as I sat beside my wife, in labour with our first child. I became a father an hour after midnight on the 7th June; my son becomes a teenager tomorrow.
Twelve years later, in 2016, I spent the entire of 6th June glued to Steam watching and waiting whilst my first game Sol Trader was released to the world. This was a career dream come true: since I started programming at six years old I’d always wanted to create and ship my own games. Sol Trader’s release was ultimately a painfully formative experience for me, which I wrote about at the time and was interviewed about recently in GamesIndustry.biz.
Over the last year, I’ve been keeping busy doing two things. One is to support Sol Trader as much as I can with countless updates and patches. I’ve also been very busy working on a new game, Ealdorlight, a medieval RPG-style take on Sol Trader’s mechanics, with turn-based combat, realistic damage and great graphics. I announced Ealdorlight in March and demonstrated it at Rezzed, strengthening my hope that the idea was a good one.
I decided fairly early on that I wanted to take Ealdorlight to Kickstarter. Sol Trader’s successful Kickstarter was a brilliant experience. The Kickstarter community is one of the kindest, most positive on the Internet. I also needed funding for this game: Sol Trader was self-funded through many long evenings and contracting work, and for Ealdorlight I need a bigger team to realise the vision. It’s built in Unreal Engine 4, which simultaneously saves me loads of development time and means I need a bigger team to pull off the realistic art style I’ve gone for.
As time came near to launch, the first anniversary of Sol Trader’s released seemed an appropriate day to launch the campaign. So today, 6th June 2017, I will spend the entire day glued to Kickstarter as my campaign goes live at 4pm today.
Visit Ealdorlight’s Kickstarter Campaign
There’s plenty more about Ealdorlight on the campaign - head over there and read all about it! A huge amount of work has gone into it, and I’m very grateful for all the support and help I’ve received from the team I’ve put together, and for friends and family who have given me endless encouragements and feedback.
This post is a little earlier than 4pm so that you can watch it go live if you want. Earlier backers get lower edition numberings on some of the rewards, so you might want to be there from the start!
Read moreHow Ealdorlight's story stands out
As we head towards the Kickstarter campaign launch on June 6th, I want to talk a little about the story behind Ealdorlight works.
The basic story stays the same for each game: you are discovered wandering through a remote village at a young age, and realise your destiny is to overthrow the King. However, like in Sol Trader, every person you meet is randomly generated. This means that your real identity will be different every time, and you’ll have to discover it all over again every time you generate a new game.
Handcrafted story in a random world
The trick is layering a great story on top of a generated world with random characters. Building empathy with the main character and his family when all characters are generated is hard, and hinges around being able to hook the story in at the right moments.
My plan is to write plenty of tightly connected story arcs that are triggered on events that happen during history generation. These will in turn trigger future quests the player can undertake. Not all story-arcs will appear in every game: it will depend on how the history generation goes. I will constrain things such that there is always a route through the game, and that players always have a way to overthrow the King, even if that might be easier or harder depending on the starting setup. These story-arcs then should interact with each other, hopefully producing a unique path through the game.
Identity
Ealdorlight is set within a low fantasy world, and there’s no traditional magic. The player gets more powerful through discovering key pieces of knowledge about their past. These insights into of your real past feed directly into your character’s stats, skills and abilities.
I’ve long been fascinated with identity: knowledge of who we truly are affects many areas of our lives for the better. In Ealdorlight I wanted to tell a story which takes this to an almost supernatural level. By removing the player from their birth family, they start as an entirely normal person within the world. It’s only after their early game encounter with the Ealdorlight and the discovery of their past that things begin to change.
Much more on this to come, but in the meantime, here’s a glimpse of our story’s beginning.
Ealdorlight: backstory teaser (updated)
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Ealdorlight Kickstarter on 6th June, Sol Trader 1.3 released
I am now back from some extended time away after Rezzed, both on holiday with the family and training some clients away from home. I’ve released Sol Trader 1.3 today, and set the Kickstarter for Ealdorlight to 6th June.
Rezzed was fantastic: it was great to see lots and lots of people wearing our Ealdorlight crowns. We ran out of crowns on both days, with some creative head displays on offer:
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Ealdorlight Kickstarter launch date: 6th June
Yes, I know I said May :) I’ve decided to go for a 31-day campaign, starting on the 6th June, for a few reasons:
- It doesn’t clash with any major US holidays, like Memorial Day. The 48-hour reminder email should go out on the day after 4th July.
- I want to give myself the best chance of success by polishing the combat demo hard. It was great to get such good feedback at Rezzed and I think it’ll be a great hook. I need more time to do that well.
- 6th June is the first anniversary of Sol Trader’s launch, so it ties in nicely with the ongoing Revelation Games story.
I’m excited and nervous about this Kickstarter campaign: my third one to date. After succeeding last time I’m really trying to take my time and get it right.
Sol Trader 1.3 released!
Now that I’m back, I’m able to support a new release of Sol Trader: 1.3 is now finally released after a length beta period.
Here are the highlights:
- You can now chat to characters directly on the right if they’re in the same location as you
- Pirate Chief and criminals are now more likely to try to destroy you
- Fix a bug where you’re not paid enough for a mission
- Dignitaries now fly around a little less than before to make it easier to pin them down
- Inter-faction missions now pay slightly less
- Business trips now pay slightly less
- Taxi missions now pay slightly more
- Talking to your criminal parents will no longer cause them to forget who you are
- Fix crash where a character develops an opinion of the player mid-conversation
- Fix crash when showing GUI for a ship the AI is driving
- Fix crash where a character would attempt to sell a good on a ship they’ve lent to the player
- Can now initiate conversations when paused - will restart the game but at realtime speed
- Fixed the Tiger II achievement
Your steam copy should automatically update. I’ll be releasing an updated downloadable version to SendOwl in the next few days.
Read moreIntroducing: Ealdorlight
I’m very excited to be able to announce my new game…
Ealdorlight is a single player RPG set in a low fantasy kingdom where you must influence, cajole and fight your way to the throne.
Players travel the land, meet characters, perform quests and attempt to discover their true identity, different every game. Learning about the pasts of other characters gives the player influence over them, and learning who they truly are allows a player’s character to become more and more powerful. Along the way they will discover ancient weapons with hidden pasts, recruit allies, fight those who get in their way, and finally build a strategy to overthrow the King.
Ealdorlight generates centuries of history and society each game, giving players a whole kingdom of characters and relationships to explore and exploit, with turn based story-focused combat and an open quest structure.
Find out more info on the website!
Development plan
The plan is to put the game back on Kickstarter in May. Kickstarter was awesome last time for Sol Trader’s campaign - I think that the Kickstarter community is one of the best on the Internet for encouragement and positivity. I also want to check in with gamers to make sure the game I’m planning is the one people want me to make.
I’m building this game in Unreal, although parts of Sol Trader’s engine will make it into the game. Using Unreal has been a great experience so far. I’ll post tips and other learnings here as I go, as well as some thoughts on why I chose it.
I’ve already had some very helpful feedback on the idea and am looking for more - what thing about Ealdorlight most draws your attention?
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