Designer's Notes: GURPS Vehicle Builder

by Thomas L Bont and Thomas Jones-Low

GURPS Vehicle Builder is a labor of love, one I have been working on for over four-and-a-half years (the oldest file I can find in any backup is dated January 1999). This article was originally 900 words of "How do I possibly tell you what the deal is for a project of this length?" Thomas Jones-Low said, "Reduce it to one paragraph." I have found that his opinion is usually right so you just read that paragraph. Besides, it would be impossible with my meager writing skills to tell you about the trials and tribulations of the development process. Suffice it to say nobody is happier than I am that it is finally shipping.

At one time I exclaimed in a public forum, "GURPS Vehicles defies logical expression!" To a certain extent I still feel that way. There are too many options, too many expansions, too many ways to tweak the rules to fit a particular application without devoting a substantial amount of time to learning the rules and all the ins and outs of the system. GURPS Vehicle Builder, when I first considered writing this ultimate gaming utility, was to fix this. I wanted something that was flexible enough to fit just about any genre the player wanted to design a toy in, while at the same time adhering to the rules in Vehicles. This was not an easy undertaking; there are only two other people I know of that could possibly understand it at the level of the developer: Thomas Jones-Low, my compatriot; and Mike Joseph, the writer of GURPS Vehicles Designer . . . and only because they have actually seen the fruits of their labor reach the market. In effect, I wanted a program that was generic enough to be worthy of the name GURPS.

So, why did I choose to do things the way I did in GURPS Vehicle Builder? Some things are completely user-defined (though they are defined by default by us) while some things are hard-coded. The simple answer is, "because it was easy." The not-so-simple answer is, "I still haven't figured out a way to make the entire program formula driven yet." This goes back to my previous exclamation about defying logical expression. Note I am steadily experimenting with ways to completely turn all performance statistics into user-defined formulas.

By its very nature, GURPS Vehicles scares off most would-be gearheads. It is math-intensive. The math isn't that hard, though. It is mostly just the four basic operations: addition, subtraction, multiplication, and division, with the occasional square root thrown in to keep you honest. However, even a simple vehicle has over 50 formulas that must be solved, with many of them depending on an answer from a previous one. Make a mistake earlier on and your entire design is toast. Post it to a public forum and you will get some feedback on the idea but it may be days before some hardy soul will actually try to reverse-engineer it and tell you if your calculations are wrong or not. This has actually happened to me a couple of times in the early days of GURPS Vehicle Builder's development (I was trying to get some free help to test my program <grin>). It was weeks before someone said, "Hey, your air speed is wrong!" Personally, I have probably only checked half a dozen myself. This isn't because we are lazy. It is time consuming!

GURPS Vehicle Builder reduces the amount of time it takes to design a vehicle by doing the math for you (and quite quickly, I might add, in real-time as you make changes to your vehicle). There are still a few different ways to toast your design, but GURPS Vehicle Builder does try to enforce the rules for you. If you want to step outside that sandbox known as Vehicles, you can. For instance, all motive subassemblies are not truly part of the Body. They are separate entities that only contribute to total vehicle statistics. By placing them in, say, the Body, GURPS Vehicle Builder will ignore their contribution to the vehicle as a whole but affect the Body. And they do not contribute to the final performance statistics.

You may think, "This is wrong; you should be able to place them anywhere." To a certain extent you may be right. However, by allowing GURPS Vehicle Builder to ignore situations such as this it opens the door to many other options. You can create armored sections of a ship much more easily -- put a superstructure in the Body and it is treated as a separate entity for structural and armoring purposes but not used for total vehicle surface area nor is that little rule about Body volume enforced. It has its advantages at times.

GURPS Vehicle Builder also takes care of the little nit-picky parts of the Vehicles design system. What is the difference between a TL6 7.76mm Machine Gun and a TL7 model? I have no clue and neither do you unless you are a savant or happen to have GURPS Vehicles opened to the correct set of pages right now. GURPS Vehicle Builder knows.

In some ways, this program makes the vehicle design process worse by presenting you with too many options. Steve Jackson Games manages to put a new book out ever month or so with new rules, new additions, and new options that just contribute to the morass. However, before GURPS Vehicle Builder it was impossible to keep track of them all, which in a very strange way, made it easier on the designer. You only worry about the snake you know about (i.e., you only design with the options at hand). There are solutions to this problem, though.

The Steve Jackson Games solution is the Modular Design System (MDS). MDSs reduce the complexity of the vehicle design process by taking the most useful vehicle design options and wrapping them up into modules. For instance, a bridge module might consist of crew stations, computers, sensors, and communicators. This cuts down on the design complexity substantially. You find them in GURPS Traveller, World War II, GURPS Space, and Transhuman Space. GURPS Vehicle Builder fully supports the first three. Transhuman Space is coming in a later version though there is no definite time frame.

Thomas Jones-Low and I are steadily putting new items in as fast as we can get our hands on the books and type them in. As we do so, we continually find new ways to streamline the vehicle design process and implement them into the program, making the experience more pleasant for you, the user. And we do take every suggestion seriously, even if we don't use it. If you have an idea, send it to us. We'll look at it.

Article publication date: August 1, 2003

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