Best way to build a sentient swarmbot in GURPS 4e?

Question

I'm trying to put together some PCs for a GURPS space opera style game I'm planning, and while I've found character creation to be amazingly flexible and detailed, there's one character I just can't seem to work out how to build.

I want to create a sentient swarm of nanites, who can shapeshift into different forms, squeeze through minuscule cracks etc. My idea for backstory is that the swarm-creature is a lost infant of a race from another galaxy; intelligent by humanoid standards but with no memories or knowledge of it's abilities.

At first I want the PC to only be able to shift into a humanoid blob (think a morph suit) and a homogeneous cloud, but over time he'll learn to assume different forms, appear different colours through the use of holographic nanoprojectors, and infiltrate computers and AI brains.

So far the best I can think of is using the Shapeshifter advantage, but that seems more focused on changing into different creatures using magic, and I want something more representative of being able to just rearrange the nanites into different shapes. I couldnt find much for a gaseous or particulate body either...

Any ideas?

Answer 1

You're correct that the first step is Shapeshifting. Any time a GURPS character has a normal form, but sometimes becomes a second, distinct form, you use the Shapeshifting (Alternate Form) advantage. If a character can turn into any form that they'd like, then they should have Shapeshifting (Morph).

I think the issue that you're running into with your intuition that Shapeshifting is "more focused on changing into different creatures using magic" is that GURPS doesn't really care about how you flavour your abilities, or what you look like in general, it only cares what advantages and disadvantages that physical form gives you. If you're an amorphous cloud that can take any shape at all, then GURPS as a system is only interested in how powerful the most powerful "shape" is. No matter what form you turn into, you need to enumerate what advantages and disadvantages are inherent to that form, so that you can know the point cost of the Morph advantage that lets you turn into that form.

You can always play fast and loose with specific point values to make the advantage easier to use in play, but at the very base, Morph lets you add a bunch of advantages and disadvantages that represent your new form.

As far as a specific form that lets you exist as a gas cloud, what you also need is a set of advantages that emulate the following abilities:

• Limited flight
• Is physically a cloud of diffuse particles
• Can pass through very small holes

The first two are easy. I would suggest Flight (Lighter Than Air) [36] and Injury Tolerance (Diffuse) [40]. For the ability to flow through very small cracks, you're going to want to look at page 53 of Powers for the Infiltration enhancement to Diffuse. In short, it's a +40% enhancement that lets a Diffuse character fit through tiny cracks.

The full Swarm of Nanobots racial template would then be: Flight(Lighter than Air), Injury Tolerance(Diffuse, Infiltration) [84]

The full advantage that lets you morph into whatever shape you like as you describe would be: Shapeshifting (Morph, up to 84 points, Unlimited +50%) [276]. You can save some points by saying that the cloud is your normal form, and that you can turn into any template with a cost of 84 or less: Shapeshifting (Morph, Unlimited +50%) [150] + Cloud Form [84] = [234].

If you instead built it as a set of Alternate Forms, it would be: Shapeshifting(Alternate Form, up to 84 points) [91]

Answer 2

Using the GURPS Powers (alternate forms, shapechanging, body of 'x', etc.,) and linking appropriate other powers (shrinking, partial insubstantial, and so forth) with appropriate limitations seems a good way to model this.

Buying off the limitations over time would then expand the abilities as the character gains xp and "matures".

(I'm AFB right now, so I'll have to look up some examples later.)