From presenting enemies that can attack more convincingly to the reflexive quest structure of Skyrim, there are lots of ways that game developers can make use of artificial intelligence. Michael Cook's research as part of Imperial College London's Computational Creativity Group is concerned with just one very simple application, however.
That is: can an AI design a game all by itself?
While it's a question that might sound outlandish to many though, Michael's research has already proved that such a thing is at least possible on a limited scale. Earlier this year his ANGELINA AI demonstrated platform games it had built based on newspaper articles and, while the games were certainly crude in construction, they functioned excellently as a proof of concept.
Since then, Michael's been bulking ANGELINA out with extensions such as his new Mechanic Miner sub-system -- a feature which finds new possible mechanics in properly presented engines and can then design levels to suit.
Despite all the progress made though, ANGELINA has yet to light the fire you'd expect among game developers. Aside from a few articles with provocative headlines playing off the idea of human redundancy, ANGELINA has mostly been received with ambivalence - a problem that other researchers in the field have experienced all too often.
"This is one of the problems with computational creativity," says Michael of the muted reaction so far. "Whenever you suggest a piece of software doing work independently and autonomously then professionals don't like it... [But] it's not that people are aggressive -- they just don't think that it could ever reach a decent level of quality."
"I've got colleagues who've had five page emails from professional artists outlining why they're obviously going to fail -- why they should quit their jobs and so on."
A Puzzling Present is ANGELINAís Christmas themed showcase, created as a 'collaboration' with Michael.
To focus on the question of quality is to miss the point, however. The question the Computational Creativity Group is hoping to answer isn't whether computers can design triple-A games that will render big studios redundant; it's whether creativity is a uniquely organic experience.
Can an AI experience a flash of inspiration, or is that something reserved only for humans?
"I don't think there's any difference between the human mind and a computer," says Michael, though he admits a big problem is that we still know relatively little about how the human mind works. Instead, he thinks that humans tend to romanticize their own thoughts - and he argues it's that which has caused much of the industry's indifference so far.
"This is something that comes up a lot when I explain how ANGELINA uses evolutionary systems for level design, for example," says Michael. When he explains it to people they reject it because it appears like a formalized system, not a creative process.
Broadly speaking, evolutionary systems function pretty much as you'd expect from the name; a random population of objects is assessed according to set parameters, with 'fit' instances then combined and re-assessed until a minimum quality level is attained. When ANGELINA uses such a system to create levels then it does so by creating a random population of 2D levels, then assesses them according to criteria such as 'Is Solvable' and 'Player Must Use Mechanic To Solve'. Passable results are then combined and the whole process loops again until the system is satisfied with the result.
"Because it starts with randomness [researchers] really see evolutionary systems as a good thing," explains Michael. "It's ANGELINA going through 300 random ideas, identifying the good ones and iterating forward. I don't know about you, but that's how I try to solve problems too; I'll sit and doodle."
"Good ideas aren't intentionally produced; you just recognize that one of the random thoughts you were having was good... But nobody thinks of themselves that way. They think of themselves as incredibly creative. Artists will say that their muse descended on them and so on."
A Puzzling Present features levels designed by ANGELINA, with Michael acting as a curator.
It's this sort of misunderstanding that Michael is determined to resolve. Currently he's working with local indie developers such as Alan Hazelden to see if ANGELINA can be imbued with more human-seeming attributes. Is it possible to give ANGELINA a sense of style, for example, that will make the levels it designs recognizable when compared to others? Such an approach will hopefully sift out some of the objectionable randomness, though Michael's aware that the artificiality of it may open ANGELINA to further criticism.
There's the thorny issue of creative repeatability, which has so far proved impossible to resolve. What does it say about ANGELINA that the creativity it displays can be replicated at the press of a button?
"Take The Binding of Isaac, for example. Edmund McMillen won't make another game about his experience of religion as a child and if he did then I imagine he wouldn't make another game like that," explains Michael. "But ANGELINA isn't like that; I can effectively travel back in time by faking the inputs and using snapshots of the sources."
So, even if ANGELINA were able to express a unique style then repeatability would mean that it may still seem to be the product of a system, rather than a creative process. Again, it's an issue that arises from the high opinion we have of ourselves; we think our creativity is unique and therefore valuable, while ANGELINA's is repeatable and therefore worthless; not creative. Michael insists it's an unfair assumption to start out from given that it's impossible to clarify whether our creativity is as rarefied as we think.
"People say that if I re-ran ANGELINA then I'd get the same game again, but I can't prove if that's true or not with humans because I can't go back in time," Michael points out with a sigh. "But people can always go back to these arguments... there are so many Get Out Of Jail Free Cards to oppose this sort of thing that I feel, at some point, we'll have to say we can't engage the arguments because they don't make sense."
"Some artists bring up the nature of the soul; something that is innately human, for example. That's something I feel you may as well disregard until such a point as computers are no longer synthetic," Michael continues. "Because really what you're saying there is that computers are machines and humans aren't."