Papers · Thoughts

Thoughts on Procedural Content Generation

At the end of May, I gave a presentation on the underlying systems and tools that we used to develop the games Symon and Stranded in Singapore at the Procedural Content Generation workshop during the Foundations of Digital Games Conference. Most of the other presenters were computer scientists, as well as my friends. Thus I had a kind audience for this humanist to present the paper I wrote with Alec Thomson (now available online). Feeling a bit of the outsider in terms of background and methods, I also sensed the cultural differences between their approach and my own. In general, the presentations  focused on generating the game (including mine). What I found considerably absent was a discussion of human factors: are these games playable? How does PCG transform how we make games? How does it change how we play them?

The workshop obviously had a technical focus, so when it came to talk about evaluating the systems, the discussion focused on how AI solvers / computer players were used to see if the game generated is consistent. Few of the presenters seemed to have used human players (more sophisticated and accessible AIs which you don’t have to implement) to evaluate their systems. On the other hand, there were presentations that dealt with the systems exclusively, not really dealing with why this approach was better for games apart from the pre-existing arguments efficiency in creating more content with smaller teams.

I guess that the presentations at the PCG workshop were clear examples of the  proceduralist stance in game development, since the discussion of players seemed to be out of the question. Many of these presentations are more hypothetical, and implemented as early prototypes, still far from being actual games. I’m not saying that this is bad, we do need this kind of studies and tools. It was also the nature of this seminar, which was grounded on computer science, and the expectation seemed to be focusing on the systems and not players.

Throughout the workshop it became evident that we also need the space between procedural generation of content and evaluating that content through playtesting. After two years of working on games using PCG, the conclusion is that, in our case, we can generate procedurally generated narrative puzzles. It’s a lot of work, but it’s true it’s only half of the work. The other half is making them playable and fun. For that, I have less faith on AI and more on actual humans designing and playing.

I’m advocating the creation of a research space closer to HCI, where we study how procedural generation actually affects game design and gameplay. There is a need to study how the process helps both designer, the design process and the players. We need to see this in games that can go beyond academic experiments, that are played by people who don’t know and probably shouldn’t care that these games are part of research. Reaching out beyond the academic sphere is not easy: there’s Facade and Prom Night, and my own games Symon and Stranded in Singapore. (If there are more, please let me know in the comments!) We cannot feel snug about creating a system and making a game that our friends will play. If we want to make an impact on game development and design, we must take it a step further, we need to evaluate how games using PCG are played by people who are not those who developed the system.

There are already some easy questions that we can start looking into:

  • If we think of content as something like puzzles, or level design, how do we provide cues for interaction to players? Think of hints to solve a puzzle, or user feedback about where to go. This is a common problem–Gillian Smith had run into these issues as well during the development of Endless Web. We can certainly design a system to provide these cues and feedback, but the best way to do it would be studying how players interact with the game first.
  • What are the aspects of game development that can use procedural generation best? Design? Art? Code? QA? Writing?
  • All the designers I can think of working on PCG come from computer science. How can we make procedural content generation accessible to non-programmers, or at least people who don’t have a strong background on CS?
  • What mechanics and fictional worlds fit PCG best? I believe PCG is one approach to game development, but not the only one. After working on Stranded in Singapore, one of the conclusions was that it was really hard to design puzzles to be procedurally generated when they were based on the real world. Dreams, on the other hand, seem to be a good match for PCG, as seen in Symon and Endless Web.

These are the immediate questions that come to mind, based on my experience making games. I have a few preliminary answers for some of these,  but we need to expand our thinking on what PCG means with relation to games.

The workshop taught me (amongst many other things) that many of the people working on PCG already take playtesting as part of their process. There were also slides that made my blood curdle, which reduced human behaviour to mathematical formulas. One presenter had a formula for “fun” depending on the type of player (who I’m guessing it’s also determined with another mathematical formula). Another presenter called the story “filler” in the context of RPGs, which can be just generated to give you a motivation; when I called him out, he admitted that it may not be the best term. The fact that human feelings and behaviour are reduced to numbers, and that narrative is considered filler, may be symptoms of the subconscious disregard certain computer scientists may have for human behaviour. This is one of the dangers of focusing on the procedures so much: look at the screen for too long and one loses sight of play as a human activity, doesn’t question how our brains and hearts fill the gaps so that we don’t have to really generate all the content, and stops giving enough credit to players. By approaching fun and storytelling as things that are generated mechanically, negating that fun is an awfully vague concept (and non-quantifiable), and that stories are not only about events but about worlds and the people in it, we’re heading towards playing with mathematical formulas empty of human meaning.

I’m probably preaching to the converted–most of my friends working on PCG will talk about their playtests and what they learned from them. This post is calling out a certain type of discourse which, also necessary, also seems to leave out the humanity of games. Rather than complaining (too much) about it, we should see this as an opportunity to opening up a new area of study. The combined study of procedurally generated content and human-computer interaction is waiting to happen.Who’s up for it?


How I Started to Study Games

I realized videogames have been my subject of study for the last 10 years. At first, they were a secondary field of interest while Shakespeare on Film was my research focus; I went on to study games full time in 2004, when I started my PhD in Digital Media in Georgia Tech. Now my professional life revolves around videogames.

I can remember the moment I realized I wanted to study games. Although I do not recall the exact date, I remember it was a Friday afternoon in late May, during the doctoral seminar on early Gothic Literature. It was hot, and I felt rather spacey. We were discussing several short texts in class; and one of them was “Sir Bertrand, A Fragment” by Anna Laetitia Aikin. This was one of those short stories presented as a “found fragment,” in order to lend some minimum credibility to what is really a fantasy story.

During the discussion of the piece, I commented that the story reminded me of a videogame. Sir Bertrand enters this castle, following a light, and gets to a vault where a living armour attacks him:

“The vault, at length, suddenly opened into a lofty gallery, in the midst of which a figure appeared, compleatly armed, with a terrible frown and menacing gesture, and brandishing a sword in his hand.”

It was the following sentence that (literally) gave me the key:

“Sir Bertrand undauntedly sprung forwards; and aiming a fierce blow at the figure, it instantly vanished, letting fall a massy iron key.”

Growing up playing videogames, I had seen this a thousand times: I fight an enemy, I kill the enemy and bleemp! there was an item that I picked up and used somewhere else. It gets better: the key opens a “brazen lock” which takes Sir Bertrand to the next room, where a coffin appears. It would be trite to think that  Dracula was going to jump out of the coffin. But no! It was a lady in distress, and as the player Sir Bertrand gets close to it, two large statues come to life and brandish their swords. A timely kiss makes the whole place collapses before the statues get to him.

The scene just felt like the beginning of Vampire Killer (the original Castlevania, people, but that’s another story). The elements were familiar: arriving to the castle, enemies attacking you that “drop” items that you can use to advance in the game, there’s even a coffin! I made my case to my professor, Manuel Aguirre, who did not know much about videogames. My exact argument was probably delivered though a siesta cloud, whose dreamy mood inhibited my talking clearly. The sleepy rambling would have gone unnoticed, if it weren’t for my professor intently listening to me, encouraging me to keep talking and, worse enough, bringing up Propp’s Morphology of the Folktale. My paper for that class ended up dealing with the relationship between arcade games (or what we call in Spain “arcade games,” which are 2D action games and do not have much to do with actual arcades) and how they replicate (or not) the structure proposed by Propp and Joseph Campbell. (Later we realized it’d be difficult to justify the relevance of the paper to the seminar, but both my professor and I were too enthusiastic about the topic to consider such trifling matters.)

I took this seriously enough that while I was still in Spain I went back to playing videogames, and catch up with what I had missed while studying my undergrad. Games then were a vastly unexplored field, and there was so much to learn. Since in my work then I studied theatre and was part of the drama company in my school, I started musing whether one could make games as part of studying them. When one of my (most mediocre) professors heard I was coming to the US to study, he came up to me and told me that I should forget about videogames, they were a waste of time, and I should stick to Shakespeare. That was another spur to move into games. I still love my Shakespeare, and at times I miss being in a field where there is a tradition and you don’t have to define foundational terms. But I would be very bored without the challenges of studying games.

So that’s where I began. It’s been a long road, and at times I feel like I spent forever in graduate school, but on this journey I’ve also learned a lot about games, players, and the culture surrounding them. Since some of the ludologists not only have admitted that games do indeed relate to narratives and have started applying narratological frameworks to games, now it seems okay to say that one started studying games as narratives. What I started by following Sir Bertrand as a player character was relatively basic; ten years later, the adventure goes on.

So, if you study or work in games, what’s your story?