GDC Tales: Pac-Man, the paper prototype
During GDC I took Marc LeBlanc‘s (and company) Game Design Workshop. One of the activities we underwent was building a paper prototype for a video game we all were familiar with. My group had very different tastes in videogames and so one of the only common interests we found was Pac-Man. We needed to act fast, and so went with it.
Paper prototyping, you say?
Paper prototyping is usually one of the first steps in the design chain, so this sort of reverse-engineering approach was certainly unconventional. Paper prototypes are commonly used to test core mechanics at a very basic level, to see if they are fun, appealing or at all interesting. With that in mind, what we had to do was identify the core mechanics in Pac-Man and try to translate them to paper.
Paper prototype, not board game!
Pac-Man being such a spatial game, it would have been extremely easy to fall into the trap of making a paper mock-up of the game, complete with labyrinth and moving ghosts. We had to avoid this at all costs; what we really needed to do was find the metaphors for Pac-Man‘s main themes and translate them into simple mechanics.
So… what is Pac-Man about?
We thought hard about this and came up with a list about what Pac-Man is about for us. So, what is it about? It is about being chased and the possibility of getting trapped. It is about collection. It is about getting the high score. It is about escaping. And it is, most importantly, about reversal. We concentrated on translating as many of these themes as possible into our prototype.
The chase
As I said before, we were tempted to draw a grid and go with a one-to-one comparison instead of a metaphor – but we caught ourselves in time. We toyed with different mechanics to convey the chase theme and initially tested with a game that went as follows: four players play ghosts, one player plays Pac-Man. Pac-Man has five chips, and they all have four cards identified as left, right, up and down. They all secretly play a card and reveal it at the same time. For each ghost that matches Pac-Man’s card, Pac-Man loses a chip. When he runs out of chips, he loses.
This was a very good first step toward our metaphor, but we were not there quite yet. After discussing possibilities, we finally ended up with a much better version, based on the game Red light, green light. The mechanic went as follows: each Ghost has five chips on a stack. Pac-Man and the ghosts play cards in the same fashion as before, and every ghost that matches Pac-Man’s card gets to place a chip on the table. When a ghost places all five chips, the game is over.
Trapped!
With our chase mechanic working, we now concentrated on conveying the feeling of getting cornered. We solved this in a very elegant fashion. The first ghost to place a third chip on the table gets to take one card from Pac-Man’s hand, which will become unplayable. Only that ghost knows what the card is, and the result is that it will make it easier for the ghost to guess where Pac-man will go next. Any ghost that places a third chip on the table gets to share the knowledge of the unavailable card. In the same manner, the first ghost to place his fourth chip on the table will remove another card from Pac-Man’s hand, and only other ghosts with four chips on the table can share that knowledge. The result is that as ghosts get closer, it becomes harder for Pac-Man to escape.
Scoring
The way we decided to score points was to let Pac-Man roll two six-sided dice at the end of every turn where he is not captured. He adds the roll to his point total.
Reversal
When Pac-Man rolls doubles, it means he has eaten a Power Pill. The result of this is that every ghost with more than three chips on the table must go down to three chips (to signify he is trying to get away). Pac-Man also gets any unavailable cards back. The Power Pill effect lasts for three rounds and during that time any ghost that matches cards with Pac-Man must go down to one chip, as a result of him being “eaten”. Pac-Man effectively becomes the hunter for three rounds.
Incentive, or weighed choices
In the arcade, ghosts can usually guess what direction Pac-Man will try to go next, based on the remaining pills. To emulate this, we thought of having Pac-Man roll a four-sided die before deciding which direction to go. The direction rolled on the die would yield double points for Pac-Man that turn, so he has more reason to go there. We did not get a chance to implement this mechanic.
It was possible, after all
We had a lot of fun translating Pac-Man into paper. We thought we would have a very hard time trying to get away from the obvious spatial mapping of the game, but at the end we managed to come up with a convincing metaphor to what Pac-Man ultimately represents. It is just a matter of being clever enough to find the appropriate metaphors and to accurately map the game’s themes to functional mechanics.
Tags: GDC 09, Marc LeBlanc, Pac-Man, Paper Prototype
April 8th, 2009 at 10:14 am
I don’t get the subtitle “Paper prototype, not board game!”. Did you had to translate the game to a paper prototype without being a board game? and if so, was a card/chips/dice game the only option?
April 9th, 2009 at 10:42 pm
@Ciro
Let me elaborate further
We were asked to strip the game to its very base and so we found that what was worth recreating from Pac-Man was the feeling of being chased and getting trapped, along with the possibility of reversal. The actual game uses spatial navigation to convey this feeling, but we really wanted to find a simpler way to recreate the same situation without having to recur to utilizing a similar 2D space, which is what a board game would have led us to. This is why we chose to search for an appropriate metaphor.
We were provided materials to work with, including chips, cards and dice, but we were free to use whatever element we wanted. Just one thing: the simpler, the better!