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Pac-Man Design: Hallways and Turns Level Analysis

POV: DESIGNER.  DIFFICULTY 4.  LEVEL 3 - 1 POV: DESIGNER.  DIFFICULTY 4.  LEVEL 3 – 1

A handy way to analyze Pac-Man’s maze design is to count the number of hallways, 3-way turns, and 4-way turns and then to consider their relation to each other. Turns are important to Pac-Man because every turn is the exact point in which the most meaningful decisions are made for Pac-Man and the Ghosts. In the same way players express agency with their turning and pathing choices, the Ghosts show their AI personality through the turns they take and the direction they move.

The whole gameplay experience of Pac-Man is a loop of deciding to turn or not. Figuring out the pros and cons of one turn versus another stresses knowledge about the game’s rules (complexities) and understanding of the current state of the maze, enemies, and items. Hallways (straightaways or paths with only 1-way turns) provide a nice contrast to 3-way and 4-way turns as the decision making while in a hallway is simpler (keep going forward or turn back). But keep in mind the potential to become trapped by Ghosts is higher in a hallway as there is only one entrance and one exit.

The Pac-Man Arcade maze has the following features:

4 4-way turns
22 3-way turns
26 1-way turns
15 longest hallway(measured in dots)
240 Dots
4 Power-Pellets

The relationships between the numbers described above give the original Pac-Man level its maze feel and well-tuned gameplay. Notice how most turns are 1-way and 3 way. The abundance 1-way turns makes it so that the player’s fingers are rarely idle. Though moving through a 1-way turn doesn’t involve much decision-making, it does require timing. If players don’t give a MOVE input at a 1-way turn, Pac-Man will just sit there and waste time.

The abundance of 3-way turns means players will frequently make a relatively simple choice; turn into path A, B, or turn back around for path C. Because players are typically being chased by at least one Ghost and the goal is to move forward through all the dot lined paths of the maze, a 3-way turn is mostly about choosing path A or B. While it’s easy to pick the option to avoid running into a nearby Ghost, planning ahead even a few seconds into the future is increasingly complicated. Accurately predicting Ghost movement requires understanding the AI mode timer, current level of difficulty, each Ghost’s AI personality, and a few other special rules discussed in part two of this analysis. In practice, the player chooses quickly, moves swiftly, and watches the results of their turning decisions unfold before their eyes.

Here are a few other details about the original Pac-Man maze:

  • Power Pellets are placed near the corners of the map, in hallways, away from warps, and surrounded by a combination of 4-way and  3-way turns.  This placement ensures the most decision making when going for the power-pellet and the most escape options for Ghosts as they retreat in the frightened state.
  • There are empty areas of the map (leading into warps and around the Ghost House). This design keeps the warps optional while giving the bonus fruit an area to spawn that Pac-Man wouldn’t be incentivised to travel through otherwise.
  • When Ghosts switch to the scatter AI mode they move to their home corners on the map ignoring Pac-Man. This movement also means the Ghosts go on patrol in the areas around the power-pellets. So even when they’re not chasing Pac-Man, Ghosts naturally protect Pac-Man’s greatest weapon against them.

 

4 4-way turns
20 3-way turns
19 1-way turns
17 longest hallway
(measured in dots)
270 Dots
5 Power-Pellets

The Google Doodle Version of Pac-Man (play it here) does a pretty good job creating interesting gameplay.

The biggest problems I have with the Google Doodle maze design is the concentration of turns and the placement of the Ghost House. Creating a maze out of the Google logo involves a lot of horizontal hallways. The Roman alphabet tends to create horizontally-oriented blocks of shapes. Hallways are great as a reprieve from continuous Pac-Man turning, but not as roughly half the maze paths. Basing the maze design around the Google logo also is why the Ghost House is made out of the lowercase “g” instead of the yellow “o”. The Ghost House functions best in the center of the maze so that the ghosts have the shortest distance to travel to Pac-Man once they exit. When navigating the left side of the maze in the Google Doodle Pac-Man game, consumed Ghosts are less threatening as they take more time to travel to the Ghost House and back to Pac-Man. When this happens, the gameplay experience becomes dull.

Real-life roadways, however, are not designed to challenge our brains. In fact, most streets are designed to be as simple and as straightforward as possible. This is great for modern living. It’s terrible for Pac-Man maze level design. Straight hallways in Pac-Man are death traps because they allow for very little decision-making while inside. Real-life roads are generally spaced apart from each other, further reducing the concentration of corners and turns, limiting how often Pac-Man can juke ghosts to buy more time.

It doesn’t help that the warps are unintuitive due to the lack of symmetry between entrances and exits. Sometimes entering the same warp can spit Pac-Man out of different exits. The Power-Pellets are placed randomly it seems. Sometimes they’re in a hallway; sometimes at a 3-way turn.Since the abundance of hallways means players will have less ability to out-maneuver Ghosts, grabbing the Power-Pellet becomes either necessary for survival or a boring choice–there is no expedient way to maneuver around the Power-Pellet to save it for later. Ultimately, the Power-Pellet placement algorithm results in fewer Ghost chases and fewer exciting situations where Pac-Man barely turns the table on ghosts who are rapidly cornering him.

For these reasons, most of the Google Map Pac-Man levels I’ve played have given me little fun and much frustration compared to the original Pac-Man maze. Procedurally-generated level design is harder to execute well for games that have deep and complex gameplay. With mazes designed from road maps, the algorithms Google used to generate the Ghost House, Power-Pellets, and warps don’t produce levels that support interesting gameplay.

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Pac-Man Design: Arcade. Doodle. Map. Mechanics

POV: DESIGNER.  DIFFICULTY 2.  LEVEL 1 - 1 POV: DESIGNER.  DIFFICULTY 2.  LEVEL 1 – 1

On May 21st 2010 Google cost the world $120 million. I remember it as the day I visited google.com and found a playable version of Pac-Man in place of Google’s logo. The doodle wasn’t any larger than the normal logo, but the faithful recreation of the sights, sounds, and gameplay of Pac-Man took me from yet another Google search to a glimpse into my past. Now, about five years later, Google has outdone itself with another Pac-Man project.

On April 1st, 2015, I got to play Pac-Man through the streets around my apartment, the DFW airport, and exotic locations around the world via Google’s April Fools’ Day promotion that created Pac-Man levels out of map data.

Between the original Arcade version of Pac-Man and the two Google Pac-Man projects, we have the perfect case study to examine the design of this classic. Because Pac-Man is a relatively simple game, we can dig deep into its entire design and highlight how the small differences between Google’s recreations and the original game make a big difference in the player experience. In this article, I’ll cover the basic mechanic of Pac-Man and build from there in future posts.

There is only one mechanic in Pac-Man; MOVE. No jumping, punching, or shooting. Just moving up, down, left, and right with no momentum or acceleration to worry about. In fact, You don’t even have to hold a particular direction since Pac-Man continues to move in the direction he’s going until stopped by a wall or a Ghost. What’s great about Pac-Man, and what creates gameplay of interesting choices, isn’t deciding how to move, but deciding where to move and when. Still, with controls so simple, there are a few subtle details in the tuning of Pac-Man’s MOVE mechanic we should cover.

In the original Pac-Man arcade, the entire game is designed to fit onto a grid. Pac-Man and the Ghosts are one square large. The walls and lanes are also mapped to this grid so that all movement through the maze is both clear in how it communicates travelable spaces, and clean in that there are no sprite edges to get hung up on as Pac-Man rounds corners.

To make movement even smoother, players can input the direction they want Pac-Man to move before Pac-Man reaches a turn. Doing so allows Pac-Man to turn the corner as quickly and efficiently as possible. This leaning into turns due to the buffered input helps reduce the skill needed to make efficient turns thus freeing up the player’s attention to focus on the strategy of surviving the maze.

The Google doodle nails the controls of Pac-Man. It’s free and you should play it right now to remind yourself how smooth controls lay the foundation for smooth gameplay. Treasure the finely tuned controls while you have them because the controls in the Google map Pac-Man are frustratingly bad.

The core creative conceit of Google Maps Pac-Man (GMPM) is obvious: play Pac-Man out on the roads of the world. The organic geometry of roads, with curves and many-way intersections at odd angles, significantly complicates the control design of Pac-Man.

There are two facets of controller design to focus on here: directness and intuitiveness. Controls are direct when mechanics (player actions) are designed in a way that matches the input method. For Pac-Man arcade version Pac-man can only ever move in a cardinal direction, and an arcade stick allows only cardinal directions, thus forming a perfect mapping. In other words, the player cannot manipulate the input in a way that can’t be reflected in the game. Pressing up moves Pac-Man up always. This design also makes the controls intuitive.

In GMPM, even the controls are not as direct or intuitive as the Pac-Man arcade version, and I blame the curves. When you press up on the Google Maps version, Pac-Man’s path can eventually curve so that Pac-Man moves left, right, down, or any angle in between. Pac-Man will keep traveling down even a curved path automatically. But it’s when I attempt to buy time by moving back and forth along a single curved road that the lack of directness becomes troublesome. On a curved road do I press left-right-left, up-right-up, or some combination of diagonals?

Diagonal road intersections are especially frustrating in GMPM. It’s hard to tell if you should press one or two directions to make a diagonal turn. Because the turns can branch off at any angle, even adding diagonals through 8-way movement controls won’t eliminate ambiguous turns. Since you often can’t tell where Pac-Man will go at an intersection if you hit a certain direction, playing Google Map Pac-Man becomes more about how to move instead of just when and where.  

D-pads are the best input device for instantaneous movement at constant speeds and quick, repeatable discrete movements along 4 axes. Curved movement in games necessitates the use of more complex rules to govern movement that tend to benefit from more complex control input devices like analog sticks. Fortunately, the Google map Pac-Man offers mouse control. With a small yellow arrow indicating the direction Pac-Man will move if possible, the mouse helps players navigate curved paths and angled turns with greater accuracy than the digital arrow controls. Unfortunately, because the mouse is a relative pointing device, Pac-Man will attempt to move toward the mouse cursor at all times. This means you can’t simply move down roads by tapping a direction and taking your hand off the controls. If you aren’t constantly adjusting where the mouse points, Pac-Man may take turns or even reverse direction when unintended. The worst case of this is happens when Pac-Man moves off the edge of the screen–where he ends up is often asymmetrical to where he came from and unpredictable. Keeping control over Pac-Man via mouse position tends to require quick and precise mouse movements. During these brief moments, I feel like I’m playing a first person shooter, not a maze runner.

For the Google Map Pac-Man I like the arrow keys for their simplicity, but I end up using the mouse controls for their accuracy.

 

Controls and mechanics are the first step to understanding a game. In part 2, we’ll look at what makes Pac-Man gameplay so interesting