The four ghosts look identical apart from colour. They are not. In the original 1980 arcade game each one runs a different targeting routine, and the reason the maze feels alive - the sense of being surrounded rather than merely chased - comes entirely from those four routines interacting.

Once you know what each ghost is actually trying to do, the maze stops being chaos and starts being a system.

The four personalities

Blinky, the red one, chases you directly. His target is simply your current tile. He is the pursuer, and he is the one you feel behind you. Crucially, he speeds up as the dots run down - the "Cruise Elroy" behaviour - which is why late-level mazes feel so much more frantic than early ones even though nothing visible has changed.

Pinky, the pink one, aims ahead of you. Her target is not where you are but several tiles in front of the direction you are facing. She is trying to cut you off rather than catch you, which is why she so often appears around the corner you were about to take.

Inky, the cyan one, is the strange one. His target is computed from both your position and Blinky's: take a point a couple of tiles ahead of you, draw the vector from Blinky to that point, and double it. The result is that Inky's behaviour depends on where the red ghost is, making him erratic when Blinky is far away and vicious when Blinky is near - the two of them together form a pincer without any explicit coordination.

Clyde, the orange one, is shy. He chases you directly while he is far away, but once he comes within about eight tiles he breaks off and retreats to his home corner. Then he turns around and comes back. He is the reason the bottom-left of the maze is usually survivable.

Scatter and chase

Layered on top is a global timer. The ghosts alternate between chase mode, where they use the targeting above, and scatter mode, where each retreats to its own assigned corner regardless of where you are.

The alternation is on a fixed schedule that shortens as levels progress. Early on, scatter periods are generous; later they become brief or vanish entirely.

This is the single most useful thing to know as a player, because scatter is your free time. When all four ghosts suddenly turn and head for the corners, that is your window to clear a dangerous section of maze. Recognising the moment they turn - and they all turn at once, and reverse direction as they do - is worth more than any amount of reflex.

Why they are not random

All of the above is deterministic. Given the same inputs the ghosts make the same decisions, and their movement rules include a simple restriction: they cannot reverse direction except at the scheduled mode changes, and at each intersection they choose the exit that brings them closest to their target as the crow flies.

That is the whole algorithm. There is no randomness in normal pursuit at all - the only randomness in the classic game is in frightened mode, when the ghosts pick turns at random after you eat a power pellet.

Determinism has a famous consequence, which is that fixed movement patterns can clear a level identically every time. That is a separate discussion and it is covered in the companion piece on patterns.

Playing against the algorithms

Practical consequences you can use immediately:

  • Pinky is beaten by turning late. Because she aims where you are heading, changing direction at the last moment sends her to a tile you have abandoned.
  • Blinky is beaten by distance, not trickery. He goes where you are, so the only answer is to be somewhere else - use the tunnels, where ghosts move slowly.
  • Inky is beaten by watching Blinky. If the red ghost is on the far side of the maze, the cyan one is harmless. If Blinky is close, assume Inky is closing the other side.
  • Clyde is beaten by approaching him. Genuinely - closing distance makes him flee.

That last one is the most counter-intuitive instruction in any arcade game, and it works.

Power pellets are a resource, not a rescue

Most players eat a power pellet when they are frightened. That is the worst time to use one, because the ghosts scatter in the confusion and you collect one or two.

The efficient use is to eat a pellet when the ghosts are clustered and close, because eating them in sequence during a single frightened period scores 200, 400, 800 and 1600 - a chain worth 3,000 points against maybe 400 for a panicked single.

So the correct play is to lure them together, then take the pellet. Which means deliberately allowing a dangerous position in order to convert it - accepting risk now for a much larger payoff, timed on your terms rather than theirs.

Hoarding a flexible resource until it converts properly, rather than spending it on the first moment of discomfort, is one of those principles that turns up everywhere. It is exactly what the bonus tiles are for in tile matching - over on Mahjong, the flowers and seasons match anything and are your escape hatch, and cashing them early for a small satisfaction is how a solvable board becomes a dead one.

What kind of game this makes it

Because the ghosts are algorithmic, Pac-Man rewards learning rather than reaction. The skill curve is about recognising configurations you have seen before and knowing what they become.

That places it beside the other great arcade-speed pattern games. Spend an evening with Tetris online and the pieces come from a shuffled bag rather than at random, so a strong player is counting what must arrive and recognising board shapes rather than reacting to each piece afresh. Both games punish hesitation and reward the player who has seen the situation before.

And for the slowed-down version of board reading, with no clock at all, the logic and matching collections are the natural companion - play free puzzle games and you get the pattern recognition without the pressure.

Where to practise each ghost

The modes here isolate different parts of this. Chill slows everything down, which is the best place to actually watch the four targeting behaviours rather than merely survive them. Ghost Rush does the opposite and forces fast recognition. Night restricts visibility, which turns the game into pure prediction - you must infer ghost positions from the algorithm rather than see them. Big Maze lengthens routes and makes scatter windows more valuable.

From here

Play one round of Chill and do nothing but watch the orange ghost. Approach him deliberately and confirm he retreats. Once you have seen one ghost behave to spec, the other three become much easier to read.

The rules hub covers the modes, the ghost names FAQ covers the nicknames and their origins, the power pellet FAQ explains frightened mode, and the glossary names the terms. Play on the main game.