Pac-Man is a maze-chase arcade game with single-player and alternating two-player modes. The player controls Pac-Man, a yellow circular character who must navigate an enclosed maze while eating small dots scattered along its paths. The objective in each stage is to clear the maze of all dots while avoiding four ghosts that pursue Pac-Man through the corridors. As the player progresses, the maze layout remains the same, but the game becomes more difficult as ghost behavior, speed, and vulnerability periods change. The maze also includes side tunnels that connect the left and right edges of the screen. These tunnels can be used to escape danger, as ghosts move more slowly through them than Pac-Man.

The four ghosts each follow distinct movement patterns that affect how they chase the player. Blinky, the red ghost, tends to pursue Pac-Man directly. Pinky, the pink ghost, attempts to position itself ahead of Pac-Man. Inky, the blue ghost, uses a more complex pattern based partly on Pac-Man’s position and Blinky’s location, making its movement less predictable. Clyde, the orange ghost, alternates between approaching Pac-Man and moving away or patrolling. Their movement also alternates between periods of pursuit and brief scatter phases, during which they retreat toward different corners of the maze before resuming the chase. Contact with any ghost while it is dangerous costs Pac-Man a life, and the game ends when all lives are lost.

To counter the ghosts, four large Power Pellets are positioned near the corners of the maze. Eating one temporarily turns the ghosts blue, allowing Pac-Man to eat them for bonus points. Eating multiple ghosts during the same Power Pellet awards increasing points, encouraging the player to turn pursuit into a scoring opportunity. Eaten ghosts return as eyes to the central ghost house, where they regenerate and resume pursuit. Bonus items, usually represented by fruit or other objects, appear below the ghost house during certain stages and award additional points if collected. Depending on the version or settings, an extra life may be awarded after reaching a specified score.

The game offers continuous play with no conventional ending. After certain stages, short comedic intermissions show Pac-Man and the ghosts in brief chase scenes, serving as lighthearted rewards between rounds. As the player advances, the ghosts become more dangerous, the Power Pellet effect shortens, and eventually the ghosts no longer turn blue. In the original arcade version, play eventually reaches a famous split-screen error on the 256th board, where part of the maze becomes corrupted and the stage cannot be completed normally.

Pac-Man has been released on numerous arcade, computer, console, handheld, mobile, and digital platforms under a variety of titles and collections. Some versions closely preserve the original arcade gameplay, while others adapt the graphics, sound, controls, display options, or bonus features to suit their platforms. Early home conversions often simplified the graphics, sound, maze proportions, or ghost behavior because of hardware limitations, while later re-releases more closely emulate the arcade version.