Gun Dealer features a playfield five columns wide and several rows tall. "Blocks" in the form of playing cards gradually fall into this area, and the player must arrange them into "poker hands" of three cards or more (straights, flushes, etc.) At any time, the player has a three-card "hand" displayed at above the playfield. The player can use a joystick to move the falling blocks/cards left or right, and use a button to cycle amongst cards in the hand. A downward movement on the joystick will "drop" the active card/block to speed up play. The objective of each level is to clear through a buffer of remaining cards for that level (shown by a count on the right side of the screen). At that time, the player is penalized (with a point deduction) for any cards still remaining onscreen. If, after this tally, the player's score is less than zero, the game ends. If, on the other hand, the player score is positive, the game continues and the player is treated to a soft porn intermission of a cartoon pinup girl before the next (more difficult) level begins.