Joust is a platforming game where the player controls a yellow knight riding a flying ostrich or stork, from a third-person perspective. Using the two-way directional joystick and the button for flapping the ostrich’s wings, the player flies the knight amidst the floating rock platforms and above pools of lava; when maneuvering off the screen to either side, the player will continue its path reappearing from the opposite side. The rate at which the player repeatedly presses the button causes the ostrich to fly upward, hover, or slowly descend. Home console versions use game controllers with directional pads or analog sticks, while computer ports use the keyboard.
The objective is to defeat groups of enemy knights riding buzzards that populate each level, referred to as a “wave”. Upon completing a wave, a subsequent, more challenging wave begins.
Players navigate the knight to collide with enemies. The elevation of an enemy in relation to the player’s knight determines the outcome of the collision. If the protagonist is higher than the enemy, the villain is defeated and vice versa. A collision of equal elevations results in the two knights bouncing off each other. A defeated enemy will turn into an egg that falls toward the bottom of the screen, which a player can collect for points. An egg that sits on a platform long enough will hatch into a new knight; if the player does not pick him up, he will gain a new mount and must be defeated again.
The game features three types of enemy knights—Bounder, Hunter, and Shadow Lord—that are worth different amounts of points. A pterodactyl will appear after a predetermined time frame to hunt the hero.
A second player, controlling a blue knight on a stork, can join the game. The two players can either cooperatively complete the waves or attack each other while competitively defeating enemies.