Mega Man X3 adopts the gameplay of Mega Man X and Mega Man X2, an expansion of the gameplay model of the original Mega Man series. These action-platform games involve taking control of the protagonist X and completing a series of eight, selectable stages.[1] Each stage has a variety of obstacles, traps, and enemy robots to fight. The stage ends in a Maverick boss fight; defeating this boss will add a new special weapon to the player's arsenal.[1][2][3] Each boss is particularly weak to one special weapon, so the player may complete the stages in an order that best exploits these weaknesses.[4] The player character X retains certain abilities from past games. Namely, he is able to run, jump, dash, cling to and scale most walls, and fire his chargeable "X-Buster" arm cannon and special weapons.[3] The player can further upgrade X's abilities by collecting armor parts (head, body, legs, and X-Buster) found within capsules in some levels.[2] Capsules containing special chips add new abilities as well. X is generally only able to benefit from one chip at a time, allowing the player to customize the character as needed.[5]
Like the two previous Mega Man X games, the player can locate power-ups such as "Heart Tanks" for extending the maximum life energy and "Sub-Tanks" for storing energy for later use.[3] Also returning are powerful "Ride Armor" vehicles that can be piloted in some of the stages.[2] Items hidden within certain levels can be collected which allow the player to summon vehicles at any time.[3] Mega Man X3 is the first game in the series which allows the player to play as X's ally Zero, although his playability is more limited compared to later games in the series.[6][7] Zero can be called to take X's place during nearly any stage, but he cannot collect any of X's armor parts or power-ups, and cannot fight mid-stage or end-stage bosses, with only one exception that grants access to a secret weapon for X. If Zero is ever defeated in battle, he will be unable to be called upon for the rest of the game.[2][3][4]