"Mother 3" retains the turn-based battle system featured in "EarthBound." When the player comes into contact with an enemy in the overworld, the game transitions to a battle screen. Battles are viewed from a presumed first-person perspective, showing the enemies against a distorted, animated background. The player can assign each character in their party to perform an action, such as attacking an enemy or using items to restore HP or PP. Some characters can utilize psychic-based abilities referred to as PSI, which includes stronger attacks and healing abilities, and require PP to execute. Like "EarthBound", combat uses a "rolling health" system: when one of the player's characters is injured, its HP will gradually "roll" down, similar to an odometer, rather than immediately decremented. This allows a mortally wounded character to perform actions like attacking or healing themselves, as long as the player acts quickly enough. If a character loses all HP, it will become unconscious and cannot participate unless revived by another character. The player loses a battle if all characters become unconscious; the player will then be given the option to continue play from the nearest save point, but with half the DP on their person.