Defense

From the Super Mario Wiki

Defense points are used to cut damage dealt to a character or enemy. In Super Mario RPG: Legend of the Seven Stars, there was both Defense for normal attacks, and Magic Defense, for decreasing damage taken due to magic attacks. In the Paper Mario series series, a Defend Plus (P) decreases damage by 1, but it excludes magic attacks that pierce defense. In the Mario & Luigi Series, defense would still decrease damage, but all attacks that hit Mario or Luigi did at least 1 damage. However, the player could cause Mario/Luigi to take 0 damage by dodging or deflecting the attack, which would work regardless of Mario/Luigi's Defense level.