DEF-Down

DEF-Down is a status ailment that has appeared in several Mario RPGs. It is an abbreviation for "Defense-Down".

Mario & Luigi: Superstar Saga
Some enemies have the ability to change the Mario Bros' stats. If their defense power goes down, enemy attacks will do more damage. The ailment is indicated by a gray block with an arrow pointing down.

Luigi's Thunder Bros. attack can give this status to enemies.

Mario & Luigi: Partners in Time
DEF-Down is the same status ailment in this game. Its indicator is a shrinking green circle around the afflicted. Ice Flowers can randomly inflict this status ailment on enemies.

Mario & Luigi: Bowser's Inside Story
Again, DEF-Down makes an appearance. Green streaks flowing downward indicate the affected. Many enemies can inflict this status on one of the bros. One of Mario & Luigi's special moves, Falling Star, can inflict this status on enemies.

Mario & Luigi: Dream Team
DEF-Down once again makes an appearance, visually the same as Mario & Luigi: Bowser's Inside Story. Many enemies can inflict this status on one of the bros. This status can be inflicted on enemies using a Virus-Master badge combo, or a Risk-Bronze badge combo (though the latter is less likely to do so, and it can affect the bros.)

Paper Mario: The Thousand-Year Door
The status ailment returns in this game and serves much the same purpose. It is indicated by a gray diamond with an arrow pointing down. Using a Mr. Softener can give this status effect to enemies, however, the enemies can also do the same to Mario.