Toughness

Toughness represents a pet's sturdiness, robustness, and resistance to damage. Under Explore, this statistic was called Defense. Toughness is one of the options you can choose to increase when a pet Levels up. Toughness can be checked on the Pet Status screen of the Battledome, as well as the Equipment page. Virtually all Armor type items increase Toughness when equipped. These increases are percentage based, thus pets with a high Toughness rating will benefit the most from equipment bonuses.

A pet's Toughness rating (including equipment bonuses, if any) reduces the amount of damage it takes from opponent attacks. How Toughness interacts exactly is unknown; most likely it is a straight subtraction to total damage caused.

The stat booster Toughness Potion will probably be used in some way to increase Toughnness in the future; at present it is still tied to the Defense stat for Explore.