It has 1050 durability and absorbs 95% of physical damage, and will also reduce the player's speed by 30% when equipped. Currently it is the strongest armor in the game, on par with Night Armor but with a penalty to speed rather than sanity.
- Because of this armor's speed penalty, it is better suited for tanking damage rather than kiting an opponent. This makes it a great asset for Wolfgang and WX-78, who can both achieve higher than average health stats. Note that both characters also have potential speed bonuses (mighty and SYSTEM OVERLOAD states, respectively), so being in these states will offset the armor's penalty to speed.
- Due to the speed penalty, it isn't practical to wear this armor all the time. Players can switch to it when they want to tank in combat. Alternatively, a Walking Cane can be equipped along with the Marble Suit, negating most of the speed penalty. However, Walking Cane is not a decent weapon for most encounters. Experienced players can mostly overcome this problem by switching to a weapon before they attack, and switching back to Walking Cane before they dodge.
- The Marble Suit was added in the The End Is Nigh update.
- As of the It's Not A Rock! update, the Marble Suit is renewable, since Marble can be obtained from Earthquakes in Caves.
- A character wearing a marble suit makes a small clanking noise.