Dead Men Tell No Tales
Uncommon17.5%ObjectiveOptionalAnywhere
You were so preoccupied with whether or not you could open the chest that you didn't stop to think if you should.
The Dead Man's Chest is a trapped golden chest found in the underground - wired conspicuously to boulders, explosives and dart traps. The achievement is Darwinian: open it and die to its booby traps within moments. Spot one (the wires give it away), stand close, open, accept your fate. If you'd rather loot it and live, that's a separate engineering puzzle - but not this achievement.