Boots of Charging

Once per room, on the first round of combat the wearer participates in, melee damage inflicted upon the wearer is reduced by 2 points. If the wearer was struck in a Surprise round, it ends after that, otherwise the protection fades after the first standard round of combat.

The protection these boots afford lasts for just one attack. E.g., if a marilith successfully attacked you three times on round 1, these boots would only reduce the damage by 2 points.