Nature's Peace is a unique Ring from Diablo II.
Most unique about Nature's Peace its ability to make slain monsters "Rest in Peace." This means that the player or any monster cannot do anything to that body, including revive it, or use a spell such as Redemption or Corpse Explosion on it. Therefore, Necromancer summoning builds especially should avoid Nature's Peace. This trait will work only if you kill the enemy with physical or elemental damage, such as with Blizzard or basic attacks, but not if they are killed with magical damage, although it will work for the Paladin's Blessed Hammer skill.