Back when the giants were raiding the human lands frequently a powerful group was formed to destroy the source of the raids. The giants were eliminated but it was discovered that they were in league with drow coming from the underdark. Taking out the giants was tough enough for the adventurers but the drow would be tougher.
A unknown human wizard crafted the Moonring to place humans on par with drow at night. Each of the counter-strike group was given such a ring to aid them in their mission. After 3 months of exploring the underdark caverns the anti-raid group of humans came out, some alive, some never to come back.
They did enough damage to the drow to prevent them from raiding again and collapsed the entrance to the underdark. Over the years each of these rings has been passed down to descendants or sold for gold. There are only 8 in existence.
Abilities: The ring allows the wearer to see at night and in magical darkness. Unfortunately a side effect is that the wearer becomes sensitive to daylight. The wearer fights at -1 to hit in the day and -2 in very bright light, a sunny day at noon, continual light in area, in a desert during a sunny day. It takes a month for the side effect to hinder the wearer and a month of not using the ring to remove the side effect.