A Sarvas Sword is a classic, slightly magical longsword (longsword +1 in D&D terms). It has no special properties aside from being exceedingly well-made and very sharp. What makes it notable is that there are several dozen of them in existance, and they are all nearly identical.
During an ancient Elf-War, the mighty wizard Sarvas was commissioned to make a weapon for the armies of King Sarathas of Silverwood. He made a few mighty weapons for the King, but making them was time consuming and exceedingly draining. He experimented for several months to find a more efficient way to create magical weapons for the elite but small Elven armies.
What he developed was a magical Forge, which bears his name, capable of producing many identical magical swords in a relatively short period of time. Those swords the Forge made were distributed to the armies of the Elves. The Forge of Sarvas was totally unique (and some claim the work of the gods) and lost to time long ago, but not before it created hundreds of these swords. Over the eons these swords passed on to other owners, either becoming dispersed into treasures, the hands of warriors, or lost forever.
Each sword is, as stated above, identical. They are finely crafted, well-balanced and exceedingly strong. They have one bloodline down the center, a utilitarian steel hilt, and old Elven runes identifying their creator, Sarvas, inscribed on either side of the blade. The only things that differs from sword to sword is the wrappings of the hilts (the original leather doesn’t remain) and whatever nicks and dings the sword recieved in its life.
Purpose and Uses:
This is an unoriginal item. It is a longsword +1 with a simple backhistory. Why use it? Why value it? Most fantasy worlds are besmottered with minor magical items of unknown origin and seemingly made only to be cast away into treasure hordes. Who is this mighty wizard creating a proliferation of (relatively) bad magical weapons and distributing them to the world? Why would they not be improved by their owners? Why would there be so many of them? This weapon begins to answer some of those questions, as well as give any campaign setting you introduce them to an interesting flavor (oh, he has a Sarvas Sword too!).
—Somewhere the Forge of Sarvas has been found and is being put to use creating a new wave of swords for an evil army bent on uhh… evil. The PC’s must rush to the rescue
—An eccentric collector is trying to assemble a collection of them, and is willing to buy the PC’s magical weapons from them, as well as pay them handsomely to retrieve more of these swords.
—The PC’s return from an adventure with one of the swords, only to run into someone with an identical one, who would understandably like to know their whereabouts.
—A wizard is searching for the secrets to the Forge of Sarvas, in an attempt to recreate the item. He could be rounding up the swords by force to study them and try to reverse engineer them.
Basically anything involving their numerousness—someone could think they have the only one, or know there are many and try to gather them.