Silver Sword of Gith

The Silver Sword of Gith is an artifact sacred to the Githyanki. It was the first and most powerful of the githyanki silver swords and belonged to the Githyanki hero Gith. When Gith left her people to seek an alliance with Tiamat and never returned, the sword was lost.

Description
The Sword of Gith is a jagged-edged scimitar-like greatsword with a silver blade and golden hilt.

Forgotten Realms: Demon Stone
The sword is central to the plot of Forgotten Realms: Demon Stone, though the player does not find out why until the end of the game. The Slaad lord Ygorl desired the artifact to increase his own power. At the time, the sword was in the hands of Cireka, a Githyanki general. The two battled over it, pitting their armies against each other until their fight spilled over into Toril and Khelben Arunsun trapped them in a magical stone. When adventurers release the two, their fight resumes until Cireka is slain by the red dragon Caminus. Rannek of Nesmé retrieves the blade and uses it to help defeat Ygorl. He is concerned however, that the Githyanki will return to retrieve it at some point.

Neverwinter Nights 2
The Neverwinter Nights 2 games expanded on the sword's history considerably, establishing that the sword was originally forged for Gith by Zerthimon. Ammon Jerro found the artifact but when he attacked the King of Shadows with it, it shattered into several shards, one of which buried itself inside the body of a baby who would grow up to be the Kalach-Cha. The Kalach-Cha collected the scattered shards, whilst being pursued by the zealous Githyanki, and eventually reassembled them at the site where the blade originally shattered.

The sword gained a couple of new powers due to the fractured nature of the blade, but since the final shard was still buried in the Kalach-Cha's chest, it could not be fully restored. The nevertheless powerful blade was then used to defeat the King of Shadows.

The blade was established in the game as the only weapon powerful enough to defeat the ancient, corrupted Guardian of Illefarn. The warlock Ammon Jerro, learned of the weapon from his dealings with the Githyanki, devils, and an ancient crystal dragon named Nolalothcaragascint.

It is unknown whether the Lich Queen is aware of the importance of the Sword to the Githyanki religion and culture, though the Githzerai certainly are. It was also unknown if the Githyanki will try to retake the blade, given that their mightiest sword stalker, Zeeaire, has already been slain by the Shard-Bearer. They also possibly understand that to take the sword would mean to lay siege to Crossroad Keep, the stronghold of the Shard-Bearer, and a citadel that is clearly one of the best-defended on the Sword Coast.

Neverwinter Nights 2: Mask of the Betrayer
The history of the Sword of Gith is further expanded in this game. It turns out that the sword, in addition to being an outsider-slayer of unimaginable power, is the key to the Betrayer's Gate, a portal to the Fugue Plane located in a temple to Myrkul on the Plane of Shadow in Mulsantir. This Gate was used by Akachi the Betrayer, a former priest of Myrkul, who used the blade to try and destroy the Wall of the Faithless and free his dead love, a Red Wizard. After the player was abducted into the land of Rashemen by the Founder after they vanquished the King of Shadows, the prime shard that was buried in their chest, was torn from them violently, the Founder then used that last piece of the sword, and cast it back into the whole, strengthening the weapon even further, though the blade retained it's previous nature of servitude to the Shard-Bearer who reforged it. The Founder then explained her reason for choosing the Shard-Bearer to defeat the spirit eater, "Because you had the will to master the Blade of Gith." After regaining the Blade, the Shard-Bearer then had the option of killing the Founder for afflicting them with the curse, whether or not they her, the Shard-bearer then uses the weapon to open the Betrayer's Gate. When they've reached the Fugue Plane and Kelemvor's Gray City, the Kalach-Cha will then be given the choice, of leading Akachi's generals to lay siege against the City, or defending it against them. (It should be noted that Akachi's generals were a Fallen Angel, a Blue Dragon and a Demilich, thus all of them were of questionable alignment). Despite whatever the Kalach-Cha decides, the Lord of the Dead, Kelemvor, (appearing for the first time in an Forgotten Realms RPG) will arrive, and allow the Shard-Bearer to claim their soul from the Wall of the Faithless, where the Founder and Akachi once were, the Shard-Bearer must then battle the avatar of the Spirit-Eater curse for control of their own soul. Eventually, after battling the Spirit-Eater curse across dreamscape versions of Crossroad Keep and West Harbor, the Kalach-Cha corners the Avatar and uses the Silver Sword to defeat him. What happens afterwords depends on the player's actions or whether they were able to find the pieces of Akachi's Mask of the Betrayer.

It is unknown what became of the Sword following the Kalach-Cha's victory in the Fugue Plane; it is likely they still wield it.