After losing his lightsaber in a duel with Darth Vader in the bowels of Cloud City, Luke Skywalker retreated to Ben Kenobi's hut in Tatooine's Jundland Wastes.
More information about the weapon available on the Wookieepedia article.
LUKE SKYWALKER'S LIGHTSABER[1][]
Return of the Jedi: When the wielder uses Luke Skywalker's Lightsaber and the Reflect talent to decrease damage from a ranged attack, the wielder may spend a Destiny Point to allow all allies in the encounter to decrease the difficulty of any Discipline checks they make for the remainder of the encounter by 3, to a minimum of Simple difficulty.
SON OF SKYWALKER[]
[...] Whenever Luke wields his lightsaber and spends a Destiny Point to upgrade the ability of a check or the difficulty of a combat check targeting him, he upgrades it twice instead of once.
- ↑ Gadgets and Gear: The Essential Collection of Weapons and Equipment (Page 49)