According to the Vivre Card, Roger’s main weapon was a cutlass named Ace, which is one of the 12 Supreme Grade Meito. As one of the 12 Supreme Grade Meito, the quality of Ace’s blade is ranks among the strongest and it is one of the most powerful weapons ever created, rivaled only by a select few other weapons.
Roger frequently imbued the sword with Armament Haki as well as Conqueror’s Haki. Ace was used by the Pirate King during most if not all of his great exploits, until the end of his pirating journey.
Roger was first shown wielding Ace 38 years ago during the God Valley Incident, using it during combat against the Rocks Pirates.
11 years later, during the Battle of Edd War, Roger was shown wielding a flintlock pistol with his right hand and Ace with his left.
A year later, Roger used Ace in combat against his top rival, Whitebeard, in a battle that lasted for four days.
Roger would turn himself in to the Marines to be executed two years following this, and it is unknown what became of Ace.
Between his voyage and death, Roger would sire a son named Ace with Portgas D. Rouge, with Roger having specifically chosen Ace as the name were the child to be a boy. It is not known whether the name of this sword played a part in Roger’s naming decision for his son.