Amulet of Thusia

This broach is a white pearl carved into the shape of an eye and etched with black ink. The pupil comprises a spiral that appears to loop inwards without end.

You gain the ability to draw on the latent luck in the world around you. Once per day, before you make an attack roll, an ability check, or a saving throw, you can roll an additional d20 and choose which of the d20s to use. Alternatively, before an attack roll is made against you, you can force the creature to roll a second d20 and use the lower result.

If the original d20 roll has advantage or disadvantage already, you roll the additional d20 after advantage or disadvantage has been applied to the original roll.

Once the item has been used in either of these ways, it can't be used again until you complete a long rest.