Source: The Book of Many Things

Armor (heavy), very rare (requires attunement)

The outside surface and internal joints of this armor whir with interlocking gears, drawing on the orderly magic of the plane of Mechanus.

The armor has 4 charges. If you make a d20 roll while wearing this armor, you can expend 1 charge to change the number rolled to a 10. The armor regains 1d4 expended charges daily at dawn.