Oracle (5e Feat)
From D&D Wiki
When you finish a long rest, roll two d20 and record the numbers rolled. You can replace any attack roll, saving throw, or ability check made by you or a creature that you can see with one of these foretelling rolls. You must choose to do so before the roll, and you can replace a roll in this way only once per turn. Each foretelling roll can be used only once. When you finish a long rest, you lose any unused foretelling rolls.