You call down a minor portent upon yourself from the stars, opening up possible outcomes for yourself within the next few minutes.

Until the spell ends, you can use a reaction when you make an ability check, attack roll, or saving throw to force a roll of 19 on the d20. You may do so after seeing the roll, but before the outcome is determined. The spell then ends.

Alternatively, when a creature you can see makes an attack roll against you or is forced to make a saving throw by one of your spells or abilities, you can use your reaction to force that creature to roll a 2 on the d20. The spell then ends.

If you cast this spell two or more times before completing your next long rest, there is a 50 percent chance with each casting that you will force the opposite roll of what is desired (forcing yourself to roll a 2, or another creature to roll a 19).