Warrior's Focus

A crown of golden aura encompasses the head of a single target within reach of the caster. The target is imbued with a magical force that grants the target with increased focus.

For the duration of the spell, when the target makes an attack they have the opportunity to score a critical hit on a roll of 19 or 20.

When cast as a 4th-level spell, the target's weapon attacks score a critical hit on a roll of 18, 19, or 20.
When cast as a 7th-level spell, the target's weapon attacks score a critical hit on a roll of 17, 18, 19, or 20.
When cast as a 9th-level spell, the target's weapon attacks score a critical hit on a roll of 16, 17, 18, 19, or 20.