Based Caster

PREREQUISITE: The ability to cast leveled spells.

When you gain this feat, you can cast spells of 2nd level and higher, using spell slots below its level, to a difference of 3 levels at most.
To cast a spell at a lower level, apply the reverse the At Higher Levels section of the spell an appropriate number of times.   This doesn't apply to any spell that can't be used at higher levels. Additionally, this feat does not allow you to learn higher-level spells than you would normally be able to.   9th-level spells can be "downcast" at Dungeon Master's discretion.   Ex 1. To cast Fireball(a 3rd level spell) at 1st level, you would lower the damage by 2d6, from 8d6 to 6d6.   Ex 2. To cast Ice Beam(a 6th level spell) at 3rd level, you would lower the damage by 3d8, from 8d8 to 5d8.