Mana Burn
Mana Burn (Sp)
Beginning at 3rd level, you can push structured portions of your aura into the casting of a spell, mixing of an extract, or brewing of a poultice, burning up one or more additional spells, extracts, or poultices as part of the casting action of the spell being cast. These additional spells cannot be cantrips (or orisons, or powerful cantrips), but can be any other spell, extract, or poultice you have memorized, or spell, extract or poultice slot you have available.
For purposes of mana burning, spells, extracts, and poultices are equivalent, and may be exchanged freely, and any time a 'spell' is referred to in these rules, it applies to any or all of these three types. If you are multi-classed or dual classed or other wise have access to spells, extracts, and/or poultices, any of them may be burned to boost any of the others.
Burned spells are used up for the day, exactly as though they had been cast. For each additional spell you burn in the casting, you increase the spell's Circle by one step, increasing the spell's base damage dealt.
A spell's Circle is a measure of how much base damage it does, relative to the caster's character level. If a spell has a Circle listed, it will be highlighted in orange in the spell's description. Aside from certain arcane bloodlines and certain expensive magic items, the only way to increase a spell's Circle is by mana burning one or more additional spells at the same time that the spell is being cast (as part of the same action). For each extra spell burned, the spell's circle moves up one step on the damage scale.
There is also a maximum spell circle you can raise a given spell, based on your character level. This maximum is: (total character level + 1) ÷ 2, round down. Note that this is NOT based on the character's caster level or class level, but their total character level, making this an attractive option for multi-classed or dual-classed characters. Furthermore, the maximum is unaffected by classes who learn higher level spell slots at a slower pace than full casters. For example, even though a bard cannot cast 3rd level spells at 5th level, they can cast a 2nd level spell and mana burn it to Circle 3 damage, dealing the equivalent of a third level spell.