Blast everything nearby with an explosion of elemental magic.

Affects all other creatures in a 15 ft. cube centered on you.
Intensify: You may add +10 ft. to the length of the cube’s sides per boost from Intensify.
Friendly Fire:
You can try a DC 15 test of Spellcraft to exclude a target from being affected by your spell.

All creatures in the area get a health (reflex*) save.

Fail:
The target takes 1d12 elemental damage
Intensify: +1d12 elemental damage per boost from Intensify,
and is pushed 5 ft. away, regardless of size.

(If the target would be pushed into a mortal hazard which would cause it to instantly or imminently die, such as off a cliff, it gets a health save to avoid being moved into that hazard, but is still moved as far as safely possible.
Being pushed does not provoke attacks of opportunity.)

Pass:
The target takes half as much damage, and is not pushed.

Suggested Backfire: The spell blows up in your face. You take the full damage unless you pass a health save to half it. Noone else is affected.

*If you cast this spell with the poison or dark element, the save against this spell is a health save.
Otherwise the save against this spell is a health (reflex) save.
Certain abilities interact with health (reflex) saves.

You overcharge your Arcane Burst spell, dramatically increasing its power.
Creatures have disadvantage on their saves against your Arcane Burst.
Add up to +30 ft. to length of the sides of the cube of your Arcane Burst’s area.

Any creature which fails its save against your Arcane Burst is pushed out of the spell’s area.
For every size bigger than medium the target is, it is pushed 5 ft. less.
(Relevant Sizes: Medium, Large, Huge, Giant)

(If the target would be pushed into a mortal hazard which would cause it to instantly or imminently die, such as off a cliff, it gets a health save to avoid being moved into that hazard, but is still moved as far as safely possible.
Being pushed does not provoke attacks of opportunity.)