The following are various optional rules for the Conan RPG by Mongoose Publishing:
Desperate Blast (replaces Defensive Blast)
The purpose of this variant is twofold. First, to make Defensive Blast more like it was intended (as a last-resort defense tactic, not as an offensive fireball-like attack). Second, to make the visible effect more dark and sinister, keeping with the swords & sorcery feel of the Hyborian Age.
Thanks to SableWyvern for useful ideas on some of the effects.
Defensive Blast is renamed Desperate Blast. A Desperate Blast is not a fireball. It is a last-resort tactic for the sorcerer, invoking dark forces the sorcerer can barely control. Desperate Blast can only be used once per day. It uses up all of the sorcerer's remaining Power Points. Using Desperate Blast is a free action. It can be used as an attack of opportunity or as a readied action. Desperate Blast affects all creatures within a 10 foot radius. It does not affect the sorcerer himself. Scholars who do not know any sorcery styles or advanced spells, or non-scholars with the Dabbler feat, cannot use Desperate Blast.
A scholar who unleashes a Desperate Blast must roll a Concentration check (DC 15). The sorcerer cannot take 10 or 20 on this check. Success means the sorcerer can select the specific effect from the list below. Failure means that the specific effect is determined randomly (1d8):
All effects cause 1d6 points of damage of the specified type per Power Point expended. Targets get a Fortitude save for half damage. The sorcerer sets the DC of the saving throw using his magic attack roll. All effects, regard of type, can cause Massive Damage saves if the attack inflicts 20 or more points of damage. Note that if the sorcerer has the Opportunistic Sacrifice feat, he may be able to regain Power Points from slain targets, if any. He is still limited to one use of Desperate Blast per day.
Another Variant: At the DM's option, the Concentration check DC can be set equal to the number of Power Points expended. This makes it more difficult to control the exact effect of the blast as the number of damage dice increases.