Unskilled Magic is basically an off-the-cuff system, but a pretty limited one. To quote the book...
Unskilled Magic. You may simply announce the spell effect you’re trying to produce and dump Mana into it.
- Whatever-it-is you’re trying to do will cost 2 Mana per level of the effect - half of which is wasted and a quarter of which goes into random side effects.
- The Casting Level equals the user’s level or (Int/3 + the effect level), whichever is less.
- The maximum level of effect which can be produced quals the user’s base Will save bonus or (Wis/3), whichever is less.
- Keeping the side effects down to displays and inconvenient effects (rather than dangerous ones) requires a Cha check at a DC of ([2x the Mana used] + 6). The side effects are always up to the Game Master.
Khorolf likely doesn't care if he blows up a little or (knowing him) has purchased some way to roll strength instead of charisma as he bludgeons the magic into submission or some such.
So good to have in your back pocket, and a good way to get some special-purpose boosts, but it will quickly fall behind people who actually know what they're doing (if only because you're spending four times as much magic on any effect as a skilled caster would). Still, he did hand it out all around, so if you want to try a trick or two, why not?