In yesterday's post about scrolls, I described my personal vision of little tiny scrolls with wax seals. There's a two-word magic phrase written on the outside (Yes, I was thinking of this when I came up with the random scroll labels idea.) To activate the scroll's spell, the caster recites the magic words while breaking the seal; the whole thing can be done with one hand, in contrast to the way many other FRPGs describe scrolls. If the seal is broken, but no words (or the wrong words) are recited, the scroll is wasted. If the words are read aloud without breaking the seal, nothing happens.
But there's more to it than that. The way I figure it, scroll spells are aimed or controlled by various gestures and changes of tone. The standard gesture is to hold the scroll at arm's length in the direction of the target; this works for single-target offensive spells. Casters who wish to target themselves can hold the scroll across their chest instead.
Some spells create barriers instead. Holding the scroll crossways horizontal to the floor creates a barrier in the direction of the caster's arm, parallel to the scroll. Holding the scroll above your head creates a barrier above; pointing it straight up and making a circular gesture creates a ring-shaped barrier around the caster.
Some spells target multiple individuals. Whispering the magic words limits the spell to those who can hear the caster. Merely speaking the words with a normal voice affects all within a short distance, but any direction. Shouting the magic words affects those directly in front of the caster, but at a greater distance.
I wonder if it would be worth it to work up other gesture and intonation effects. What if the caster recites the magic words as if they were a question? What if the first word is shouted and the second whispered, or vice versa?