Black Sky
Tl;dr Spells have syllables. Stronger spells have more syllables. Runes make casting spells faster, but are hard to make. Each silent cast rune decreases a spell’s casting by one syllable. You can instant cast a spell if your runes are greater than or equal to the spell’s syllables. This is a harder rune to make, so most have less than 3. Each quick cast rune increases spellcasting speed by 10%. Add 10 runes, and your base spellcasting speed increases by 100%. This is linear, not exponential growth. Ex: y= .10x(c) + c where y is your spellcasting speed after runes, x is how many runes you have, and c is your base spellcasting speed. Quick cast runes are easier to make, so most have around 10.
Why is silent and quick cast runes literally the same? Silent should reduce the length of the chant until it was no longer necessary while quick should speed up the chanting speed. Almost half chapter spent explaining a system that makes no fcking sense... What does the multi-cast do then? Reduce cast time by 1% to let you cast move often for "multiple" spells... Using term that are already defined in games/fantasy and then reinventing their meaning for "originality" turning it into an inane BS that makes no sense... How truly promising...