Hello-

I cannot find anywhere in the rules that state specifically one way or the other whether casting is audible, or even visual for that matter.

I'm not just talking about obviously visual spells such as firebolt. What about a simple cantrip example. The mage wants to summon a tiny sparrow to distract an enemy. Forgetting whether such a cantrip is legal or not, is there a vocal component to spellcasting that the enemy could hear? This is especially important for my grey mage player who wants to cast some of his less visually-obvious spells without being noticed.

What about priests? Do they have audible spells also?

I've thought about just adding a difficulty die to any spell that he wants to cast silently, but I don't want to punish him if there's no cause. Spellcasting as a rank1 character is hard enough. =)

I've always made it so that while you can cast quietly and subtly, it makes it harder to focus and direct the spell. Rule-wise, I may add misfortune dice to represent this (or make being unnoticed something you can spend boons on).

I also take into account the wind of magic being used. Bright magic is more flashy than Grey.

In agreement I make casting spells "silently" more difficult, and allow sharp eyed characters observation checks, opposed by either stealth, skullduggery or guile depending on the situation.

Crimsonsun