Another way of limiting the extreme complexities possible through Thaumaturgy (without risking to fail if the Wizard have Discipline 5 or more) is by saying that every time you pour power into the spell, it takes one step on the “Time Increment” table (instead of one Exchange).

If you have Discipline 5, you can pour one shift of power into the ritual safely (without risk of failing). This means that one day is equivalent of 11 steps, which is the same as to say that a Wizard with Discipline 5, in case he wants to be 100% sure not to fail the ritual, it takes one day. Complexity 13 thus takes one week, and complexity 15 takes one month. Now were talking! If you want to add more than one shift of power every time, you can aim for higher complexities (or faster results), but you risk of failing the ritual.

If you have Discipline 6, you can pour two shifts of power into the ritual safely (without risk of failing), meaning that this Wizard can pour 22 shifts in to a Ritual in one day (i.e. 11 times, using the “Time Increment” table) without having to roll the dice. If he is aiming for a higher complexity or faster results, he will have to pour more than 2 shifts of power in to the ritual (and thus risk of failing the roll).

What do you think about that?