How do you determine the level of a spontaneous spell (in other words, the number you need to roll for success)? Are we supposed to reference the Technique Guidelines? For example, say I want to cast a Crea Animal spell. Do I check the chart on page 116 for a similar effect and use the level given for my spontaneous spell?
Thanks.
Exactly.
And there are two ways to approach it.
The mage can either "do or die", i.e. either reach the level and get the effect, or not, OR (when possible), the effect can be defined as "whatever the roll is", increasing a variable effect or the duration with a better roll.
Example - the maga wants to create a dog*. Either she rolls high enough to achieve the dog, or she doesn't. But if she does, and rolls much higher, it might last longer, or be cast further away - that choice can be made after the roll. (See last par on p 81 thru p 82)
(* Edit: In hindsight, this is an exceptionally high magnitude example for a Spont spell. But let's just go with it.)
What she can't do is, after a good roll, decide she wanted a bear, or ten dogs. The "Basic Effect" has to be the same, but the intensity of it can change.
The short answer is: yes. That's what you do.
You use the same rules as if constructing a formulaic spell (if inventing one). You look at the guidelines and then you add 5 levels* for each step the spell takes on the scales of Range, Duration and Target. You might also have to add levels according to size and requisites. All of this is described in the first pages of the Spell-chapter.
One thing to remember - when casting spontaneous magic the casting total has to double the final spell level, if fatiguing, og 5-double it if not fatiguing. On the other hand spontaneous magic allow something called ceremony where the character gets to add certain academic abilities to the total.
My reply would be use the spell guidelines unless the spell is being cast at a time of high drama and excitement. At those times the GM should tell the players what level the spell is (by making a guess) and then let them roll. You don't want the mundane chore of spell level arithmetic to slow down your game.
Thanks guys, I appreciate your responses. That was helpful.