When you want to cast a spell, you must draw upon the power of the Winds of Magic and focus it into your desired effect (the chosen spell). To do this take the cast action and then roll a number of d10s equal to your Magic Characteristic. Now total the dice. This is your Casting Roll. If the result is equal to or greater than the spell’s Casting Number, it is cast successfully. You may roll a number of d10s less than your Magic Characteristic if you want to (and indeed, it’s often a good idea). Casting is often an extended action, which means you must continue casting a spell until it’s finished. As per the normal rules, you may abort the spell part way through, but this means all actions taken thus far are wasted.

Example: Altronia, an Elf Master Wizard, attempts to cast the fiery blast spell, which takes a half action. With a Magic Characteristic of 3, she can roll up to 3d10 to cast a spell. Since the fiery blast has a high Casting Number (21), she opts to roll all her dice. Her Casting Roll is 7+7+7=21. This equals Casting Number and so the spell is cast successfully.

Channelling and Ingredients
There are two ways you can increase your chances of casting a spell. First, you can make a Channelling Skill Test right before the spell is cast. Doing so is a half action. Channelling helps you focus the energy of the Winds of Magic. If the test is successful, you add a bonus equal to your Magic Characteristic to your Casting Roll. If you use Channelling, casting a spell must be your next action.
  Your other option is to use special ingredients. If you have the correct ingredient, it provides a bonus of +1 to +3 to your Casting Roll. An ingredient is only good for one casting of a spell and you must decide to use it before you make your Casting Roll. The availability of ingredients can vary depending on your location and the nature of the item, but generally speaking ingredients that provide a +1 bonus are Common, a +2 bonus are Scarce, and a +3 bonus are Rare. The more esoteric ingredients can’t be found in any shop and must be acquired personally, often at great risk.

Example: Heinz, a Journeyman Wizard, is trying to cast the spell earth gate. With Magic 2, Heinz wants to increase his chances of casting the spell. First, he spends a half action to make a Channelling Test. If he succeeds, he’ll gain +2 on his Casting Roll. Unfortunately, Heinz fails his test but all is not lost, as he has also decided to use an ingredient. He pulls out an iron key, the ingredient for the earth gate spell, and uses it during the spellcasting. This gives him a +2 bonus. His Casting Roll is 12. Normally, this would have been a failure, but with his +2 the Casting Roll becomes a 14 (earth gate’s Casting Number) and he successfully casts the spell.

Automatic failure
When magic is involved, nothing is certain. Regardless of a spell’s Casting Number, if all the d10s of your Casting Roll come up 1, the spell fails. In addition, you must take a Will Power Test or gain an Insanity Point as the uncontrolled magical energy sears your mind. Because they only roll 1d10 to begin with, novice spellcasters are in greater danger than their more experienced elders.

Example: Horst, a Hedge Wizard with a Magic Characteristic of 1, is tired of studying in the sputtering light of a candle so he decides to cast the magic flame spell. He makes a Casting Roll with his 1d10 and gets a 1, so the spell fails. He then makes a Will Power Test, fails it, and so gains 1 Insanity Point. Horst learns a valuable lesson about using magic for trivial purposes.