Once you have all the necessary ingredients, you can cast your spell. You do this as an action during the Encounter Step in the Evening phase. Your target is chosen during the Melee Step. If your time is less than or equal to the times of all the monsters/chits on your sheet your spell works! However if someone targets you with a spell, your time has to be less than their spells time.
If your worried about your time number not being fast enough. You can Alert the spell chit during the day, in which case the time number becomes 0.
If the spell was an attack spell, you then use the chit just like a fight chit to determine if you hit your targets.
The first spell phase is not used for anything (called the SPX phase in the second edition rules). During that phase your player is meditating, getting ready to perform a useful spell phase. Note you don't have to do this in order to actually cast a spell at the end of a day.
Any spell phase recorded after the first can be used for one of two things:
While talking to the Company he finds they have the BEAST PIPES so he buys them. This gives him a Magic VIII chit with a time number of 0. However the chit can only be used with the spell in the item.
He spends a search phase (or several search phases) trying the read the runes on the pipes and finally awakens the spell. It turns out to be BAD LUCK. He now has a spell and a chit, all he needs is the right color.
He looks up bad luck and finds that any color will do to cast this spell. This means he can cast it whenever it's Sunday (and color magic is supplied to the whole board), he can cast it in any enchanted tile, at the Church (where White magic is supplied), or if he is in the same clearing with any Treasure that supplies color magic.
While walking through some enchanted woods, he comes across the Elf. The Elf has already killed two players and blocks the Black Knight. The Black Knight can't run and considering the Elfs Archer ability is in sorry straights. One thing the Black Knight can do is to use the Beast Pipes (Magic VIII 0 chit), and the Gold color (from the enchanted tile), to cast his Bad Luck spell on the Elf. This will go a long way toward helping the Black Knight win the fight and might even encourage the Elf to run away himself!
After a fierce battle with some goblins, he finds himself with very few chits active and his armor damaged. He now wants to cast his spell to fix his armor and rest all his chits quickly.
He has the spell and a chit to cast it with but he needs the color. Two spell phases will allow him to turn his Magic chit into a color chit but then he won't be able to use it's ritual type to cast the spell! So he must find the color elsewhere.
Fortunately, the Chapel is near by so he goes there and now has a source of White Color to power his spell. Note, the Sacred Grail and the first Sunday of the month also supply the color he needs.
If he had found the Sacred Statue and read the runes on it to awaken it's spell, he could use a spell phase to Enchant his Magic Chit. Then he would have the Statue for the Ritual Type, his enchanted chit for the color, and the spell in the statue to cast.
He finds the Crystal Ball but the clearing is getting rather dangerous. He really doesn't want to stay here but he can't pick-up the ball (something about being non-corporeal :-)
He wants to cast his unleash power spell so he can pick up the ball and take it somewhere safer. He has the spell, and a type VI magic chit but where will the color come from?
During the day he spends a spell phase to meditate, then another to enchant a type IV magic chit into Purple Magic. That evening he casts the spell on his MAGIC V4* chit (note you must cast Unleash Power on a chit). The next day, he can use the unleashed power in the MAGIC V4* chit to pick up the ball and move off.