Some spells or abilities require the player to tap a permanent as part of their cost.

"Not all Adept spells require such a thing," he corrected.

Some spells also require the payment of additional resources, such as cards in play or life points.

Her spell was ready and only required her to touch the man on any bare skin.

The spell requires three trials be performed by one person.

Many spells required something of the target in order to be launched; had these men left articles behind that were now being used against them?

The spell would require only a small amount of energy.

One spell requires the head of a dead baby, which seems to speak.

And he knew, as they raced together, that some spells require nothing more than a willing heart.

Real spells for it are a lot more complex and usually require a human sacrifice.