Magical spells in the medieval times requires an incantation and a swing of a wand or quarterstaff to produce any effect, however to cast a high tier grand spell it is necessary to tap the ground as hard as possible with a quarterstaff.
Low tier (hands free) : Generate a short burst of energy at a target. i.e fireball.
Mid tier (hold a wand/staff) : Channeling a constant flow of energy to manipulate the physical properties of multiple targets. i.e alchemy - transmutation of mild iron or bronze into gold etc.
High tier (tapping with staff) : Cast an area of effect spell of great magnitude on every targets within range. i.e disintegration - obliterate all living targets in range into ashes.