This is essentially a Dimicatio, with the exception that each match lasts until one combatant scores three "touches" against his opponent.
You will cast spells at your opponent forcelessly (0 Penetration-- you can always opt to drop your penetration on any casting down to 0 with no penalty for doing so). Your opponent tries to fast-cast a defense. Each time someone fails to fast-cast a defense, their opponent scores a point. It is three points to win a match. Generally speaking, the bigger the offensive spell, the harder it is to fast-cast a defense.
Rules for fast-casting are on p.83. Common fast-cast defense options: either negate or redirect the magic itself (Perdo or Rego Vim), move out of the way of the spell (ReCo), or directly oppose the form of the spell itself (someone throws a rock at you with ReTe, you could PeTe to destroy the rock).
The very first match is Focus Flambonis vs. Gavril Tremeris; Focus destroys Gavril in a single round, as he multicasts five Balls of Abysmal Flame in rapid succession. Gavril uses Muto Ignem with an Animal requisite to turn the first fireball into a fluffy bunny, a Muto Vim with an Imaginem requisite to turn the second fireball into a harmless flash of light, and then he takes three fireballs to the face and is eliminated.
Use invisible castle to roll your own dice for these matches.
Group Phase, initiatives:
** Iapetus 7, Zan 5
Iapetus must cast a spell at Zan, with 0 penetration. Zan will try to fast-cast a defense against it, and return fire.
** Sinmore 2, Deiectus 4
Deiectus opens with a Ball of Abysmal Flame.