As I covered in a previous post, Ars Magica contains a subsystem for magical dueling, called certamen, that is the focus for my current magus character. The supplement Houses of Hermes: True Lineages contains additional rules for certamen, including specialized styles (also called schools). The styles are a great addition to the core certamen rules as they create more interesting strategic and tactical options while establishing additional lore and flavor.
Unfortunately, not all schools are equal. This in itself is not an insurmountable problem, but the issues with the schools are compounded by the two-tiered system of proficiency for each school. One season of study allows a maga to fight "in the style" of a school, with dramatically reduced benefits. Two seasons of study are required for full mastery. At the start of any given duel, a maga chooses to either fight as a follower of a specific school or to duel in a variety of styles using only the lesser benefits.
In practice, players almost never opt to duel in a variety of styles because the ostensible benefits for doing so are often punitive. This is a shame, because the idea of two master duelists shifting between styles mid-duel is fantastic and could lead to great tactical decisions from round to round -- something that is lacking in the certamen RAW.
I do not think fixing these problems requires a dramatic change to the RAW and I propose the following remedies for both individual schools and for the system as a whole:
Certamen Reputations - Instead of using the table on page 134 of HoH:TL, roll a stressed Intelligence + Order of Hermes Lore + Duelist Reputation on this table (use the modifiers table on 134, though):
3 - Scandalous breaches of etiquette.
6 - Famous victories and victory spells.
9 - Famous losses.
12 - Favored schools.
15 - Strong arts.
18 - Moderate arts.
21 - Weaknesses.
A botch always results in misinformation of some sort. Minor botches get favored schools wrong. More serious botches get the arts and weaknesses badly mixed up.
Harenarius Virtue - RAW, but the Master Duelist reputation is for the entire Order of Hermes instead of just Tremere.
Master and Follower Benefits - If a duelist has spent two seasons studying a school, she is considered a master and gets the full listed benefits for that school. If a duelist has spent one season studying the school, she is considered a follower and takes a -1 penalty to Attack, Defense, Weakening, and Resistance totals and 1 additional botch die when fighting in that style. Otherwise the maga uses the full listed benefits as a master.
As in the RAW, most magi can only master a single school of certamen (excepting those with the Harenarius virtue), but could conceivably become a follower of many.
Starting School - By default, all magi begin as followers of Gladiator, for free. Special circumstances may justify individual magi starting as a follower of another school, which replaces Gladiator.
Dedicated or Shifting Styles - At the beginning of certamen, the maga may choose to fight dedicated to a single style or opt for shifting styles. If she fights dedicated to a single style, she uses the rules as written. If she chooses to fight with shifting styles, she suffers a -1 penalty to all Attack and Defense totals and rolls 1 additional botch die for the entire duel. These penalties are cumulative, so someone dueling in shifting styles as a follower would have -2 to Attack and Defense totals, -1 to Weakening and Resistance Totals, and 2 extra botch dice.
School Adjustments - The following adjustments are intended to make a wider variety of schools appealing for use in certamen, especially Gladiator (Ars Magica's "default" certamen style), and several other schools that had less valuable advantages overall.
Gladiator - Fighting as a master of Gladiator gives +1 to Attack, Defense, Weakening, and Resistance totals and subtracts 1 botch die. A standard maga with no additional school training will typically duel as a dedicated follower of Gladiator, negating all of the listed benefits.
Andabatus - In addition to the listed RAW benefits, masters of Andabatus always have +2 on their Weakening totals and -1 on their Resistance totals.
Bestarius - These rules replace the Bestarius RAW entirely. Masters of Bestarius can project their Heartbeast into the shared illusion to intimidate and unsettle their opponent. On a successful attack, a master of Bestarius may decline to do damage. Instead, their opponent must roll a stressed Stamina + Concentration against an Ease Factor of half the Bestarius' Heartbeast score (rounded up) +2 for every level of Fatigue declined. If the opponent fails, the Bestiarus may reduce their opponent's Weakening or Resistance total by the Bjornaer's Heartbeast score. This penalty lasts until after the resolution of the Bjornaer's next attack.
Bone-Biting - Like the RAW "fighting in the style" rules, but the Attack Total bonus for a Light Wound is +13. As there are no masters of Bone-Biting left (or are there...? oOoOoOoOh!), a follower of Bone-Biting would typically inflict a Light Wound and have +12 Attack, -1 Defense, Weakening, and Resistance with 1 additional botch die on top of other modifiers. As in RAW, the Bone-Biter may sacrifice a Light Wound to absorb the next two fatigue levels they would have lost in the duel.
Charon - The RAW still exist as a "trick". However, here are some rules for them as a school. The Charon style focuses on feinting against the opponent. Their portion of the shared illusion contains duplicate images and subtle perspective tricks layered over each other. On any given round, they may choose to sacrifice up to their Finesse to feint on either Attack or Defense. If the feint roll fails by the penalty or if it succeeds in spite of the penalty, the duelist may immediately re-roll and add the penalty.
Essedarius - Similar to RAW, but the check is Stamina + Concentration against an Ease Factor of 5 + 2 per Fatigue level the Essedarius has declined to inflict during certamen. The check is made each time the Essedarius declines and the penalty is -2 to Attack and Defense totals and 2 additional botch dice. The penalties are cumulative and last until the end of combat. Many opponents eventually surrender out of fear that they will enter Twilight through a botch.
Gladiatrix - The Gladiatrix may decline damage to attempt a reading of the opponent's vulnerabilities. The opponent must roll Intelligence + Concentration against an Ease Factor of 5 + 2 per fatigue level the Gladiatrix chooses to decline on that specific attack. The Gladiatrix may choose to learn the score of any of their opponent's Arts, one of their characteristics, all their personality traits, or the score and specialization of Concentration, Finesse, Parma Magica, or Penetration. If they choose to learn the score of an Art that is being used in the duel, the opponent suffers a -3 penalty when using that Art for the remainder of the duel. If they choose to learn the score of one of the abilities, that ability suffers a -2 penalty for the remainder of the duel.
Some Gladiatrices have a bad reputation for toying with opponents or using duels "for love" as a means of ferreting out weaknesses in advance of a duel with serious consequences. Many duelists have argued that Gladiatrices are magically scrying, but no tribunal has ever made a ruling equating it as such.
Hoplomachus - RAW.
Laquerius - RAW.
Provocator - RAW.
Pumilius - Similar to RAW, but the check is Intelligence + Concentration against an Ease Factor of 5 + 2 per Fatigue level the Pumilius declines. If the duelist knows personality traits of the opponent, each one can be used once per duel for a bonus to the Ease Factor equal to its absolute value. If the maga fails her Concentration roll, the Pumilius can reduce her next Attack or Defense roll by 15.
Retiarius - A different approach from RAW but conceptually similar to the swift-striking Fishermen. A master of Retiarius can attack twice in a round at a -3 penalty to both Attack Totals.
Saggitarius - RAW.
Scissor - Masters of the School of Carvers sacrifice up to their Finesse on Attack Totals, but if they hit, they increase the Weakening Total by twice the penalty.
Velitus - RAW.