It is well-known that House Tremere excel in the use of Certámen, the Hermetic method of resolving disputes. It cannot be through mere practice that the Tremere have got so good.
Listed here are a number of tricks used by House Tremere to get an edge in Certámen. They are all named after particular combat moves. They are only taught by House Tremere, and never to outsiders. Most members of the Order are unaware that these tricks exist - they were developments of the theory of certámen devised by Tremere and Quaertus, Bonisagus's first apprentice, but largely invented by Tremere and never entering the corpus of knowledge about the technique.
The tricks are listed in ascending order of difficulty. To learn each trick, a minimum level of the Certámen skill is required, as listed below. One also needs a teacher who is prepared to impart these skills to a pupil - a parens will never teach these skills to a former apprentice, else it would be too easy for them to win their sigil, thus it is very rare for a magus to start the game with one of these skills. Members of House Tremere must seek out another mentor within the House, who will often demand payment in the form of political support, with perhaps the use of the pupil's sigils for a period of three, seven or nine years. Once payment as been settled, the pupil must devote time with his or her mentor, learning the certámen trick. This counts as gaining experience points through Training (p. 187 of the Ars Magica rulebook), and the same rules apply - the master must have a score in certámen of at least three levels higher than the pupil. This season of training is not exclusive - both pupil and master can spend time doing other things, but at least one day a week must be dedicated to training, resulting in -3 to all lab totals. Frequently, the pupil wastes an entire season in this training, because they have had to travel to the covenant of the master, where they have no laboratory to work in. Training a apupil like this can also gain the master experience points, accoring to the Practice Rules (p. 187 of the Ars Magica rulebook).
Once the pupil has accumulated experience points equal to the minimum certámen score for the technique, then they have learnt it. For example, to learn Riposte which requires a minimum Certámen score of 5, they must accumulate 5 experience points.
Characters who have faced Tremere using these techniques in certámen, or who have watched a duel in which they are used, can anticipate the attacks if used against themselves. They can be identified with a Per + Certámen of 9+, 12+ if the magus is currently engaged in a duel. Tremere need not roll to spot techniques that they know themselves, but must roll to spot other tricks. Those who have never seen them in use will probably fall to them easily.
Note that only one trick can be used in any given round of Certámen except Shield, which can always be used. Note that the Attack bonus referred to below is the Int + Certámen + Technique + Form + Carry-over Advantage made by both opponents; the Weaken roll is the Int + Certámen + Advantage; and the Soak roll is the Sta + Certámen toal.
Minimum Name and description
Certámen
2 Shield: This trick allows the Tremere to fashion a
phantasmal shield to sap the strength of their opponent's
attack. They may subtract a number of points less than or
equal to their Certámen score from their Attack bonus each
round to add to their Soak total.
2 Drive: If the Tremere gains an advantage in an attack, he
may add two to the attack in the subsequent round regardless
of whether he uses the advantage as a carry-over bonus or
attempts to weaken his opponent.
3 Desperate Defence: By using this trick a Tremere can elect
to lose a Body Level instead of a Fatigue Level. Only one
Fatigue Level can be exchanged in this way in any round, but
this may be enough to prevent the Tremere from going
unconscious.
4 Great Blow: before making an attack roll, a Tremere can
subtract points up to twice his Certámen score. If the
attack is still successful, he gets a bonus to his Weaken
total equal to 1½x the points he subtracted from his attack
(round down). Thus he sacrifices skill for power.
5 Riposte: By foregoing an attempt to weaken an opponent after
an advantage is gained, a Tremere can attempt to redouble
his next attack roll. He must make an Int + Certámen stress
roll with an ease factor equal to 3 + half the advantage he
already has. If this riposte roll is successful, he can add
the amount by which he made the riposte roll to his next
Attack total, in addition to the advantage initially gained.
If the riposte roll fails, his carry-over advantage becomes
zero.
6 Feint: the Tremere makes two attacks. The first uses his
Technique and Form total plus any carry-over advantage and a
stress die; the second just uses his Int + Certámen total,
with no die roll. Both attacks must attempt to weaken his
opponent. If this opponent fails to notice the second sneak
attack (Per + Certámen, as detailed above), it goes
unopposed, and the opponent must apply his Soak total to
this second attack as well. If the sneak attack is noticed,
the it fails automatically. Note that the first attack does
not need to be successful for the second attack to succeed.
7 Pummel: When making a roll to weaken his opponent, a Tremere
can split the Weaken total into a number of attacks less
than or equal to his Certámen score. For example a weaken
bonus of +12 (Certámen 7) can be split into 4 attacks of +3
each; or 5 attacks of +2 and 2 attacks of +1. Each one has a
stress die added to it, and is compared against the Soak
total of the opponent (make one roll, and apply to all
attacks). This multiplicity of attacks can weaken an
opponent rapidly. However, should the Tremere using pummel
botch any one of his rolls to weaken, he gains a number of
botch die equal to the number of Weaken rolls made.
8 Main Gauche: This trick is an enhanced version of the Feint
trick. The whole Attack bonus of the Tremere can be split
into two, which may or may not be of equal size. A stress
die is added to each. A Tremere who knows this trick can
divide his own attack bonus to face each attack against him,
otherwise the opponent has to choose which attack to defend
against (assume that he has seen both, see above). The
advantages gained from both attacks are added together to
determine the strength of any attempt to weaken, or to work
out the carry-over advantage.