I wrote up a short example of how the PeVi spell Break The Shield works against Parma Magica in a forum thread. It’s not my favourite spell in the raw (see grumble below), but it is legitimate in the rules so knowing how to play it out is handy.
A quick example of Break the Shield (a.k.a BtS, published in Hermetic Projects, p.85) in use by two magi against each other might be:
Magus Alphar (BtS PeVi15, Pe5, Vi5, Stm3, Pen 0, Parma 2) vs. Magus Betar (BtS PeVi15, Pe10, Vi12, Stm3, Pen 0, Parma 1)
- Due to the randomness of initiative Alphar casts BtS against his opponent Betar first,
- Alphar’s BtS PeVi15, CT is 13+roll. He scores CT:20, which is Level 15 with +5 Pen.
- Betar’s MR is equal to Parma (1*5) + Vim 12 = 17. This means the spell fails to penetrate. There is no need to roll the Level + dice to cancel the spell.
- Betar returns the same BtS PeVi15 spell, with CT is 25+roll. She scores CT:32, which is Level 15 with +17 Pen
- Alphar’s MR is equal to Parma (2*5) + Vim 5 = 15. This means that Betar’s spell has penetrated successfully, so now the test of (spell level + roll)/5 vs PM score must be checked.
- Betar rolls Level 15 +roll, gets a total of 19. This total divided by 5 exceeds is 3.8, which is higher than Alphar’s Parma Magica score of 2, so down goes his Parma Magica.
- the next round might be ugly for Alphar…
This demonstrates why low level PeVi spells are handy against supernatural creatures i might stripping, and also why having several Break the Shield Spells might be useful, or investing in mastery and penetration is important for BtS.
Aside – My grumble about Break the Shield is that it reduces the influence of Parma Magica in the game setting, which in turn was a major justification for the successful formation of the Order of Hermes.
If BtS was available then why was PM a successful bargaining point. Having BtS in the game also creates an escalation in PM stripping spells as an opening volley. The first magus specialises in stripping parma and then proceeds to decimate the target. Every Magus beyond their mid years should learn the spell and master it using the defense mastery so that they can try to resist it.