Fast casting against another wizard in Ars Magica

One of those forum conversations that leads into a brief explanation of how the game mechanics resolve magic… The Mirror of Opposition spell reverses the effect of a spell, but not the target. So a spell to hurt a person might help them instead. It is a very interesting spell because it relies on so many of the meta-magic layers in Ars Magica, primarily around Muto Vim spells, but there are compounding questions in the details.

Pyrale wrote: Another question regarding spell manipulation : Supposing I see someone starts casting, and I decide to cast a mirror of opposition on his spell. Does my spell have to pierce the caster’s defenses ?

If not, do I have a window of opportunity if the spell has no time of travel, or can I only cast it on projectiles ?

My 2c which might be dodgy… I think you can cast it on anything, and the SG gets to decide what it does.

  • First you need to use the rules for identifying what Form the spell is, because Mirror of Opposition is different for each Form, but I guess you might know if the caster had previously been shooting away with missile spells and just assume you’re correct if your perception Check failed. The Perception check isn’t going to slow down the rest.
    … Perception + Awareness + roll vs. 15 – (effect mag). If the opposing caster has silent/subtle magic/deft magic it gets a lot harder.
  • Then if you are not cooperating with the other caster (fair assumption) you need to fast-cast the MoO:(form), as per p.159 of Ars about not being able to intercept the spell quickly enough. Its basically a -10 to casting roll with 2x extra botch dice, and you need the fast-cast Mastery option for the MoO spell.
  • Then your Penetration total for your casting roll (which includes that -10 mod) must beat the other caster’s Penetration total
    (i.e. spell CT + roll – Spell level + Pen ability vs same from the other guy).
  • The rules imply that you don’t need to penetrate the caster’s parma which is great, although if they were casting a spell with Range: Personal upon themselves I’d argue that you’d also need to penetrate their Parma for it to work too (?).
  • The caster must be in range of your MoO spell too (voice), unless you’ve got a funky version or using an Intangible Tunnel and an AC.
  • I don’t know what happens if they are fast-casting a mastered spell, but I think you still could fast cast to intercept and alter it (?).
  • You can’t alter Spont spells with MuVi which is a bugger but it makes sense why.

Easy! However…

  • If the first spell was fast-cast then the second magus can fast-cast one to defend/intercept, but it should come back to speed (point made here). Essentially the magic system seeks to avoid situations where magi just fast-cast-BLAST their way through all encounters.
  • As MoO and many other Muto Vim spells do not work against Spont magic, and also typically must penetrate against the target spell, and also usually only affect half their level, not many wizards are able to Spont cast Muto Vim spells in defence. It is possible, but very unlikely.



A spell for Interrogating Ghosts

Ghosts are tricky and maddening, especially those who insist on not being helpful no matter how close or far they are from the afterlife. In a recent rpg session the characters where trying to commune with a ghost who proved to be rather uncooperative.

The players used “Whispers Through The Black Gate”, an iconic spell in Ars Magica used for talking to ghosts. The spell is powerful but relies on the skill of the questioner, and wizards are typically poor orators and not overly sensitive to the needs of the dead.

Instead of whispers, the magi could have used force – mentally reading the ghost’s remaining mind, or even forcing it to answer using spells designed to strip truth from the unliving.

Here is a rough outline of how that spell would be presented in Ars Magica Continue reading

Ars Magica Perspective on 20 Quick Questions

Jeff’s Game Blog has a great post of 20 quick questions for your campaign setting. I’m spinning up an Ars Magica game at the moment, and the answers demonstrate just how different it can be to a typical hack and slash setting.

  1. What is the deal with my cleric’s religion? If he is truly a believer then you might be somewhat a bad ass priest. Otherwise is probable your faith is more like a profession, than a calling. Either way the robes are usually comfortable, and the cannon law is very forgiving.
  2. Where can we go to buy standard equipment? If you mean food and clothes, the nearest moderate sized village is 14 miles east. If you mean weapons, then you’ll need a darn good reason to carry them or the local lord might get nasty. Maybe just anger the Lord and take them from him somewhat damaged?
  3. Where can we go to get platemail custom fitted for this monster I just befriended? Talk to a Verditius magus, or make a deal with the covenant smith involving a lot of alcohol and silver. No city armorer will take you seriously.
  4. Who is the mightiest wizard in the land? Probably one of the House Primi, although amongst the upper scale of Magi it is really hard to tell. I heard of a lich living in northern Scotland who is pretty old, but he is also known to be overly nasty too.
  5. Who is the greatest warrior in the land? I’d say that would be a Magus too. A sword, lance, or heavy horse is not much of a match for a well placed Incantation of Lightning. Or perhaps a Bjornaer with a Lion heartshape.
  6. Who is the richest person in the land? Probably the King, although one of the bishops might give him a challenge when it comes to lifestyle.
  7. Where can we go to get some magical healing? Again, go to the Magi in the covenant – and hope you can either blackmail them, or they owe you a big favor. Wasting Vis on healing is almost crazy.
  8. Where can we go to get cures for the following conditions: poison, disease, curse, level drain, lycanthropy, polymorph, alignment change, death, undeath? A good (as in pious) priest, or a Magus. YMMV, as explaining undeath to a village priest will be odd. Entertaining for sure, but also odd.
  9. Is there a magic guild my MU belongs to or that I can join in order to get more spells? Or to ask another question: You mean you want to leave the Order of Hermes? Close your eyes and step toward the Flambeau Magus please.
  10. Where can I find an alchemist, sage or other expert NPC? A city, burning at the stake, or in a covenant. Good people are hard to find.
  11. Where can I hire mercenaries? A moderate size town might avail a few bodyguards, otherwise a large town or city will be needed. Perhaps try chatting to your local lord about setting up a special deal, in exchange for some favour.
  12. Is there any place on the map where swords are illegal, magic is outlawed or any other notable hassles from Johnny Law? In the wilderness nobody can hear you scream. In the cities, the laws tend to be enforced with a straight hand, although to be honest that depends who you know too. Do you have the social contacts virtue?
  13. Which way to the nearest tavern? The covenant has a main hall, will that do? And to find wenches, see same.
  14. What monsters are terrorizing the countryside sufficiently that if I kill them I will become famous? Vikings, ghouls, storm mages, ghosts, ancient intelligent weapons, other Magi; and so on will all grant a good name and some fame for you. They also might kill, rape, pillage, possess, or burn you; which is far less worthy of a story. I’ll be in the main hall drinking with the wenches than you very much.
  15. Are there any wars brewing I could go fight? In Medieval Europe? Probably one per 2 year period either starting or ending. Did you hear the sermon on how great the crusade is? I hear they all get free absolution, which is normally so darn expensive.
  16. How about gladiatorial arenas complete with hard-won glory and fabulous cash prizes? Generally speaking killing for sport is left to the nobility. Jousting is a great way to kill without consequences.
  17. Are there any secret societies with sinister agendas I could join and/or fight? Yes. Plenty. More than you could ever know.
  18. What is there to eat around here? Fish, sheep, goats, and plenty of mead and ale. The monsters of the area feed on peasants, but now and then they get a Companion and Magus too. Yummy.
  19. Any legendary lost treasures I could be looking for? Yes, fingers of the Christ come in singles or boxes of ten. How many can I put you down for?
  20. Where is the nearest dragon or other monster with Type H treasure? The Pyrenees are known for a large drake, about the size of a small mountain – will that do? Else the Leviathan is probably somewhere off the coast of Italy.

Happy gaming.