House Rule for Casting Forcelessly

In Ars Magica Casting a spell forcelessly is a deliberate act by the caster to inhibit their own spell power/spell strength so that they do not risk unintentionally cast a spell on another Magus. I’m not sure what a useful real life comparison might be – however it seems like the wizard is seeking to use enough of their knowledge and power to successfully cast the spell, but absolutely no more. Seems not without some risk.

Is that like quickly physically lifting an object up off the floor only one handspan? Or filling a bottle to the brim but not letting another drop spill? Do it fast but don’t go over.

Sounds like something which should require a basic Finesse check to do properly. Even rated as an easy task (say target value 3+) introduces the potential for mistakes and risk.

(As a counter – Ars Magica is a roll heavy game so perhaps KISS applies)

Perhaps if the Finesse check fails, the Casting Total is calculated normally minus the caster’s Penetration score. Sure, the magus didn’t mean to use a little extra force, but magic is fickle and sometimes hard to control.

On a botch (and this is a skill check and not a magical botch) perhaps the spell is cast as normal including the caster’s penetration skill. Whoops eh?

Images copyright Blizzard Entertainment – WoW BfA (which is what I’m doing to stay sane when I have some spare time and need to explore. Happy killing folks)


Reduced Might Stripping, a House Rule for Ars Magica supernatural opponents


A great house rule to limit the impact of might stripping spell effects on supernatural creatures in Ars Magica – Multiple applications of Perdo Vim do not stack, specifically for reducing a creatures Might or affecting an Arcane Connection. Once damaged only a more powerful spell will inflict more damage. Makes the famailiars tougher too.

Found via a discord group I’ve been chatting to. Clever idea!

An Avalanche spell from Disney’s Mulan

Another snow based new spell for Ars Magica, for a snow, ice and winter magus which is now languishing in a pbp game which never took off.


Creo Aquam 30, R: Sight, D: Diameter, T: Individual

A massive drift of snow is created a spot designated by the caster, as a circular pile roughly 500 feet wide and 200 feet at it’s highest.

(Base 3 to create snow, +3 Sight, +1 Diameter, +3 Size)

Adminitedly it is a spell with very limited usage, inspired from the avalanche scene in Disney’s Mulan (my kids are big fans).

This spell is part of the free new spells compendium for Ars Magica.

Mulan avalanche image - Copyright Disney

A tricky MR question for ArM

I saw a tricky Magic Resistance question for ArM today, and I find it a frustrating demonstration of the MR rules, and a potentially exploitable rule.

RacconMask wrote – How does this react with Target:Part? If I take (for example) a javelin or spear, and cast a Target: part spell to control the butt of the spear’s haft to attack flawlessly with Rego… does that get magic resistance when the un-controlled tip stabs in? Thinking here of an ‘invisible swordsman’ ReFo spell that only controls the hilt of a weapon.

Grumble. It is a great idea as it demonstrates again how MR in ArM can be complicated. Truthfully it is no different from enchancing a soldier with a spell to increase their toughness, and insisting that they use normal weapons. Which is to say the players at the table need to understand a simple rule – When a rule is exploitable it can be used by everyone, and the GM has far more resources. Do you really want your enemies to react in the same way?

As long as the exploit is applies consistently and it feels congruent in the story, let the players exploit. Then hit them with it.

This is the same for Parma Magica burning spells. They look great on paper, and are exceptionally dangerous, but they also will likley impact the players far more once the NPCs adapt.

Changing Wolves to Rabbits, or Lions to Lambs

Previously wrote a transformation spell called “Transformation of the Vicious Beast to the Floundering Fish” to make a beast into a fish, as an attack to quickly kill a beast or allow it to swim, and I was thinking of casting against normal animals and moderately powerful magical beasts. However one of my Magi in a play-by-post game is fighting a magical beast and doesn’t want to outright kill it. Here is an alterative which is designed to be lower level, and also shorter duration – more as an intimidation tool.

Transformation of the Vicious Beast to the Humble Hare

Muto Animal 20, R: Touch, D: Diameter, T: Individual

The targeted animal up to size +3 is turned into a rabbit. A rabbit pelt may be held by the target and dropped to end the spell prematurely.

(Base 5, +1 Touch, +1 Diameter, +1 additional size in target)

This spell is part of the free new spells compendium for Ars Magica.

Stacking Intangible Tunnels variants


A great idea came out of the Ars Forums recently for meta-magic spell stacking using variations of Opening the Intangible Tunnel (Ars Magica, MuVi, p). The idea is to first establish a connection using a lower level version, which has flexibility (like using R: sight), and then cast another which is optimised at a higher level with restricted range: Touch.

It’s a neat trick, and well within the rules.

Milestone 700+ New spells for Ars Magica

The blog has 701 spells in total now – and that is about as many as I intended in ever drafting, so anymore will be far more staggered apart as time permits. Hope they are useful in your games.