Multiple Casting

Multiple Casting is an ArM5 Spell Mastery Special Ability that lets a magus cast the spell several times at once. This allows the caster to affect multiple targets in a single combat round.

Errata

The wording of the rules (in the first printing) is a little unclear about exactly how many versions of the spell a magus may cast. The following errata errata clarify them a bit:

So if your mastery score is 2 and you have the Multiple Casting special ability, you could cast up to 3 instances of the spell simultaneously: the original plus two additional copies.

When Multiple Casting Can Be Used

In Fifth Edition, a magus can use multiple casting only on formulaic spells that he has mastered, and for which he has chose the "Multiple Casting" spell mastery ability.

Concentration and Multiple Casting

The Concentration Table on 82 of ArM5 has an entry for "Casting Another Spell," which sets a very high Ease Factor. The rules are not explicit about when exactly a magus can cast two spells at once, so it's not clear whether this refers to multiple casting.

The consensus from a discussion on the official forum is that whatever "casting another spell" means, it doesn't refer to multiple casting. The rules for multiple casting don't mention any requirement to make a Concentration roll. Furthermore, the Concentration Ease Factor for "Casting Another Spell" is prohibitively high, so it would render the Multiple Casting spell mastery ability nearly useless in practice if it applied.

References

• Multiple Casting: ArM5, page 87