“Can my Mage character cast effects cooperatively with another character?” is an extremely common question, and one that’s not always easy to answer. The book isn’t very helpful, declaring cryptically:

an Etherite in a shamanic rite will probably do more harm than good. That said, mages from distinct yet allied groups – differing Traditions or Technocratic Conventions – can certainly collaborate
if they approach one another’s practices with respect and attention.

We have opted to provide some guidelines for how to determine whether it’s possible, although they are necessarily incomplete and imperfect. You may wish to review the “Acting in Concert” rules in the M20 Core Rulebook, pp.542-543, before continuing; please also be aware of the Mage House Rules (specifically those that pertain to ritual magic and to extended and permanent effects).

In order for a Mage character to work as a “Collaborator”, the following must be the case. Note that every character collaborating on an effect must meet these requirements for every other character, not merely the one leading the ritual. It’s very hard to get large groups working together on the same effect; that’s on purpose.

Compatible Effect

The desired effect must be something permissible under both characters’ Focus. No matter how close their approaches to magick may be otherwise, if one is trying to do something that is simply impossible under the terms of the other’s worldview, it’s just not going to happen.

Compatible Paradigm

The characters’ Paradigms must be compatible. They need not be identical, but they must be able to interoperate. What does “compatible” mean, exactly? Well, two Paradigms that share an element (e.g., both have “All the World’s a Stage”) are presumptively compatible. Paradigms that contradict each other (e.g., “It’s All Good – Have Faith!” and “One-Way Trip to Oblivion”) generally cannot work together. If two Paradigms have both a shared and a contradictory element, each player should determine which of the two is more central to them; unless the contradictory element is central for both, they can probably figure out a way to work together. In general, mystic Paradigms for Traditions magi are presumed compatible with those of other mystics, and technomantic Paradigms are presumed compatible with other technomancers.

Common Practice

All collaborating magi should have at least one Practice in common, and one or more such Practices must be used to create the effect. Some Practices may have broader compatibility than a one-for-one — “Cybernetics” and “Hypertech” might be able to collaborate if the effect is appropriate, as might “Faith” and “God-Bonding.” Unless there is a pretty airtight justification, however, don’t assume this is possible.

Mutually Agreeable Location

Combined casting generally requires the site of the work to be no worse than neutral to everyone involved. If it’s being done in someone’s Sanctum, for instance, that Sanctum must find all the participants’ Foci acceptable, and therefore the stricter rules for Sanctum use apply.

A Casting All Can Participate In

Every character who is serving as a collaborator must be able to participate meaningfully in the casting process. It can’t be one person doing all the work while the others stand around and watch — everyone must take an active part in the process. If the way the effect is being cast allows only a particular number of people to be meaningfully involved, that’s the limit on the number of magi who can usefully collaborate. Others can still be present to provide moral support, but they will not provide a game-mechanic bonus.

Collaborating Without Collaborating

If you and your best friend don’t have any common Practices, but still want to work together, there are ways to do so. The above applies only to the “Acting In Concert” rules, which aren’t the only way to collaborate! If your Etherite wants to help their Dreamspeaker friend with a spirit summoning, there are many ways to do so — they could create wards around the summoning area in case the spirit gets loose; they could provide the summoner with technomantic assistance to ensure they’re awake and alert when the grueling ritual is completed; and so on. Mage characters have many tools available to them, and can almost always find a way to attack a problem from a different direction in order to make it easier.

Learning From Other Magi

You don’t need to meet the standards for Acting in Concert in order to learn from another Mage, although it will certainly make things easier. Even if your Foci are completely incompatible, you can still gain some insight by observing the results of what they do through the lens of your own worldview. Granted, you’ll pretty much have to ignore everything they say about how they do it, and work backward to your own first principles in order to figure out how to do the same thing (if your Paradigm even permits it). But that can still be an important part of the learning process, even if it’s not nearly as quick and easy as it would be for characters with more closely-related Focus elements.