can many magi cooperate to open the arts?

[Christian_Andersen (Christian Rosenkjaer Andersen)]

@Tellus

@callen

According to ArM5, if it uses a Lab Total, it is a laboratory activity. That is stated explicitly. Opening the Arts for someone who has Supernatural Abilities uses a Lab Total, so it is a laboratory activity. Suitable helpers may assist in any activity using Magic Theory, which is part of the Lab Total. So according to ArM5 you can have assistants help you Open someone's Arts.

This is my position as well.
I would further add that if this is not the case, we're not going to see a lot of magi with major supernatural virtues who do not also have Strong Parens.

Well, apprentices with major supernatural virtues could have had their Arts opened by a magus from the Line of Pralix. The Parens need to open the arts of his apprentice personally.
However with the use of a lab and all relevant rules for this the magus opening the arts of an apprentice with previous mystical knowledge has a cart load of ways to boost his lab total. Even though Covenants does not list 'opening the arts ' as a lab activity for specialization you still get Aura and Gen Quality added, plus Familiars, plus any In and Vi specializations.

[Christian_Andersen (Christian Rosenkjaer Andersen)]

Also consider, that there are several activities that require a lab without needing a lab total generated: Fixing ACs was mentioned earlier, but also a Vis Transfer (ArM5 page 95), and last but not least Preparing for Enchantment - this last one does not need any specific lab total to do, only the requires Magic Theory score to use the relevant amount of vis. Oh, and also Items of Quality from Verditius Mysteries.

But I can't remember a single thing that uses a Lab Total but explicitly does not require a lab. Which is why Opening the Arts does indeed sound like a Lab Activity. Even though an apprentice without supernatural knowledge doesn't require even a lab total of 0 and therefore by leap of logic no lab.