I only stated that it was possible, not that it was probable.
I did not find the actual simulations. I am most interested in all the assumptions ... how much stress die magic do the magi use, especially late in life? what health bonuses do they have? what longevity ritual? Etc.
A magus can, quite easily, avoid twilight by only using non-experimental lab activities, mastered spells, and non-fatiguing spontaneous magic. Some magi, surely, will grow so cautious that twilight is not a risk, while others are so deep-heartedly proud and reckless that they are bound to end up in twilight.
To answer the original question, I would leaf through some tribunal supplements and look at what they describe as mature and ancient magi, and work off that. Player magi can easily be munchkinised to outlive the most ancient ones by decades.
I agree with loke that a careful magus could, plausibly, avoid Twilight rolls. I also find it highly likely that extremely-high lab-total longevity rituals can be procured (easily 200). In principle a magus could live for centuries by the rules, in such a manner.
I personally find long-lived magi a hindrance to the setting. I prefer to think that at around Warping 7 (105 years post-gauntet; at the ripe age of 130) some disaster or another will find you, if one didn't find you earlier, so that forms the top typical lifespan. With longer-lived magi generally privy to Mysteries involving immortality of one form or another.
Does it matter whether the all the centennial magi are thrown into final twilight or lock themselves into their sanctums to avoid it? They are out of the story for all practical purposes in either case.
An elderly magi doesn't need to be cloistered away. They just need not to cast risky spells. They could still wield incredible political influence. They can use significant powerful magi items, and just cast spells they've mastered to still look the part of a magi.
To me the keyword is plausibly. Yes some magi could find longevity rituals with a lab total of 200. Some of those magi could also manage to avoid final twilight and not have some unlucky "critical hits" on their aging rolls that pushes them to decrepitude 5. But I doubt that more than a few magi could pull off this stunt. As a result it would happen a few times in the history of the order and those magi who do pull off this feat of longevity and activity become legendary for the influence they can accumulate and for their apparent immortality.
Absolutely. And for this reason I prefer to use the canon magi from the tribunal books to indicate typical ages. Cantarus at Qui Sonant Pro Quieto in Hibernia is 130 and thinks himself close to death. The oldest Hibernian magus is 172 and retired.
We can easily rig the assumptions to make a simulation confirm the canon demographics.
Yes, a 200 LR is possible, but not «easily». You need to pile up every relevant specialisation, with a magical focus and a tuned lab. A magus who starts life with a focus and the determination to do it, will do it, but it will take a century. That's unlikely to be more than one magus in a generation, and then the question is, will he make longevity rituals for the other centennials? Or does he prefer to spend the time on himself. The rituals he make will be so ridiculously expensive that if he is in it for the vis, there is not much point in selling more than one or two per decade, so it is not going to support a large number of centennial magi.
You should also not exaggerate the will to live. Have you read Heinlein's account of Lazarus Long? It does make a lot of sense that many centennials cease to fight to survive.
Or just plain quality of life. Even if you have a great longevity ritual running, once you hit Decrepitude 4 you can't do anything stressful without Crisis rolls, and Crisis rolls are really, really bad when you're old as dirt, and longevity rituals burn out to resolve Crises. So one single stressful event leads to a lost season and the need to renew your LR. Pretty bad, and probably the main reason magi retire.
This is one reason I really, really like the Unaging virtue, which lets you ignore most of the effects of aging and you're not crippled at Decrepitude 4.
On the topic of aging if one is willing to delve into the rules for breakthroughs there are some potential modifications here.
- Integrating the Mercurian ritual that removes Decrepitude. This can be seen in Mythic Locations.
- The various integrations that allow one to add Corupus as a modifier to Longevity Rituals.
On a related note of aging I honestly like the idea that the Gift of Hermetic Magic leads to magi who remain viable in body and mind up until they basically die. (Like how Dumbledore is a few centuries old and still completely functional up until the curse.) In Ars terms this is probably something like the Unaging virtue or modifying how longevity rituals work - maybe taking it out of ritual and making it a fact of magic, but that is a whole nother discussion.
Buut this does lead me to deciding I'm going to think of a way for my character in the saga I am writing would gain the Unaging virtue. I obviously want it to be a quest slash adventure though I don't know the details, obviously, yet.
I always found it odd that the Corpus bonus didn't factor in, but that probably would have been too much, as a LR specialist will have a mighty Corpus art to begin with. Not having it affect aging actually frees magi to NOT study Corpus extensively (probably a good thing).
One thing to not ignore is the familiar's Bronze Cord score. As good as the Gold Cord is, getting a 3-5 point adjustment to aging is adding a lot of years to a magus.