As many, many, many have said before. The third edition books could use the update the most. And Heirs of Merlin is in least need of a update, though a new take on it that has a Cad Gadu more in line with the one described in HoH:S could be interesting to see.
Though if Stonehenge was given a 5th edition version, then I hope that it remains compatible with Nigrasaxa and Promises Promises, or that those gets updated version as well in the process to conform with any changes to the Tribunal as a whole. Seeing those two but with ArM5 stats would actually be interesting regardless.
If the devices were designed especially for them, then they won't take any warping. So that part is a non-issue.
I'd guess there would need to be a balance between how much it costs, and how much material is being produced, so even under such a plan, it's not likely gonna be 1 updated Tribunal per month, unless you do it as PDFs, and not printed.
You and your team have probably discussed plenty of ideas for this, but here's my two cents:
Updated Tribunal books
Short compilations of adventure seeds
Magi of the Month - stats for a Magus, a la, Magi of Hermes, with new spells, items, and such.
A Year in... - Looking at a specific year, in a specific Tribunal, and noting some of it's events
Yearly Renewal - Once a year do a product that discusses some possible breakthroughs, or Mysteries, and maybe add more spell Guidelines.
Hedge Tradition - Add a new tradition. This could start with any hedge traditions you feel are missing or not represented in the current rules, from Europe, and then slowly expand outwards. And would be nice to have it also represented as an Ex Miscellanea if it gets integrated.
For me: Ars magica has plenty of breadth but is somewhat more lacking in depth. By which I mean, there are enough hedge traditions, rules for playing craftsmen, nobles, academics, rival magicians, foreign magicians etc. I like all those things, but what I often lack is detailed libraries, covenants, magic items, characters etc. All of them ideally rather vanilla hermetic magi, companions and characters that are not exceptional in any particular way. The community does a great job at filling this hole but more is always better.
Part of it is that there is a pretty hard limit to how much exotic magic can fit within a saga but you can always cram one more "normal" magus or hermetic magic item or mundane village in a saga.
Detailed stories that are close to being an out-of-the-box campaign would be nice too. I like the adventure seeds but they tend to require a lot or work to get rolling.
Some of my favorite material of the entire product line are the chapters XI and XII in GotF detailing ideas for sagas in the rhine tribunal, in particular the curse of the rhine gorge chapter. The pathfinder RPG har had great success publishing adventures like this too (I dont know if it was financially successful, or if it would work for Ars).
Redcap news is a particularly great idea as it is a lot of work to come up with stuff that happens in the order and stuff happening is what makes the setting feel alive. Just normal things magi bickering over stuff and prosecuting each other, vis sources being discovered or lost, magic items rediscovered or lost, probably many more that I cannot think up right now, that brighter minds probably could.
Another thing I would appreciate is a detailed look at different mundane "things" that a covenant might interact with. A detailed piece or series on the functioning of a medieval village, or different types of village with a fictional village as an example. I dont really want stat-blocks so much as a list of persons with personalities, motivations and such. Same could go for monasteries, noble estates, towns, craft-guilds, whatever.
I very much feel the same way. I know that everyone else on the discord seems to be hugely into hedge mages, but I don't see the point of adding yet more of them. The core of the game, to me, are the hermetic mages and the Hermetic magic system. What needs to be fleshed out is the "normal" rather than the outliers.
What I found hard when starting my Rhine Gorge saga was finding pre existing examples of adventures, which is one of the reasons I have posted my own. I like that the book has the chapter on possible sagas and events.
I really liked the Apprentice book, and I think more "short" books would be a good way of bringing an interesting but limited-in-size concept to paper.
Another thing I would pay money to have is a somewhat detailed ruleset made for building magi who are sort of in the early-middle or late beginning of their career.
I am playing with a group of mostly new players, and we have used the character creation rules from the core book and it is a decision that I have regretted more than once. We used the core-book rules because they were easier than making up our own rules or advancing characters.
But the character that we created are often comically incapable of dealing with even trivial problems of magic. I like the rules for new magi, but in my experience they create magi that have a long way to go before they can do the kind of things that i expected them to be able to do.
I imagine a ruleset where there is a simple system that allows a magus to start out with a familiar, talisman, magic items (created by themselves), spells, vis, friends, enemies, etc. but also one that streamlines the allocation of xp. Currently I imagine something similar to the advancement packages from the "Grogs" sourcebook. Because adding age to a magus in the base rules tends to swamp me with lots of xp that I have a hard time figuring out what to do with in order to spend it constructively.
As someone who likes Hedge Wizards enough to have built a saga around featuring them heavily I agree that it's probably not the aspect of the game that needs attention.
Between the canon Ex Misc traditions, HM:RE, Rival Magic, Holy Powers, Infernal Powers, Faerie Magic, and the variants in the tribunal books there are already rules for a huge number of hedge traditions. More importantly, with so many examples it's pretty easy imo to make a tradition yourself if you really want to. Fiddle with one of the existing hedge traditions - add or remove some elements and toss in some appropriate virtues (with initiations) and you can cover pretty much any base.
I've yet to come across an idea for a magical tradition that I haven't been able to boil down the 5e rules for to "Tradition X, plus Y, minus Z". I don't see the value in another book on hedge magic, when there are areas of the game that never got a single book never mind 2+.
Something I would like to see more of are guidelines and examples for how mages need to interact with mundanes (peasants, nobles, church). What kind of demands and concessions are usual in these interactions. And how this varies between different areas of Mythic Europe"
For example: Do covenants typically pay taxes and/or tithes to nobles and/or the church? It is clear from the existing books that some do and some don't - but it is not clear what is typical in each tribunal.
Much of this is largely handwaved away with a "treat it as you want in your Saga", but I would like a more solid baseline to start with - which I can then of course change if I want to.
I could also see some material focused on a changed premise. So image if 'Hermetic Magi cannot serve as Court Wizards" was removed, now some material on using them in such a way would be useful and fun and helpful.
I like new magics, especially ones that Hermetic Magi can use. But I especially like ideas on how to use what already exists in various alternate ways. Even more I really like adventure seeds and potential campaign plot points.
Something that would be really useful would be a combined and clarified spell base guideline. You could give a general range of effects at each base #, then include examples. Include an actual breakdown of things like the Complex modifier. Effects achievable by Requisites (both +0 and +1). Design the whole thing with the feel of a Summa on Magic Theory.
It would massively cut down on some of the flame exchanges that happen on the forum. For me this would be a "Shut up and take my money!" product.
I don't need the whole rules to be rewritten or anything but a single, comprehensive, expanded, dynamic source of spell guidelines would be awesome. That and spell examples and such with said guidelines.
It might be useful for the line to have a "living game" component. Ulisses Spiele has the Aventurian Herald, which is an in-game newspaper. There is a risk of canonization of events detailed in such a publication, but it could also provide really helpful elements to shuffle around in individual sagas for embedding convenants in the greater order not just history.
I'd like to see interesting bits of obscure myth and history that I may not have heard of before, expanded into an encounter, location, or hook for my game. I'm beginning a campaign in the Tribunal of Thebes, and while I'm familiar with the most well-known mythic personages and beasties in Greece, I don't know much about the small local myths, and nothing at all about what is lurking at the edges of the map.
I'm sure that Asia Minor had the full complement of critters, powers, and mystic locations before the Turks came in, but I have no idea how to find out about them. Possibly the oldest site of worship on Earth is there - Göbekli Tepe - and I only heard about it because of the incredibly random YouTube recommendation system. Neighboring Georgia is the home of the Golden Fleece, possibly the home of the first production of wine, and borders the mountains where Prometheus is chained. But Google searches for the region insists on giving me results from Georgia, USA, not matter how I structure the query. (Probably because the country of Georgia pays less for ads than Georgia-based Coca-Cola.) There is a lot of information out there, but getting it isn't easy for a casual researcher.
So I'd like to see unique creatures, locations, and treasures in the various tribunals, with a short write-up about the history and myth and some ideas how to use them in a game.
So something in the vein of Mythic Places, but focused on a specific geographic area? I could get behind that. Especially if you went the Mythic Places route of trying to suggest how the location/creature/item could be moved to other tribunals, to give the book wider appeal.
This might be location based I think, I'm in Europe and have the opposite where I get results about Georgia the country mixed in even if I google "Georgia usa xyz". Maybe try going into incognito mode and changing your region on google search to Georgia itself would make for better search results - setting my region to USA definitely changes my results to have more stuff about the state.
For me Stonehenge definitely deserve a rewrite, not because of Blackthorn but because I think it focuses way too much on history over myth : the supplement describes the mundane life of England over 110 pages and just have 55 pages for elements like politics (including mundane), the Order of Hermes and mythes. I think this folkore from England and Wales (Scottland and Ireland having their own Trubunal) is so rich and intersting it's really a missed opportunity.
I don't think most of us saying Stonehenge needs the least work are saying it does not need a rewrite, since the whole point of putting out a 5th edition version of it would be a rewrite. What we are saying is that it has an extremely solid base from which to add the things found in the other 5th edition Tribunal books too. Because it has so much material that the writers and editor would be able to pick and choose from, rather than having to start from nearly scratch (Rome I'm looking at you here), it would be the easiest.
IMHO, that's exactly why it is the most deserving of an update of all the 4ed books.
Ars Magica is a difficult game to get started with, because of the complexity of the setting. There is a shortage of complete, ready to play, settings and stories. There are many excellent story hooks, but it takes some work to build up the setting to support them. In a sense that makes for a great game, but it also makes it harder to get started.
Now, Stonehenge has the potential to be an excellent tribunal for starters, for several reasons. Firstly, English history is relatively well known outside England, and a large international populations has more history and myth to build on than they would for most other regions. Secondly, centralised rule makes the politics somewhat simpler to understand and work with. Thirdly, the existing supplement is an excellent foundation, with several usable plot hooks, and two free bootstrap stories (albeit 4ed).
Therefore, if you want to attract more players and SG to ArM, I think the best strategy would be to take a great tribunal, like Stonehenge, and make it greater. Taking a poorly designed tribunal, like Iberia, and make it decent will possibly have greater value to experienced players, if that's your priority.
The fact is that when my players went to adventure in England, I went to find interesting sites of folklore and myth in my Pendragon collection, because there wasnât anything for me in the Stonehenge book.