This was an idea I had. The cost of maintaining a big network of ley lines can quickly get steep (as it should be), but the drain is on regency points... which are needed for spells. Since the Alchemy spell offers us a way to turn regency into gold, I think there is room for a way to change the regency cost of a ley line network into a gold cost.
Alchemy allows a mage to turn Regency Points into Gold Bars at an exchange rate of 4 to 1. This goes the other way, but at a 2 to 1 rate... so 100% poorer conversion rate. I do not think this will be game breaking, it will allow mages with a steady income to maintain a larger ley line network without reducing the RP they have available for spells. Only those with a income base will want this building, so it is not for every mage (that way we won't have to wonder why everyone hasn't build one of these things).
The last part about mixing maintenance and start-up cost might be too much of hassle. The simple solution is to have it be all or nothing - either it has to support the entire ley line, or it has to be turned of.
Ley Line NexusDescription:
The Ley Line Nexus maintains the Mage's ley line network for him. It become slightly more stable and difficult to disrupt, but the advantage is mostly that the Mage can support the network with magical components instead of his own power.
The Nexus can take many shapes, but some kind of conversion device is needed - this usually takes the form of a forge into which magical components from across the land are thrown. They are burned in the magical fire and thus sustains the Ley Lines.
DDC 12
Build Cost 10
Upkeep 0.25 GB + 0.25 GB per 1 RP cost of the Ley Line.
Benefits
The Nexus must be built in a province in which the Ley Line to be affected originates, terminates or has a hook-up there. The Nexus allows the Mage to turn the Maintenance cost of the Ley Line, including all extensions and hook-ups, into gold bars instead. For each 4 RP that would be needed to maintan the line, 1 GB is used up.
This gold represents magical materials gathered and bought throughout the land. Plants gathered at sources, magical charms, spell components, etc, are gathered and sacrificed at the nexus.
This also makes the Ley Line the nexus maintains slightly more stable, granting it a +2 modifier to it's SR versus attempts to tamper with it.
The downside of the Nexus is that it tampers with the flow of Mebhaighl in the province. This can weaken the barrier between the worlds, making shadow world incursions more likely or make it easier for magical beings to gain entrance. What this means exactly is up to the GM, but there should be a 10% increased risk of magical events in the province.
The Nexus must either be turned completely off or on, there is no halfway. Either it supports the entire ley line, or it does nothing - in which case the +2 bonus to SR disappears.
Inspired by: Alchemy spell
EDIT: Boosted the conversion rate, made it more expensive and made it all or nothing. I like this version... Perhaps time to ask the dms if I can actually build this thing, once I get the cash
Conversion rate might still need to be 1-3 instead of 1-4 though...
Hope this is not considered thread-jacking... if so I apologize.
Not a lot of comments on the other buildings suggested, they look good to me, though the academy description needs to be clearer. I have trouble understanding exactly how it works.
Also, note that the Mebhaighl nexus grants the equivalent effect of a 6th level spell - enhance source. 25 GB is a lot though, seems fair.
Perhaps it would be an idea to require Research action in order to build structures that are magical in nature? Perhaps including religious buildings (finding the right prayers, consecrations, and such).
