Sir Tiamat, by realms you mean domains? Because it is possible to be in charge of a realm but have no holdings by purely being a provincial regent. The holdings within the realm may be vassals or independent from the provincial regent.
The word “domain” has been used by us mainly to imply that a domain regent has at least one holding of some sort under their control. Strictly speaking, a realm is a subset of domains.
Sorontar
You are correct, I incorrectly referred to domains as realms. I just reread the BRCS and a realm is a domain with at least one province: indeed a subset of domains. It seems that I needlessly complicated things by wrongly referring to realm where I meant domain… 
Ps Thank you for pointing my mistake out to me, I have now clarified my earlier posts. 
Crystal clear now, then forget what I said
Something to also consider is how these scores reflect the physical aspects of the province (which is one of the reasons why I think you need to seriously look at individual provinces and not just the domain itself).
The more people (actually better described as the more economic development) in a province the less “nature” there is - that is the physical landscape is modified to make room for the people - trees are cut down and farms are developed, etc. Elven lands are the exception of course.
The changes in the physical landscape reflect how the land’s current potential for defending against/attacking via magic.
These are the things I have been trying to make a connection with the domain ability scores.
I am not sure what you mean with “potential”. A province with a higher source level, could support more source holdings and would therefore have more magic potential?
I do not see how the physical landscape should reflect the magical attack capabilities of a domain perse. Granted, a more developed province could not support the same source holding level and the source holding level would affect the magical attack capabilities. However, a domain consisting of a single level 1 source holding should have the same magical attack capabilities irrespective of the development of the province.
I want to keep the domain scores seperate from province development, because although province development caps the holding potential of a domain it does not directly affect the attributes of a domain. A domain consisting of a level two guild holding in a developed area, should not be required to be different from in scores from a similar level two guild domain in an undeveloped area. Surely there are to be likely differences between the domains, but these should mostly cosmetic. Incorperating cosmetical differences between two similar domains in the mechanics would in my view become needlesly complex.
Further note that in the current proposal there is no such thing as a magic defence. As per fourth edition, all attacks, including magic attacks target one out of four defences - i.e. fortification, resilience, security, or loyalty - depending on the attack power. These defences are based on the characteristics of the domain and the targetted holding.
These are precisely the things that are a deviation from core BR setting principles - that is what I have been trying to call your attention to.
As a core BR setting principle [FONT=Verdana]mebhaighl is the arcane magic power of the world and it is directly tied to the development of the land (inversely). That is forests and mountains contain more [FONT=Times New Roman][FONT=Verdana][COLOR=white]mebhaighl that can be tapped than do cities and farm lands.[/FONT][/COLOR][/FONT][/FONT]
I do not understand why.
As a core BR setting principle [FONT=Verdana]mebhaighl is the arcane magic power of the world and it is directly tied to the development of the land (inversely). That is forests and mountains contain more [FONT=Times New Roman][FONT=Verdana][COLOR=white]mebhaighl that can be tapped than do cities and farm lands.[/FONT][/COLOR][/FONT][/FONT]
True, and I have no desire to change that.
Domain ability scores are not intended to refer to the nature of the lands. They refer to the human - or others races’ - creations. The ability scores are designed to represent the collective abilities of the regent and its followers.
The nature of the land/province, will continue to exist of a province level and a source level irrespective of domain ability scores.
Forests and mountains will continue to provide high levels of mebhail. However these high levels of mebhail are not part of the domain until they are harnassed in source holdings.
I disagree with this one totally.
A Source (1) versus a Source (10) is a vast difference in magical power. The higher source level allows access to higher level realm spells, which in a logical power progressive system (like 4th ed) translates into more powerful spells.
So a higher source level should have a higher magical attack potential (or rating).
A similar perspective exists for developed province. The higher the development the better and more troops the province can support.
Look at the Imperial city. Basically a 10/0 province. Tremendous troop capacity but no magic potential. This excluded the use of things like ley lines – but those are things that tie difference provinces together.
But sources and all other types of holdings are mutually exclusive of each other by definition, except for elven lands.
Sources do not have a “follower” relationship unlike the other types of holdings. It is instead a bonding of the wizard and the land itself (unspoiled and uncultivated).
The nature of the land/province, will continue to exist of a province level and a source level irrespective of domain ability scores.
Forests and mountains will continue to provide high levels of mebhail. However these high levels of mebhail are not part of the domain until they are harnassed in source holdings.
Logic (and the setting itself) dictates that this can’t be - it is impossible for a province, again esxcept for elven lands, to support a high level of development and and a high level of source potential at the same time.
At least in part game balance - currently you either have high wealth/industry or high magic, or a trade off between the two. If there is no trade off then the stronger economic realms have no compensating factor to help the economically inferior realms survive - and there is no reason for a ruler not to max out all areas of power.
I think that your system has a similar effect at one remove - a mountain will have low possible domain score and high mebhaighl potential, a plains the converse.
The direct link between increasing domain power reducing source potential is being lost which reduces conflict (the source holder will not oppose any increase) and makes economically realms more powerful (since no source potential is lost) making it less likely that less populous realms could survive. That moves you away from typical BR issues of the forest realm resisting the plains realm by use of more powerful magic to outweigh the plains realm’s economic power.
I will now post a short comment and expand at a later time (when it is not so late) 
As I see it, we are dealing with a misunderstanding. It seems that I am currently failing to make clear what I mean.
I totally agree with you points: development hampers source potential and in the proposed system I intend to keep it that way.
The proposed system does not deal with source potential and development, it leaves it intact as per the AD&D rules. Apart from province levels and source levels, I attach ability scores to each domain. Agian these scores are intended to represent the domain, I do not wish to change rthe province and source levels. Province and source levels will continue to work as before, however domains -the total number of holdings under a single regent - would receive a score in six abilities.
It is quite frustrating that either I am not able to understand your points, or I am not able to clearly communicate my design… 
The point is that we do not see any way to make the connection between high source potential and a specific ability score or one that makes there be a trade off between the source ability score and the economic ability score.
It appears it is all DM fiat and everything is considered when you do it, we just don’t see the transparency.
I believe that I am sort of understanding both sides here so I will try to summarise.
Irdeggman has been pointing out:
[ul]
[li]Each province has a maximum number of possible non-source holdings defined by its province level
[/li][li]Each province has a maximum number of possible source holdings defined by its source potential level.
[/li][li]Mebhaighl is everywhere but there is more of it available when a province has been less developed.
[/li][li]Provinces with high levels are more likely to be more developed than provinces with lower levels.
[/li][li]As province level increases, the source potential level decreases.
[/li][li]The terrain limits how much the province level can increase to.
[/li][/ul]
At this point I will point out that just because the province level is high, does not mean that it actually has any non-source holdings. Likewise, the source potential level is the “potential” source holdings, so there may not actually be any (and often aren’t).
What Sir Tiamat has said is:
[ul]
[li]A source holding (level 1) is the same strength regardless of what province it is in.
[/li][li]So source holding (1) in a province of source potential (4) is equal in magical strength to a source holding (1) in a province with source potential (1).
[/li][li]For neither of those source holdings does their magical strength get affected immediately by the province levels, ie. what level of development/population etc may be in the province.
[/li][/ul]
The problem is deciding what to do if a magical attack occurs against a province (not a holding). Sir Tiamat is saying that under 4ed the rules would deal with the effect of the magic not the fact that it is magical. Therefore, any provincial defenses would not be combating magic, they would be resisting what the magic does to them. Therefore, it is irrelevant what a province’s source potential level is and whether there are actually any source holdings in the province. They are not what is combating the magic.
Irdeggman countered by saying that in BR it is the land’s magic that would be combatting any magical attack. The more mebh. in the province, the better the defence. The more mebh in the province, the higher the source potential level. The higher the source potential level, the lower the province level (let’s forget about elves for a moment). A province’s magical defenses don’t require actual source holdings.
I hope I haven’t misrepresented anyone’s comments here. I also hope I haven’t confused things even further.
Sorontar.
Pretty close Sorontar.
I just think that somehow there should be an interlock that says the total ability scores associated with development and with sources should be tied together so that there is some sort of trade off between the two.
Or better the scores for development and sources should be tied to the province itself. What I mean is that is should be impossible to have a high source score in a province 10/0 (barring things like ley lines that is).
Oh and I agree with Sir Tiamat that a source (1) is the same regardless of where it is located. But I never saw a tie between the holding levels and the ability scores either (it was not transparent in the posts). I might not have been clear on this one in my posts.
Thank you for your intervention. 
I am grateful for your input
You pointed out that you see no tie between holding levels and ability scores. That is correct; currently there is no specific relation between holding levels and the ability scores. There should be, but this link is not yet developed.
I do have some general principles how I would like to tie holding levels to ability scores:
[ul]
[li]Larger domains, - i.e. domains comprising of a greater number of holding levels - should have higher scores than smaller domains.
[/li][li]Different holding types would contribute to different abilities.
[/li][li]The total number of holding levels rather than the holding levels per province would contribute to the ability score.
[/li][/ul]
The ability scores should represent the collective characteristics of your entire domain: the multitude of talents, resources and abilities of the regent and all of his/her followers. As such, they are not tied to development or to magic. The proposed mechanic is not designed to represent specific holdings or provinces, nor is it designed to deal with the level of province development or the level of mebhail within provinces. In the proposed system provinces would simply retain their development and mebhail score.
The main problem of the system I propose is how to create a believable and yet simple to use these aggregate domain ability scores to take actions at the province level. I think this can be done but again I have not worked it all out just yet.
You are welcome. Like I said originally I think this concept has promise.
You pointed out that you see no tie between holding levels and ability scores. That is correct; currently there is no specific relation between holding levels and the ability scores. There should be, but this link is not yet developed.
I do have some general principles how I would like to tie holding levels to ability scores:
[ul]
[li]Larger domains, - i.e. domains comprising of a greater number of holding levels - should have higher scores than smaller domains.[/li]> [li]Different holding types would contribute to different abilities.[/li]> [li]The total number of holding levels rather than the holding levels per province would contribute to the ability score.[/li]> [/ul]
This is starting to make more sense to me. Although I think that the total number times the level of the holdings in question is a more realistic method.
5 level 1 holdings are not worth more than a single level 5 holding. Much more can be done with a single level 5 holding than can be done with 5 level 1 ones. The size of the holding determines the level of realm spell that can be cast and the type and number of troops that can be mustered, as well as the economic generation of the holding.
The ability scores should represent the collective characteristics of your entire domain: the multitude of talents, resources and abilities of the regent and all of his/her followers. As such, they are not tied to development or to magic. The proposed mechanic is not designed to represent specific holdings or provinces, nor is it designed to deal with the level of province development or the level of mebhail within provinces. In the proposed system provinces would simply retain their development and mebhail score.
The main problem of the system I propose is how to create a believable and yet simple to use these aggregate domain ability scores to take actions at the province level. I think this can be done but again I have not worked it all out just yet.
I think that the “difficulty” here is that you are pushing for a domain level score and then trying to use that for domain level actions.
While nice for “color”, in practice I don’t think this will prove very useful.
Most actions are not performed at the domain level but rather at the province or specific holding level.
While keeping scores at the province level exponentially increases the difficulty (e.g., booking) of your system it is actually essential to game play.
For instance what is the true contribution the loyalty, mobilization and size of a law holding 3 provinces away has when one is defending an attack a law holding in a different location?
I think if you focus on individual provinces first, then a system to roll them up to represent the domain will be much easier.
BR is by it’s very nature a book keeping nightmare and I don’t really see a way that easily eliminates that aspect fo the game. The best we can hope for is a system that can be arranged to make automatic calculations easier (e.g., something that lends itself to spreadsheets or something similar).
The proposed mechanic is not designed to represent specific holdings or provinces,
So what do you do for the king who has control of one or more provinces and a few law holdings? Do you only use the holdings?
And what about the King who has no holdings but has a vassal/s who is in charge of the law holdings.
Sorontar.
I think what you would do if working from a ‘build up’ basis is total the ‘friendly’ domain holdings in the province and use the sum of the accumulated strengths when determining attack/defense values.
You could make the increase in power non-linear to reflect a L3 holding being better than 3 level 1’s if you wanted to.
Tying in the trade-off, you could have some of the benefits of larger populous holdings have a negative impact on source holdings, rather than all changes being purely additive. That way as people power up their domain they have to trade off. So if someone wants to increase income with a grand highway, series of water wheels, terraces, or whatever else you use to represent increased output, they get an advantage (higher output and stats) at the cost of impairing the magic level. This shifts the trade-off from population to industrialisation but that doesn’t sound too wrong.
As I see it now, one would use a basic score, modified by the total number of holdings (and other modifiers such as domain level). This means that a king with more provinces and fewer holdings will generally have lower ability scores than a king with less provinces and more holdings. The poor “puppet” king with a large number of provinces and few holdings under his rule may have the legitimacy, but not the power sources required for effective rule.
And what about the King who has no holdings but has a vassal/s who is in charge of the law holdings.
Sorontar.
good point.
In my mind there are two ways to resolve vassalage:
[ul]
[li] The vassal has its own score and will (mostly/sometimes) act on behalf of the king.
[/li][li] The holdings of the vassal count towards the score of the king as long as the vassal supports the king.
[/li][/ul]
Currently I think the latter option is best, but I am open to other opinions and suggestions.