I am very glad that Frogboy starts considering Sovereign succession.    I am proposing the following, a system involve a lot more fun & involvement from players.  Make the succession be a main part of gameplay (as an pre-game option)

When the Country A sovereign dies, an unique "Ark of the Essence" spawn somewhere in his country.  Only those who appears in Country A's Dynasty chart can 'equip' the Ark, including those are originally from other country.   Otherwise, the Ark cannot be moved.  Those who equipped with the Ark rules the country and gain the ability to use Essence.   The ark can be destroyed by some special magic (that requires 10 turns of casting time); when it is destroyed all cities/land of the country is destroyed, game over for that player.

Before the Ark is found, the player of Country A cannot make use of Essence, cast spells, use diplomacy, research spells/tech etc.  Basically, the player can only recruit or move troops but not much more.  Player A are forced to ask one of the bloodline to find the Ark ASAP.

Prince & princess can be married off to other country & so they are 'relocated' to another countries' Dynasty chart.   Even they are moved to another chart, the original player can still  have huge influence on them, because of an "Affinity" mechanism.  Everyone listed in the Dynasty chart has one "Affinity" value for each players, but its exact value is not displayed.

Assuming I have a high affinity with MY princess married to Country A, I can ask her to do many things inside Country A, by right-clicking her info card in the Dynasty chart.  Some examples:

1. share her line of sight (LOS) to me
2. espionage, sabotage, steal tech, 
3. improve my own popularity/prestige in Country A,
4. spread rumor to damage Sovereign A.
5. steal/smuggle items/troop/$ from Country A to me,
6. have influence in diplomatic treat,
7. Give me complete control of her for certain number of turns,  so I can ask her to do battles etc.
8. Make part of Country A to be my vassal
9. break away from her current Sovereign & come under my control/owernership

Doing any of flavors above consume certain amount of her Affinity points to me.

In most of the game time,  even her Soveriegn (Player) do not know where she is because she does not share her LOS to the Sovereign by default.   Affinity point has to be spent to ask her to share her LOS, or control her for a period of time.    They are 'special' heroes that are minding their own business most of time,  unless Affinity points are spent asking them to do something specific.   They are invisible in the cloth map to all players most of time.   Depending on their instinct occupation, they spend most of their private time governing their own allocated land/city, exploring dungeons, killing roaming monsters to level up, accumulating $, etc, all invisible/uncontrollable to the Sovereign's eyes.   

Even my princess now displayed in Country A's Dynasty chart, I can increase her Affinity value towards me by doing one of the following:

1. gifting $/items/troop
2. sparing her life, when she/her husband/son lost a battle with me.
3. let her son marry one of my bloodline

However, the action of Sovereign A has more ways to affect her Affinity value to him.   For example:

1. give her direct family more $$/land/item etc
2. arranging a prestigious marriage for her/her direct family
3. give her ample opportunity to level up quickly
4. force her to lost battles, by not providing overwhelming force
5. the Sovereign lost lots of war/Prestige/controlled area
6. someone spread rumor against the Sovereign
7. or, someone has murdered her beloved husband/son, etc etc.  

Finally,  if that send-away princess of mine happens to be the first one to equip the "Ark of the Essence" and she has high affinity with me,  I can ask her  to surrender the Country A to me, because I have accumulated enough Affinity points to spend.   I can pay lots of affinity points to directly control her, give her free troops etc, during the search for the lost Ark.   Player A can compete with me on who get the final control of her, by spending Affinity points or performing other actions.

If the princess is not the first one to equip it, I can help her.  Killing the current Ark bearer so she can equip it instead. A bloodline assasinating the Sov is possible, although difficult to execute as lots of affinity point is required.   However, if devs want 'Personality' can be introduced to all bloodlines, so the increase/decrease of Affinity point is different for different person.   Some of them wants to kill the Soveriegn without any other players' meddling.  

I don't think the "un-PC" nature of a male-driven succession will hurt the game.  Medieval: Total War allowed you to get a +1 Dread attribute by putting fathers/brothers on top of princess units, for goodness' sake.  Medieval II got rid of that, but still had princesses as diplomats on a timer: get 'em married off for the diplomatic benefit, or see them retire to a nunnery.

Climber's idea is interesting, even if a bit flawed - nothing a polish can't fix.

Why is it good?

• First and foremost, it provides an event after the death of the monarch. The nation could have one more chance to redeem itself by finding the rightful successor for the throne;
• Second, it is not a bland event, but an extremely dynamic one. Every other nation could take part in this treasure hunt and hell yes, I can imagine the enemy's agents leaking through the borders like there is no tomorrow;
• Third, it provides a successful way of legitimizing the actual "heirs" to the throne. They are basically worthless as leaders, but damn sure they would love to fill their father's or mother's vacant seat if they could;
• Fourth, it can lead to major upheavals in the balance of power, both inside and outside the unfortunate nation. 

...from now on, I'll take some liberties with your ideas, Mr. Climbe, but in general the basics stay the same.

How could it work exactly? Let's make it step by step:

1. Sovereign die. Shame. However, in the place of his throne an Altar appears;
2. Chaos reigns (i.e. no use of Essence, diplomacy... Climber described this already);
3. All legal heirs are given the option to go back to their Kingdom of origin, without spouses;
4. The Ark (or something similar) suddenly appears somewhere inside the Kingdom, rumor spreads among the elite that it might contain the essence of the last Sovereign;
5. His children now start to look for the Ark, backstabbing or making alliances with whomever they can. If they don't put their hands on that artifact fast, someone else will and that could end their pretensions;
6. Rumor spreads beyond borders, anyone with a bit of power thinks about going through the borders to rob the powerful magic item;
7. At this point, several people will be looking for the Ark - many factions and powerful individuals inside the target nation will be fighting over it, or not, it will depend on how effective the "main players" of that Kingdom are in exerting their hegemony;
8. After an unit finds itself carrying the Ark, it must return it intact to another Sovereign or to the Altar;
9. If another Sovereign touches the Ark, he will absorb its essence and become personally more powerful besides being able to claim the Sovereign-less nation's throne;
10. If an unit survives long enough to move the Ark to the Altar, the chief of this unit will become the new channeler. What do I mean? Prince Albert controls one minor faction and manage to get his soldiers to capture the Ark. They miraculously survive a perilous journey to his castle where he gather forces to march towards the capital. If they manage to arrive the capital and have him put the Ark in the Alter, Prince Albert becomes King Albert, gets new abilities and will work like a normal Channeler. Succession ends and he can start cleaning the mess;
11. Now, Prince Albert and Princess Katherina might fail - a pesky hero, friend of the old King, was smarter and got the Ark alone with his party. He manage to dodge the armies and sneak into the capital placing it over the Altar. Now that Hero becomes King or Queen;
12. Things can become REALLY interesting when you imagine other rogue creatures taking the Ark and becoming channelers. Remember that dragon you allied? Well, it seems he is interested in becoming King because he just killed the heroes bringing the Ark back home at the service of Princess Katherina and now is flying to the capital. Wouldn't that be awesome? I think it would;
13. The Ark destroying thing is also possible. Foreign forces might try to destroy it before the insider's forces capture it. As in the original idea, it would blast everything inside that nation, like a magic nuclear bomb. Game over for that fella.

About the affinity idea, I don't think that is very good. I believe allowing the heirs to automatically move to their motherland after his channeler parent is dead is fair enough. If one of them was married before and manage to assure the throne, s/he might be given options to forfeit that marriage or resume it. If s/he fails, he goes back to the country he was married and disappears. Now, one question that never goes out of my mind is what happens to the royal clutter? Uncles, grandchildren, etc. Worse, what happens to the Prince Consort or the Queen? Despite the Ark idea being the most puissant so far, it doesn't answer these questions.

I think the marriage system should be simple at the outset and get more complicated in an expansion.

If the game starts to make each and every aspect too complicated all at once, I think it could hurt it with a wider audience. For exampl,e this game is one that could bring my kids away from their Xbox into the strategy genre because of the fantasy setting. Nothing wrong with putting some aspects into the game so there is a foundation and then adding more complexity later on.

What about MY son. Can he inherit from ME? I find it a bit limiting if it is all one way succession. But that's me coming from not playing MoM so much. 

How easy would it be to make(mod) it all like a normal, expansive dynastic aspect of game?

This is fair enough.  My concern is that if different Factions have different methods of succession, it will add complexity and confusion to the game without adding much to strategic decision-making.  This may be a case of YMMV: some players may love the hard-to-discern politics of such a system; others may hate it.  I probably fall into the latter camp.

What would be interesting is for there to be two rule sets for Elemental: Basic and Advanced.  The Advanced rule set could have complicated things like "Succession Types based on Faction" vs. the Basic rule sets simpler system.

In response to RogueCaptain, my view is that the Successor should usually take all, if everything else lines up.  If there's good reason for dispute--the Successor is an illegitimate child, or a Champion and not of the Sovereign's family, or another character has low Loyalty, or another trait or traits, or the peasants are dissatisfied, or whatever--then maybe the Successor doesn't get all by default, and has to fight for it.

Coding the AI would be the easy part.  The hard--and frustrating--part would be for the player to keep track of it all.  With too many actions/counter-actions, the game becomes a crapshoot.

After reading the thread, I'm not really sure where to begin, so I think I'll just toss out some thoughts here.

In general, it seems like the proposed system (all your stuff goes to the ruler whose daughter/female descendent is married to your eldest son) is both a little too simple, and a little counter-intuitive, and could stand to be more complex. After all, this is something that only happens once a Soverign dies, and how many soverigns will there be in an average game? On the other hand, most of the complexity should be in the set-up of children and marriages, not in something that other players would need to do after your death.

Now, when you think about it, this isn't just a matter of the soverign deciding who is going to rule his kingdom when he's gone - from a simulation perspective it has to do with the behavior of certain NPC's. Really, there's two aspects - first is that the NPC citizens of your kingdom are deciding to follow your heir, and second your heir is deciding which of the other soverigns to ally with. It's not like Medieval Europe where there's a peerage and a king to make sure the laws of inheritance are followed, so what I would prefer is for the succession to be determined a little more organically.

I'm assuming every descendent is going to be a hero unit on the world map. And as such, they'll all have their own stats and abilities. I remember reading something in an interview about selectively breeding daughters to have a high 'beauty' rating, to better marry them off. Logically, you could also have a child who is a great leader, or a great warrior, a cunning politician, a channeler, and so on.

So what I'm imagining is a system that would take all of those factors into account in order to determine who takes the throne, or whether they have any rivals, and so on. Here's a rough sketch of how it could work:

The Soverign dies.

1. Potential Successors
   
   • By default, the throne passes to the eldest son. Or, let's say your oldest child of the same sex as the Soveriegn. Of course, if they're dead, it could pass to the second child, or to the eldest granchild, great grandchild, and so on, according to whatever rules of succession.
   • Other children can make their own claim. For that matter, another hero that's been recruited to your side could make a bid for the throne - this would probably be rare, but it might be a good thing to include if a Soverign dies childless, for example.
   • This would take into account a variety of factors such as age / line of descent (mainly so that your son, grandson, great-grandson won't all fight over the throne), overall capabilities (if the eldest son is mediocre, and the second son is awesome, there's a chance that the eldest wouldn't get the throne), and relation with your heir (if the second son hates the first, he's less likely to follow and more likely to try to take the throne for himself).
2. Popular Support
   • If there's more than one claimant to the throne, there's a question of who the people will follow. Each of the potential heirs tries to win as much support as possible, splitting the empire up between them.
     
   • All of your heroes (including descendents who aren't making their own claim to the throne) pick one side or another. Possibly, some of them could defect, leaving your faction and becoming wandering recruitable units or whatever.
   • Likewise, all your cities and military units would fall under the control of one faction or the other, with military units possibly going rogue again.
     
   • Loyalty is again determined by how closely related each candidate is to the former soverign, what their skills and abilities are, and so on. It could be influenced by proximity, supporting the hero that is physically closest to them on the worldmap. Heroes could sway a city or unit that they're in, and so on.
     
   • Once that's settled, check to see how much overall support each one has, how many cities, units, heroes they have on their side. If there's a significant difference, the more powerful one might be able to win and take over the entire kingdom (with the other possibly fleeing into exile). If they're closer to equal, then the kingdom is more likely to split with each rival ruling independently.
   • If there's only one heir, there still might be the risk of units and heroes defecting to join another faction or go barbarian, if the heir isn't a good enough leader to keep the whole kingdom together.
3. Kingom's Allegience
   • Once it's been determined who rules what, the heir (or heirs) joins up with one of the other soverigns, taking whatever cities, troops, and heroes remain loyal to them.
     
   • Who they ally with could be influenced by such things as diplomatic standing, geographical proximity, and, of course, marriage. If the heir is married into another soverign's family, they're more likely to go over to that soverign's side. If the heir is actually descended from you (due to them being the child of a political marriage) then evern moreso.
     
   • If your child is intelligent, beautiful, etc then they are even more likely to convince their spouse to join you. And having multiple marriages between the two families would mean tighter ties and a better chance they'll join you.
   • If they kindgom is split between two or more rivval heirs, each of them could potentially go over to a different soverign, leading to a bit of a civil war in the kingdom.

That may seem complex (or it might not, I don't know) but this is really something just AI, just like much of the other game mechanics, where the calculations and stuff take place behind the scenes within the space of a second or two on the turn the soverign dies. Players should still be able to tell, or at least make a calculated guess, what will happen when the soverign dies, and plan accordingly - it just shouldn't be as simple and boring as 'marry your daughter to their eldest son and you inherit the entire kingdom when they die'.

Just curious: how do games in the Europa Universalis series handle succession?  Do they have a good model?

In short, the previous system was based on marrying unspecified members of your royal family to other royals of friendly nations. This gives you a relations' boost, a way of claiming the crown of that given nation anytime and a dim chance of forming a personal union possibly followed by inheritance later by the death of one given monarch.

How personal unions are formed? Say, the Duke of Orleans dies without leaving a heir. From here, two things may happen: a Regency Council (more probable), that will rule the nation until the legal heir reaches adulthood or a personal union with one seemingly random nation holding a personal union. Personal unions can happen smoothly or violently, with the last option causing war to decide who, of two foreign, nations is taking the crown home.

And what is a personal union? Basically, is one nation being subject to another in military terms and in some economical ones. They are divided in Major Partner and Junior Partner, with the Major Partner being the ruler. The Junior Partner is not governed directly by the Major one, but is forced to ally itself unconditionally in any wars Major party is on. Also, it gives a little boost to your taxes, nothing too extravagant. A Junior Partner is also completely dependent on its foreign policy of the Major Partner i.e. it cannot declare war on its own.

The greatest advantage of being a Major Party is the increased probability of inheriting i.e. annexing the Junior Partner at some given time. This time is random but influenced by shadow statistics and it doesn't happen often. Personal unions can last for a long, long time without any annexation. They can also collapse very quickly, thanks to the pressure for some balance of power in Europe.

One thing I didn't discuss was the "claiming the crown" action. It allows you to gain a casus belli against any nation whom you have a royal marriage. This, however, is not advisable since it will destroy your relations with other nations whom you also have marriages.

Anyway, that's general scheme on how it was. 

EU III revamped its succession scheme in the last installment of the series conveniently named Heirs to the Throne. It has been around for two weeks and I still haven't put my hands on it but I can dig a thing or two about it, quoting developer Doomdark:

It seems dynasties have been properly implemented, with several clear factors balancing the transition of power instead of shadow statistics. I wish I knew more as it can probably be a source of inspiration.

PS: I've just discovered Crusader Kings has a powerful succession scheme - it might be worth giving it a look.

I agree, we need to know more about whether or not the nations in the game will use a Monarch or Feudalistic system, and whatever the devs decide I think it should remain that way throughout the game (rather than be able to change government types ala Civ 3) Frogboy mentioned using the series "a Song of Ice and Fire" as inspiration, and if you haven't read any of those books they use a feudal system. So if i had to place a bet, i would say Elemental will too (which is my hope ) but theres no telling just yet. I like your idea of multiple "dynasties" in one nation, because I could see a game where the different houses (which all reside in a city) all pledge allegiance to the sovereign (thus making up your nation). The outcomes of a scenario like this would always be different and unique and allow for a game to play out like the series above. I personally am a huge fan of "A Song of Ice and Fire" and so i would love for the game to follow it to a T, though I know it might not be everyone's cup of tea I do recommend it to anyone for the read, but I suppose we will just have to wait to hear more from the devs about how they plan to complete this succession idea... cuz all this specualtion isn't really getting us anywhere

Problems so far are the indecision of whether the death of a sovereign will mean game over or not, whether the children of the sovereigns will be able to inherit his/her channeler's trait and whether it is possible to be the head of state without being a channeler.

Without proper guidance, we are shooting in the dark.