Firstly, I like the idea of a sovereign creation screen - customise appearance and maybe some skill points - is the sovereign good at magic? Combat? trade? Diplomacy? Creating magic items? Other interesting skills that fine tune game play.  Make it's more of an RPG feel which I like. You could go a one off skills at creation - or a skill point to spend at each level which would mean a high level sovereign who specialised in combat could be a handful or a high level sovereign who specialised in creating magic items might get some options that others wouldn't etc.

I like the idea that a sovereign should automatically escape when attacked within his borders, I’d like to add that I think there should be a cost if they are out of their borders - something like the mana points you get when you level.  Spend five (the cost of a city) to return to the city of your choice.  If you don't have five then you really shouldn't be outside the safety of your boarders...

The MOM spell of return concept is also a good one - though the morale and combat strength of the dead sovereign’s armies should be drastically reduced while the sovereign is dead - making it the ideal time to launch an attack and capture his cities etc.

I'm going to chip in my two cents and say that I really like the essence loss on sovereign "death" idea.. It naturally fits into the essence system as is, which seems to be a matter of making difficult choices as to how to spend this limited resource. Think about it - if you want to send your sovereign into combat, personally slaying enemy armies Sauron-style, but there's a risk he'll die and lose x essence, then you need to keep x essence unspent if you want him to do battle.

-That's x essence you didn't spend founding new cities, thus expanding your economy and allowing you to maintain a larger/more advanced army to support him in combat.

-That's x essence you didn't imbue into a hero/champion, giving you a powerful unit to aid or replace your sovereign in combat.

-That's x essence that you didn't spend on a devastating spell that might've made the combat unnecessary.

So sending your sovereign into combat forces you to "spend" essence just like any of these other uses for essence, it's just that instead of "spending" essence directly you have to save a certain amount in case the sovereign "dies." Sure you could spend all your essence on champions/spells/etc and then still send the sovereign into combat, but without any other system in place to save him, you're taking a major risk of losing the game.

It's a great balance of risk and reward, which the "sovereign escapes if you're defending" idea is not - in that case you have tons of risk for little reward if you want to attack with your sovereign, and zero risk (but potentially plenty of reward) if you can use your sovereign in ways that force the enemy to attack, like pillaging caravans and such. It forcibly shifts sovereign use to defensive/passive aggressive actions, as opposed to essence loss which would let you use your sovereign however you like, as long as you pay the significant opportunity cost of saving some essence.

Yeah, what I mean by retreat is to keep the sovereign out of the front line armies when things get dicey. I agree that having a retreat 'button' is awful. Nothing fun about chasing a defeated army all over the map.

I'm all for sovereign death in any tactical battle = game over. There's some good ideas around territory and essence loss but I think it's a bit complicated and not very intuitive. Even a non-combat sovereign should still be strong enough to deal with any early game units and by the time your opponents have assassins or raiders then you should have some kind of army or magical defence to counter that. In GC2, if the Korath launch a surprise spore mine attack and take out your homeworld cause you didn't have a defender in orbit, it doesn't mean the game is flawed, it means you neglected your defense and got caught.

A system where you can flee tactical battles by exiting the battle map should work fine. As long as you play with a bit of caution, your sov shouldn't be in too much danger and it's all player-controlled. No worrying about territory, attacking/defending, or evasion. The same system also takes care of heros or elite units. It's always up to the player to weigh the tradeoff between being in the thick of a fight and potentially having your escape cut off.

As for fleeing being annoying, I'd have to say I agree. Chasing an army around in circles is pretty boring stuff. It might work to have fleeing on the strategic map based on how much movement you have remaining. If you moved full out last turn then you don't have an option flee. If you have any moves left, you immediatly get to use them after the battle. This way a sovereign that's sitting still will be able to run and regroup as long as their empire is somewhat secure, but once you're running there's no more option to flee a battle. It also keeps attackers honest, if you move flat out without proper scouting, you run the risk of getting trapped.

Of course, this won't be viable till Beta4

It may be nice if there were some high level spell that allowed you to invest a large ammount of essence into binding your caster's soul/mind to an item.

One possible way is how Sauron invested nearly all his self into a single ring that rendered him effectively immortal so long as it existed. Such an item could be set up to  require the item be brought to a specific place for you to regenerate. This type of phylactery would allow the possibility of reviving a fallen sovereign, though not assure it.

Another possibility is to allow sovereigns to tie their soul/mind to an item (possibly housed in a special type of building that has no use but to bind the sovereign) and their soul return there when they die. They could then cast certain spells from the item but could not attack or defend physically. They could be given the possibility of possessing a new body, though it would be physically frail in comparison to their original body and there may be a possibility of failure to gain control of a new body.

A third possibility is for your sovereign to render himself undead. Turning yourself into a sufficiently powerful undead  being would either allow you to regenerate health quickly under certain circumstances (such as a vampire) or prevent you from being killed unless your body was completely destroyed (such as a lich). A vampire sovereign might be able to regenerate after being killed if there were a sufficent ammount of blood available. A lich might slowly "piece himself together" over time if not truely destroyed.

TL:DR=It should be possible to render your sovereign unkillable by normal means through sufficient investment of essence.

To be undead first you need the Sovereign to die. If the Sovereign dies = game over then explain me how to become an undead and not lose the game.

Thinking about how I would be playing the game: if Sovereign loss cost is too high, I would simply save before each combat, and load if the result is not to my liking.  That would negate the whole point of imposing penalties for losing the fight.  So, speaking for myself (and, I suspect, a great many gamers who are not nearly as hardcore as most of the people here), imo either the cost has to be 'just' but low enough that most gamers will simply take it and get on with the game, or there should be an opt-out in the game creation screens for something like the aforementioned.

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I don't know where the overall flavour of the game is heading, but if I might suggest something, partly my own, partly borrowed from others who have already posted:

1. In own territory, whether attacking or defending, the sovereign counts as defending his own lands, and will always escape when losing "Local inhabitants helped the Sovereign to escape to the nearest city."  Then put the sovereign in a city nearby that does not have enemies right next door (if available), put him out of action for a turn or two to heal.  (And if he's then attacked in that city and loses again, it's game over?)

2. In neutral or allied territory, "The Sovereign escaped the disaster, and after much hardship, returned home."  Sovereign is relocated all the way back to the capital, and is out of action 5 turns or so, recovering from the ordeal.  (This would allow the sovereign to be used for initial exploration.)

3. In enemy territory, a loss, in attack or defence, can result in the Sovereign being captured.  (The sovereign should always be the last unit in a stack to defend, except if the player changes that).  If he escapes, see option 2, if not, the war ends, and depending on relative strength, the enemy takes techs, money, and/or cities.  If you've got nothing of value to trade, i.e. you've all but lost already anyway...  (Maybe an option for the more hardcore, if you deny the ransom demand, the sovereign is killed, and a successor takes the throne (i.e. you receive a new sovereign at either base, or at least, much lower level.))

This system worked very well in the various KOEI strategy games.

I don't know how the real time battles are going to run, but the image I always had in my head was your sovereign was a cool little unit on the field (if he is in the fight). I also had it in my head that if that unit's life dropped to zero he was dead dead dead. That way it would encourage me as a player to not only protect my sovereign, but to use him carefully. So I could have a monsterly powerful unit who I wouldn't have to worry about as much because he's a demi-god style deity. Or I could have him as a complete support sovereign (building cities, nice helpful magic) who I wouldn't send into battle and if I did he wouldn't technically fight.

The reason I say this is because if the offspring system works out, then I can have my character's children kick ass in my stead, and breed some awesome line of warriors while my sovereign was technically the pansy of the family. But that would always take a back seat to my sovereign being the ass kicker who brings down fiery rains of meteorites (as in that would be the cooler option imo). That being said I think it would be interesting if when your sovereign died it wasn't game over, but as his family lived on you could win with them. This would certainly open up interest options when fighting enemy sovereigns. If you perchance slew their leader, you could hunt down and exterminate his offspring who are keeping the remains of his empire together. Or even make an alliance with them! It could open up interesting new challenges etc that could just add a bit more depth to it.

But personal opinion: if your careless enough to let your sovereign get eaten (when you can make him an awesome in game soldier or simply hide him!) then its your own fault! At least if this isn't the case, for instance it is probably a little unfriendly having your sovereign getting squished ending your game or ridding you of your most powerful/useful unit, there should be a game mode where it is! I would find this highly interesting!! Then you could have a whole slew of options in battle, like whether you want to tell your sovereign to high tail it out of there because the enemy are just pumelling you senseless (with fun repercussions like people thinking your dude is a coward because he runs!) With just enough interesting perks to stop you from simply fleeing all the time as soon as things go wry.