So one thing that seems to rise from time to time is between players that want to be able to conquer others towns, with players that feel that it would be too harmful for the playerbase, what if we implemented a vassal system?
Just a rough idea of how it could work, I bet with plenty of suggestions it can be made a lot better.
Conquering a town
When you attack a town you have a new option - Conquer
This would require you to beat the entire army under the 20 rounds
plus destroy a building (say something like a citadel? upgradable structure?)
they would need to keep control of said town for X time (say 24h should be enough time for any allies to help if there are any)
If you're successful congratulations! You are now a Lord and have a new vassal!
Vassal Cities Duties
Vassal cities are still controlled by the player exactly as before.
The Lord though would require a tribute, a % (or fixed) ammount of the resources per hour. This rate would have a minimum (of 0%) and a maximum (25%?) that the Lord could change. This way it incentivize the conqueror to actually build a relation with the vassal by being able to reward him or punish him if he tries to rebel.
The Lord can keep an army in the town and see the army stationed on the vassal town while he keeps an army there (or he can only see part of the troops to make it more balanced?)
If at any point the vassal desires to no longer be a vassal he need to kill the Lords troops in his city, if there are no troops in his city he can just declare to not be a vassal any longer (this could also have a timer as well for the lord to reclaim the town before it stops being a vassal, it should be rather smaller than the one needed to conquer as keeping vassals by bruteforce alone should be expensive)
I think this could be fun, being a vassal can actually be a good thing, you gain protection from your lord (he has an incentive to defend you because if he gets a % of your resources and if he lets someone raid you and his army is killed you can just stop being a vassal), and if you actually get in touch with your lord / vassals you can work together for a common goal, the good lord will want his vassals to grow and will probably keep the % lower so they grow faster as he'll get more resources that way and probably enlist the vassals help on future fights. It can also probably help slower players by making an asset to have them as a vassal growing, instead of constantly raiding them, which will end up being more enjoyable for them and easier than keep the admins on check to make sure no newbie bashing happens. An oblivious player might not even notice the % decrease on his resources and continue to happily play. Ofc that a Bad lord will probably set the % to the maximum but will have to keep an iron fist over all his vassals as they'll be plotting to get rid of the control by themselves, start a rebellion with the other vassals to get free or they might bargain with another powerful neighbor to be there vassals instead in exchange for help and better % rates.