Vassalage

[Animalpower]

I think the vassal system is not practical and seems unnecessary. Do you have any idea how can it be done?

If a player is stronger than other player he wants the weaker to become a vassal. So vassal should pay half of income if they become a protectorate/vassal. And also the protector of the vassal should protect the player with military.

 

[Dr Super Good]

I have a feeling most people will just leave if they fall into that state.

Perodicly you need to check for resource change (increase). You then remove half of that change and add it to the enslaving player. You then need to keep track on expendature when constructing units so that next period, the cost of the units get added to income delta to prevent people obscuring their income by building units. Additionally, you will need to provide a negative delta when a unit is canceled so that they do not get taxed twice on the same gold (unless you want to be like the United Kingdom...).