In ancient and medieval times, warlike people devised various ways of dealing with heavily fortifies cites and castles....
One way to capture a fortress was via an assault. This consisted of bashing in the gates, busting open the walls, building towers or ladders to go over the wall, and so forth. It was a fast and bloody method, many attackers would die. Assaulting a city is already well represented in Warbarons.
Another way to deal with a fortress was through a prolonged siege. The besieging army would surround the enemy city, and then wait until starvation caused the defenders to surrender...or weakened them as a prelude to an assault.
In Warbarons, sieging a city gets you nowhere. If you sit an army next to an enemy castle, enemy troops can still come and go as they please, and can even be vectored there from distant cities. Surrounding a city would take a huge amount of units (each city is surrounded by twelve areas) and wouldn't stop vectoring anyway.
I would like to be able to play the waiting game, and slowly squeeze an enemy city to death. Here is my idea for a siege mechanic.
If I move a stack next to an enemy city... and it survives until the next turn, I get the option to turn that stack into a siege tower (instead of moving the stack). A picture of a siege tower replaces the unit picture for the stack... to show that the city is under siege. Vectoring to a city under siege is blocked...the units remain in 'vectorland limbo' until the siege is lifted.
Units inside a city would have enough food for a number of turns equal to the city's wall bonus (1,2 or 3 turns worth of supplies) after that they begin to starve. once starvation begins production would halt, and each stack inside the city would loose its weakest unit. This loss would happen at the start of the besieging player's turn and would happen every turn until either; all the defending units are dead, or the siege is lifted.
The siege would be lifted when all the siege towers surrounding a city are destroyed or choose to move away.
I think players could wrap their heads around this mechanic fairly easily, and it would allow for lots of fun siege related activities...like sallying out of the city to attack a siege tower...or hastily marching an army to relieve a city under siege.