Ok, what we know/decided so far:
The gamemode is called Stronghold.
It's played on a large, random plains map
Your objective is to kill the enemy dummy (+1 multi)
Your objective is to protect your own dummy (multi = down to 1)
One round should take between 60 and 90 minutes.
There are 8 Resource spots scattered over the map(=Mines).
You have to hold those spots to gain resources.
With those resources, you can build Wall Parts, Towers, Gatehouses, Stairs, etc.
With those resources, you can upgrade your Mines so they give resources faster.
With those resources, you can build and upgrade buildings:
Fletcher, Weaponsmith, Armorsmith, Stables, Engineer(+Siege Camp), Church(+Chapel)
Building and upgrading those buildings allows your team to spawn with better equipment
Siege camps allow production of Siege equipment away from your base,
Chapel allows spawning away from your base.
All of this can be changed, nothing is set in stone. This is what makes sense for us right now by brainstorming, not by testing.
