Stronghold Defense, the defensive counterpart of the Lay Siege skirmish mode, gives players the opportunity to practice defending a prebuilt stronghold in a quick-paced skirmish. Defensive players have an impressive array of tricks available to set up before the invading army reaches their walls; set up spike traps or plant man-eating plants outside your gate to destroy your attackers, position cavalry outside of your walls to trample enemy units, and construct ranged siege weapons and dozens of other wall-mounted siege defenses.
You can see this new Developer Diary below: